Understanding Actions, States, and Events: Verb Learning in Children with Autism 9781614510864, 9781614510949

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Understanding Actions, States, and Events

Studies on Language Acquisition 45

Editor Peter Jordens

De Gruyter Mouton

Understanding Actions, States, and Events Verb Learning in Children with Autism by Susan Douglas

De Gruyter Mouton

ISBN 978-1-61451-094-9 e-ISBN 978-1-61451-086-4 ISSN 1861-4248 Library of Congress Cataloging-in-Publication Data A CIP catalog record for this book has been applied for at the Library of Congress. Bibliographic information published by the Deutsche Nationalbibliothek The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available in the Internet at http://dnb.dnb.de. 쑔 2012 Walter de Gruyter GmbH & Co. KG, Berlin/Boston Printing: Hubert & Co. GmbH & Co. KG, Göttingen ⬁ Printed on acid-free paper Printed in Germany www.degruyter.com

In memory of Roger Julyan Wales and Donald Marder Douglas

Acknowledgements

This book is based on my doctoral dissertation and there have been many people who have contributed to its development to whom I would like to express my gratitude. I would especially like to thank the Australian families who so willingly participated in my research project; their generosity in allowing me into their homes and into their leisure time was a privilege for which I am very grateful. My particular thanks go to ‘David’, ‘Peter’, ‘Liam’, ‘Kevin’ and ‘Joseph’ who so readily and enthusiastically accepted my presence, and made data collection a most enjoyable experience. I would also like to acknowledge Brian MacWhinney and colleagues for the creation of CHILDES, and Helen Tager-Flusberg for contributing the transcript data for the American children with autism. I would like to thank my thesis examiners – Sue Leekam, Paul Bloom and Rosalind Thornton – whose astute comments and suggestions played a central role in the shaping of this book. Many thanks, too, to Emily Farrell at Mouton de Gruyter for guiding me through the publication process. I am exceedingly indebted to my supervisors Hilary Chappell and Roger Wales who have offered encouragement and insightful guidance throughout my PhD candidature and beyond. I am particularly grateful for Roger’s advice during the writing of this book and for his kindly persistent inquiries about its completion. Finally, my heartfelt thanks go to James for his patience, encouragement and the many hours of assistance, and to Charlotte and Lily for the daily experience of child language development and numerous other joys.

Contents

Acknowledgements Chapter 1 Introduction 1. Motivation for the study 1.1. Theories of word learning 2. The study 2.1. The children 2.2. Communicative abilities of the children 3. Outline of monograph Chapter 2 What is autism? 1. The emergence of autism as a syndrome 2. Autism: The current perspective 2.1. Autism and behaviour 2.2. Autism and aetiology 2.3. Autism and cognitive abilities 2.4. Autism and language 3. Diagnosis and assessment 4. Conclusion Chapter 3 Understanding actions, states and events: Verb learning in children in children with autism 1. Introduction 2. Preliminaries 2.1. The study 2.2. Semantic categories 3. Semantic profiles by category 3.1. Activity 3.2. Change of state 3.3. Stative 3.4. Deictic

vii 1 1 2 9 9 10 11

13 13 18 19 23 25 34 39 42

44 44 45 45 46 47 47 51 53 56

x

Contents

3.5. Desire 3.6. Emotion 3.7. Perception 3.8. Communication 3.9. Mental state 3.10. Causative 3.11. Abstract 3.12. Modal auxiliaries 3.13. Misuses 3.14. Lexical innovations 4. Overview 4.1. Semantic profile of verb use 4.2. The developmental path of verb acquisition 4.3. Lexical diversity 5. Conclusion

58 61 64 67 69 72 75 78 81 83 84 84 85 88 91

Chapter 4 Understanding space and time: Preposition learning in children with autism 1. Introduction 2. Theoretical background 3. Semantic profiles by category 3.1. Spatial 3.2. Temporal 3.3. Abstract 3.4. Grammatical 3.5. Misuses 4. Detailed examination of the prepositions in, on, up, and at 4.1. In 4.2. On 4.3. Up 4.4. At 5. Overview: Developmental flowchart 6. Conclusion

93 94 95 95 100 102 105 107 109 109 114 118 121 126 129

Chapter 5 Verbs of thought, desire, and speech in grammatical development 1. Introduction

130 130

93

Contents

2. 3. 4. 5. 6.

Verbs of desire Verbs of cognition Verbs of communication Summary Theory of mind and complex clauses 6.1. Theory of mind development 6.2. Syntactic complements and theory of mind development 6.3. Verbs of communication and theory of mind development 6.4. Complex sentences and theories of language acquisition 7. Conclusion Chapter 6 Issues and implications 1. Overview of study 2. Semantic development 3. The effect of autism on the interrelatedness of verbs and prepositions 4. Theory of mind and complementation 5. The origin of grammar: A perspective from autism 6. Final comments Notes References Index

xi 131 135 138 142 143 143 147 150 152 160

161 161 163 172 175 177 182 185 186 222

Chapter 1 Introduction

1. Motivation for the study The process of verb acquisition in children with autism is an intriguing issue when you consider the complexity of this lexical category. Not only do verbs express concepts such as actions, events, or states, but verbs (at least in English) also carry information about the number and nature of participants, and temporal information about the completeness of the activity and the time at which the activity occurred. Learning verb meanings is also often intertwined with other cognitive skills such as the recognition that human action is motivated by beliefs and desires. Thus, while the focus in child language studies more broadly has been on object names, verbs are central to the process of language development. The question of how children with autism learn the meanings of verbs has received similarly modest attention and there is little consensus in the available literature regarding how knowledge of verb categories in children with autism compares to typical development. The general process of lexical acquisition in children with autism is a widely debated issue. One view is that an element of the language impairment associated with the disorder is a categorization deficit, which limits the acquisition of lexical items much beyond a perceptual level (Klinger and Dawson 1995; Shulman, Yirmiya, and Greenbaum 1995). The alternative perspective is that conceptual organization is unimpaired but that individuals with autism have a reduced capacity to use this information at a functional level (Tager-Flusberg 1985a; 1985b; 1991; Rapin 1996). However, the process of verb acquisition in children with autism is a somewhat understudied area of lexical development, with the acquisition of object labels being the primary focus for much research investigating the nature of the proposed categorization deficit in autism. Where researchers have considered semantic development beyond object labels, they have targeted areas known to be problematic for children with autism such as psychological state terms and deixis (Eskes, Bryson, and McCormick 1990; Fay and Schuler 1980; Hobson 1993; Lee, Hobson, and Chiat 1994; Loveland 1984; Tager-Flusberg 1993). Furthermore, those studies which have investigated general lexical development have centred on the broader issue of form class distribution (Tager-Flusberg et al. 1990; Williams 1993). The form a profile of semantic

2

Introduction

development in verbs for children with autism might take was postulated by Menyuk and Quill (1985). However, a profile of verb acquisition in the language of children with autism which is based on empirical research has not yet been undertaken. 1.1. Theories of word learning Interest in the issue of vocabulary development in typically developing children has an extensive history, and a number of theories in various forms have been posited to account for the acquisition of word meanings in children’s language development. These theories are reviewed here to construct a theoretical framework for the analysis of verb acquisition in autism and I also discuss the question of what constitutes meaning. 1.1.1. The meaning of meaning: The problem of induction The question of what it is to know the meaning of a lexical item is central to the issue of how children learn to map concepts to words. While word learning has often been considered one of the more straightforward aspects of language acquisition, the complexity of the task is exemplified in Quine’s much quoted illustration of the linguist trying to learn a language other than his or her own: a native speaker points to a rabbit running by and says “Gavagai!”. The linguist must establish whether gavagai is an object label meaning ‘rabbit’, a property of the rabbit, the action of the rabbit running or any one of an almost limitless number of possible definitions (Quine 1960). In the context of language acquisition, the dilemma described by Quine is encountered by all children acquiring language each time they learn a new word. Nonetheless, the rate at which children acquire new words suggests that they are quite adept at the task. The challenge for researchers is to account for the extremely rapid process of word learning in typical development: that is, to ascertain how children navigate the inductive process of word learning. A further issue is the question of what it is to talk about the meaning of words. Many philosophers have argued against the idea that words can have meanings, or that meaning is anything more than a sensory response to stimulation (Hume 1739; Locke 1690; Quine 1960). However, as P. Bloom (2000: 17) noted, any discussion of semantic development in children entails adherence to the view that word meanings exist and that they can be learned. Similarly, subdisciplines of linguistics such as lexicography and semantics,

Motivation for the study

3

including the theories of Natural Semantic Metalanguage (Wierzbicka 1996), Semantic Field Theory (Lyons 1977) and Prototype Theory (Taylor 2003) are founded on the premise that word meanings can be identified. Thus, following Bloom, I consider word meanings to be the mapping of mental representations, or concepts, to linguistic forms.

1.1.2. Associationism One of the most enduring theories of word learning is associationism. That is, the idea that children learn the meanings of words by associating a particular word with the experience of an object or event at the time the word is uttered. For example, children learn the meaning of a word such as dog by encountering category members in the presence of the category label. Conversely, the properties of animals belonging to the category dog stimulate the category label. Associationist theories of language learning have been prevalent within the fields of psychology and philosophy for many years (Hume 1739; Locke 1690; Skinner 1957) and continue to appear in current theories of language acquisition (L. Bloom 1994; Plunkett 1997; Richards and Goldfarb 1986; Smith 2000). Associationist accounts of word learning have intuitive appeal because the mapping of words to meanings via associative experience is logical. Examination of children’s early words reveals that the majority of these first words are grounded in sensorimotor experience. Moreover, children encounter many object labels through adults drawing their attention to items while naming them. However, associationism as a theory of word learning is quite problematic. While children may learn some words by ostension, not all words refer to concrete items or observable events and the practice of naming objects is not universal (Lieven 1994; Schieffelin 1985). Further evidence against associationism is found in the fact that a number of children’s early words refer to activities and states. Moreover, many eighteen-month-old children produce and comprehend such abstract terms as love and bad (Dale and Fenson 1996). The associationist approach also entails that children will make many mapping errors in their early extensions of words. However studies have shown that word learning is both rapid and surprisingly error free in young children (Carey and Bartlett 1978; Markson and Bloom 1997; Rice 1990). Hence, although word learning involves the association of a word to a concept, associative mechanisms, alone, cannot comprehensively account for the process of lexical development.

4

Introduction

1.1.3. Biases and constraints An alternative explanation to account for the rapid process of vocabulary acquisition is that young children approach word learning with implicit biases (Golinkoff, Mervis, and Hirsh-Pasek 1994; Markman 1989; 1994; Waxman 1990). Thus, rather than analysing all possible hypotheses about the nature of categorization and only discarding them in the face of negative evidence, children and infants are predisposed to reject some hypotheses. The role of these assumptions is to limit the number of hypotheses children need to consider when faced with the task of sorting category labels. A number of researchers have questioned the necessity of postulating specific constraints to explain the process of vocabulary acquisition (P. Bloom 2000; Nelson 1988; 1990). P. Bloom (1994a) noted that the majority of constraints outlined above address the acquisition of object labels. While there are studies which have considered the application of word learning constraints beyond object categories (Golinkoff, Hirsh-Pasek, Mervis, Frawley, and Parillo 1995; Soja, Carey, and Spelke 1991; Waxman 1999; Waxman and Markow 1995), the issue of how highly abstract terms such as love and under are acquired via these constraints remains unresolved. Moreover, studies examining the ability of children to acquire novel facts about objects revealed that biases such as the mutual exclusivity assumption are not restricted to word learning (Diesendruck and Markson 2001; Markson and Bloom 1997). An interesting alternative to the biases and constraints outlined above is Clark’s (1987; 1997; 2003) two general pragmatic principles for word use: the Principles of Contrast and Conventionality. Under this approach, children assume that each different word in the language environment has a different meaning (Contrast) and that particular meanings have a conventional form that should be used in the language community (Conventionality) (Clark 2003: 143-144). This difference in meaning of the Principle of Contrast reflects variation in conceptual perspectives. That is, a dog could be “our pet”, “Spot”, “an animal”, or simply “the dog”, depending on the perspective chosen by the speaker (Clark 1997). The principles are similar to the mutual exclusivity assumption, but are derived from other cognitive skills, rather than being biases and constraints specific to the process of word learning. Clark’s principles are founded on the premise that the necessary cognitive skills to promote the rapid vocabulary growth identified in children are found in more general pragmatic skills. This is precisely the view held by researchers in the social-pragmatic approach to word learning.

Motivation for the study

5

1.1.4. Theory of mind and semantic development The social-pragmatic account of vocabulary acquisition stipulates that children learn the meanings of words by focussing on the communicative intentions of others in the language environment. That is, it is theory of mind abilities which enable children to navigate social interactions through which they constrain interpretative possibilities of actions and events (Nelson 1985; Tomasello 2001). This approach eliminates the need for language specific constraints or biases, for these biases are explained in the context of a child’s attempt to understand the communicative intentions of the people around them. Researchers investigating lexical acquisition in typically developing children identified a relationship between the early theory of mind skill of joint attention and vocabulary development in young children (Rollins 1999; Tomasello and Farrar 1986). More particularly, studies revealed that children apply novel labels to items only on the basis of the experimenter’s intentions. Baldwin (1991) found that eighteen-month-old children determine that a novel label refers to the object on which the experimenter is focussed, even if the child is playing with another item at the same time the novel name is uttered. Similarly, children can acquire a novel label for an object when the object is initially unseen, and the child is encouraged to devote his or her attention to another object (Baldwin 1993). However, in a further study, Baldwin, Bill, and Ontai (1996, cited in P. Bloom 2000) demonstrated that fifteen- to twentymonth-old children do not acquire an object label when they are playing alone in a room with a novel object and the novel name is uttered by a person outside the room. Tomasello and Barton (1994) found that twenty-four-month-old children could apply a novel label on the basis of the intentional cues provided by the experimenter under two conditions. In the simple version of the experiment (Without Search condition) the experimenter approached a series of buckets after providing the novel label for the target object, and excitedly extracted a toy from the first bucket. In the complex version (With Search condition) the experimenter provided the novel label, but upon approaching the buckets, selected and rejected two toys accompanied by nonverbal cues of dissatisfaction, before selecting the target object and expressing excitement. A further experiment revealed that children were using more than the experimenter’s emotional responses as a cue (Akhtar and Tomasello 1996). This experiment was very similar to Tomasello and Barton’s (1994) study, but within the row of buckets there was a distinctive toy barn and the experiment included a familiarization phase. For this pre-test phase, children participated

6

Introduction

in a finding game which enabled them to become familiar with objects in each container. Once again, there were two conditions in the test phase: after the novel label was provided, the experimenter went straight to the toy barn and retrieved the target object in the Referent condition, but in the Absent Referent condition, the experimenter found that the toy barn was locked. Despite the absence of a visual identification of the target object in the Absent Referent condition, two-year-old children still acquired the novel label, as did eighteenmonth-old children under the same conditions (Tomasello, Strosberg, and Akhtar 1996). Children are also sensitive to more complicated pragmatic cues in the process of word learning. Akhtar, Carpenter, and Tomasello (1996) undertook a study in which the cues to the referent of the novel label were quite subtle. Two-year-old children played with three unnamed, novel objects, accompanied by a parent and two experimenters. After one of the experimenters and the parent had left the room, a fourth unnamed object was introduced to the playtime by the remaining experimenter. Upon re-entering the room, the other experimenter exclaimed “Look, I see a gazzer!” while looking at all four objects. Despite the fact that the target object was not singled out, the children still determined that the novel label referred to the object introduced after the experimenter had left the room. For older children, Sabbagh and Baldwin (2001) found that children aged between three and four more readily acquired a new word when the source of information was a knowledgeable speaker. Moreover, the more sophisticated theory of mind abilities of the four year olds meant that they could still acquire a novel word, even when the knowledgeable speakers expressed hesitancy. Despite the important role theory of mind plays in the process of vocabulary acquisition, children must first learn what constitutes a word in order for word learning to take place. As P. Bloom (2000) reasoned, theory of mind as a theory of vocabulary acquisition only constrains potential words to intentional communicative acts. Young children must establish that only words are symbolic for spoken languages. This knowledge appears to be in place shortly after eighteen months of age. Prior to this age, children can acquire novel gestures (Namy and Waxman 1998) and squeaky sounds (Woodward and Hoyne 1999) as object labels. Similarly, the concept represented in a word must be cognitively available to children, before they can acquire it. That is, while concrete items are relatively easy to acquire, words for highly abstract concepts such as mortgage, and those for which it is hard to map the word to the concept (e.g. think) are learned later in development (P. Bloom 2000; Gleitman and Gleitman 1997).

Motivation for the study

7

One bias which cannot be explained by theory of mind abilities is the whole object assumption (Baldwin 1989; Carey 1988; Golinkoff, Mervis, and Hirsch-Pasek 1994; Hall, Waxman and Hurwitz 1993; Markman 1989; Mervis 1987; Soja, Carey, and Spelke 1991). As outlined above, on the basis of this principle of lexical acquisition, children are predisposed to assume that a novel label applies to an entire object and not its parts or properties. Rather than being a product of theory of mind abilities, this principle has its origins in children’s knowledge about objects and object behaviour which is argued to be innate. Babies have expectations about objects, such as one object cannot simultaneously appear in two locations and object movement is spatiotemporally continuous (Spelke 1990; Spelke et al. 1995; Xu and Carey 1996). 1.1.5. The role of syntax The role of syntax in vocabulary acquisition was first investigated by Brown (1957) who suggested that children might be sensitive to the grammatical encoding of word classes in their attempts to understand the meanings of words. In order to test his theory, he conducted an experiment in which preschoolers were divided into three groups: to the first group, he showed a novel action being performed on a novel object with the linguistic cue “Do you know what it means to sib? In this picture, you can see sibbing”; to the second group he showed the same picture but with the linguistic cue “Do you know what a sib is? In this picture you can see a sib”; the third group also saw the same picture and were given the linguistic cue “Have you seen any sib? In this picture you can see sib”. All three groups of children were subsequently shown three pictures depicting the same action, the same object and the same substance and were asked to point out the action, the count noun, or the mass noun, depending on which group they were in. Brown found that the children in the verb group consistently picked out the picture denoting an action, while the other two groups picked out the count noun and the mass noun, respectively. Other research has been conducted on the basis of Brown’s results to test the extent to which syntax facilitates meaning mapping. Many studies have shown that children are sensitive to the syntactic difference between count and mass nouns in their extension of novel nouns to individual items and collective substances (P. Bloom 1994b; Katz, Baker and McNamara 1974; McPherson 1991; Soja 1992). The facilitative role of syntax in the acquisition of meaning for other lexical classes has also been established. While novel

8

Introduction

nouns encourage categorization on the basis of object similarity, novel adjectives direct the attention of young children and even twelve-month-old babies to properties of objects (Smith, Jones, and Landau 1992; Taylor and Gelman 1988; Waxman 1999). Similarly, children acquiring English are sensitive to the encoding of spatial relations via prepositions (Landau 1996; Landau and Stecker 1990), the distinction between transitive and intransitive verbs (Naigles 1990) and the unique complement-taking syntax of verbs of cognition and communication (Gleitman 1990; Lederer, Gleitman, and Gleitman 1995). Despite the useful role syntactic bootstrapping plays in the development of meaning, it is not a sufficient skill for the process of lexical acquisition. While syntax can provide even very young children with information about the type of meaning being encoded by a word, such as adjectives versus nouns, countmass noun distinctions and words for spatial relations or events, these cues cannot provide access to exact word meanings (P. Bloom 1994a; 2000; Pinker 1994a). Rather, the ability to utilize syntactic cues works synergistically with the other skills necessary for word learning outlined previously. 1.1.6. Summary Children are extremely rapid word learners and begin the acquisition of abstract concepts at a remarkably early age. An adequate theory of vocabulary development must be able to account for this process across all lexical categories. Thus, while associative learning does play a role in lexical acquisition, particularly in ostensive contexts, associationism has limited application beyond the acquisition of words for concepts grounded in sensorimotor experience. Moreover, the extensive mapping errors predicted by associationist theories do not occur in typical development. The biases and constraints offer a better account of the word learning process. However the constraints have limited scope beyond object labels and observable actions and events, and are not necessarily specific to word learning, but may be explained by theory of mind abilities. The results of the studies discussed above indicate that theory of mind abilities play a significant role in the process of word learning: joint attention skills promote vocabulary development and the ability to infer the communicative intentions of others provides the major source of information in the acquisition of new words. Nonetheless, children must first recognize the symbolic nature of words, as well as develop sufficient cognitive maturity to understand the concept represented by a word. In summary, the process of vocabulary acquisition is

The study

9

contingent on the ability to interpret pragmatic cues and is facilitated by other skills such as the use of grammatical information to identify word classes. 2. The study 2.1. The children The children who participated in the present study included five children with autism from the United States who were part of a longitudinal study of language acquisition (Tager-Flusberg et al. 1990). These children were diagnosed using Rutter’s (1978) criteria cross-checked with the Diagnostic and Statistical Manual of Mental Disorders (third edition) criteria (American Psychiatric Association 1980). Five children with autism from Australia matched on chronological age to the US children were also recruited as participants. All of these children had received a formal diagnosis based on the DSM-IV (American Psychiatric Association 1994) criteria provided by a recognized child mental health service. At the time of the original study (Tager-Flusberg et al. 1990), the children from the United States were all living at home with their families, whose socioeconomic status ranged from lower to upper middle class. The children were either attending a special day school program or were participating in a home-based intervention program and were sourced for the study through the programs they attended. Those children who were selected demonstrated evidence of productive language and although high functioning autism was not a determining criterion, four of the five children fell into the low-normal to normal IQ range. Performance IQ was assessed using the Leiter International Performance Scale. All children were monolingual speakers of English and language level was measured by mean length of utterance (MLU) at the level of the morpheme. Table 1. Details of children from the United States Child Stuart Rick Brett Jack Mark

Age 3;4 4;7 5;8 6;9 7;7

IQ 61 94 108 91 75

MLU 1.17 1.73 3.74 3.03 1.46

No. of sessions 4 4 4 4 4

10

Introduction

As noted above, the Australian children who participated in the study had all undergone a team assessment from a recognized child mental health service. These assessments usually consist of a paediatric medical and developmental assessment, a communication assessment, a cognitive assessment, behavioural observations and child psychiatry consultation. The children were all living at home with their families whose socioeconomic status ranged from lower middle to middle class. They were all enrolled in special schools, mainstream primary schools, kindergartens or early intervention programs. Two children were attending both kindergarten and early intervention programs. All of the children selected demonstrated evidence of productive language, and information regarding IQ scores for each child, determined as part of the diagnostic procedures, was provided by the parents. Performance IQ was assessed using the Wechsler Preschool and Primary Scale of Intelligence – either the revised version (WPPSI-R) or the third edition (WPPSI-III). Four of the five children scored in the low-normal to normal range on Performance IQ. Each child was scored on the Childhood Autism Rating Scale (CARS) (Schopler, Reichler, and Renner 1988) as part of their formal assessment. These scores were also provided by the parents. Four children yielded scores indicating mild autism (30-36.5) and one child received a score indicating moderate to severe autism (37-60). All of the children were monolingual speakers of English and language level was measured by mean length of utterance (MLU) at the level of the morpheme.1 Table 2. Details of children from Australia Child David Peter Liam Kevin Joseph

Age 3;6 4;6 5;6 6;7 7;2

CARS 31 34 41 35 30

IQ 100 76 75 84 66

MLU 3.18 4.19 4+ 4+ 4+

No. of sessions 4 4 4 4 4

2.2. Communicative abilities of the children The MLUs of Stuart (1.17), Rick (1.73) and Mark (1.46) indicate they are in the first of Brown’s (1973) five stages of language development. They produce many single-word utterances as well as two- and three-word sentences. Jack (MLU 3.03) and David (MLU 3.18) are early Stage IV and their language use reflects the acquisition of grammatical morphemes and

Outline of monograph

11

production of yes/no and simple wh-questions, and complex sentences. Brett (MLU 3.74) and Peter (MLU 4.19) are early and late Stage V, respectively, in which the use of complex clauses increases. The remaining children (Liam, Kevin and Joseph) have MLUs above four at which point linguistic development is more subtle. The communicative abilities of the children also vary. While Stuart, Rick and, to a lesser extent, Jack, rarely initiate conversation, the remaining children do use language to get attention either to make requests or to share information. There are also a number of special features worth noting. The first is that many of the children engage in echolalia. The language of Stuart and Rick contains immediate repetition while David echoes an advertising jingle when he is upset and Jack’s language in general is substantially made up of delayed echoes from television. A second interesting feature is that Joseph often stutters quite badly. One final feature of the data is that the language development of the Australian children is clearly more advanced than the US children: three of the US children have MLUs of less than two, while the highest MLU is Brett’s at 3.74; in contrast, the lowest MLU in the Australian data set is 3.18, while three of the Australian children have MLUs above four which indicates they are beyond the final stage of Brown’s stages of language development. 3. Outline of monograph In this volume I examine the semantic development of verbs in the language of ten children with autism from transcripts of spontaneous natural language, collected over four sessions approximately one hour in length. While there are no studies which specifically examine verb acquisition in the context of a semantic profile, previous research regarding the ability of children with autism has yielded mixed results. While some researchers conclude that the semantic development of verbs is atypical in autism, others argue that while there is often evidence of delay, acquisition occurs in accordance with typical development. However, these studies have generally focussed on specific categories of verbs. For the present study, I hypothesized that the acquisition of verbs would proceed as documented for typically developing children where semantic categories overlap with concepts centred on sensorimotor development, but profile as disjointed for categories whose semantic properties are concerned with social knowledge and awareness of the internal states of others. The results reveal that while some children conformed to this profile, the verb use of other children demonstrated a surprising understanding of internal states – both their own and, in some cases, of others. Most

12

Introduction

particularly, there was no evidence to suggest that process of verb acquisition in children with autism is atypical. Chapter two presents an overview of autism as a developmental disorder. I consider the early delineation of autism as a syndrome, followed by current knowledge of the disorder including behavioural manifestations, aetiology, cognitive and linguistic profiles, and I present a review of diagnostic and assessment procedures. In Chapter three I examine the semantic development of verbs from the data collected in the present study. The chapter includes a theoretical background for the delineation of the verb categories, as well as a brief summary of the aims, participants, materials and procedures. The semantic profile of verb use is presented by category including sections on misuses and lexical innovations. The results are summarized in: a general semantic profile of verb use; a developmental flowchart of verb acquisition; and information regarding general verb diversity. In Chapter four I examine the semantic development of prepositions. This chapter includes a theoretical background on the lexical category, followed by preposition use in the language of the children presented by semantic category, including misuses. I undertake a detailed examination of four selected prepositions, before I summarize the results in a developmental flowchart. Chapter five examines in detail semantic and syntactic development in complex sentences within the verb categories of desire, mental state and communication, selected on the basis of their significance in the context of semantic development of children with autism. I present the results for complex sentences in each verb category, before I chart the theory of mind development as revealed in the transcript data. The chapter finishes with an exploration of syntactic complements and theory of mind development, and the relation of complex sentences to theories of language acquisition. Chapter six includes a review of the main findings from the present study and a discussion of the theoretical implications of the results. I also consider the limitations of the methodological approach alongside some suggested directions for future research. It must be noted that the data of a number of studies which will be referred to during the course of this monograph come from the full set of transcripts of the US children included in this study. However, the focus of the present investigation differs from these studies and any overlaps are acknowledged.

Chapter 2 What is autism?

1. The emergence of autism as a syndrome Historical accounts of autism reveal that the disorder has most probably always existed. Moreover, there are early case descriptions by clinicians which would now be recognized as accounts of autism (Frith 1989; Wing 1996). One of the most well known cases is that of the Wild Boy of Aveyron, a young boy estimated to be twelve years of age when he was found in a forest in France at the end of the eighteenth century. He had no speech, was not clothed and was not at all responsive to those around him. In sum, his appearance and manner were well outside the boundaries of social acceptability. The intellectual and fashionable public of the time were enthralled by this case and what the boy, known as Victor, revealed about the nature of a human who had existed outside human social structures. Particular interest was expressed in the question of whether or not Victor could be “civilised”. His education was undertaken by the physician E. M. Itard who wrote detailed reports on the progress of Victor’s schooling (Frith 1989: 19). Thus, much is known of Victor’s behaviour and Itard’s ultimately unsuccessful attempts to introduce the boy into society. The question of whether or not autism was a valid explanation for Victor’s apparent inability to be socialized was first considered by Harlan Lane in his study of the documented evidence relating Victor’s life (Lane 1977). While Lane discussed many similarities between Victor’s behaviour and that of children with autism (to be discussed in detail below) such as both hyper- and hypo-sensitivity to sound, profound withdrawal from human contact and an excessive desire for the preservation of sameness (1977: 176-178) he ultimately concluded that autism was not a correct diagnosis of Victor’s pathology. However, Frith (1989) argued against Lane’s assessment. She indicated that Lane’s objections to a retrospective diagnosis of autism are unfounded when considered against a more current understanding of the disorder (to be discussed in section 2). Moreover, evidence in favour of autism is to be found in a paper written in 1800 by the Professor of Natural History at the Central School for Aveyron, Bonnaterre, who discussed “evidence of a serious impairment in reciprocal social interactions” in Victor’s behaviour (cited in Frith 1989: 21).

14

What is autism?

While the case of Victor is one of the most well-documented, it is by no means an isolated example. The application of current knowledge of the disorder to early descriptions of unusual cases provides good evidence for the long history of autism. However, it was not until the pioneering work of Leo Kanner and Hans Asperger that autism was recognized as a syndrome and the first theoretical accounts of the disorder were presented. In an extraordinary coincidence, Kanner (1943) and Asperger (1944) worked simultaneously yet independently to describe the disorder which had hitherto remained unidentified. While each used the term “autistic” for the children they observed, this coincidence is less remarkable since the label was coined by Ernst Bleuler in 1911 to refer to the withdrawal from the world into the self, manifest in individuals with schizophrenia (Frith 1991). Through a series of case descriptions, first Kanner and then Asperger produced detailed and insightful accounts of the developmental disorder now known as autism. Kanner’s (1943) paper entitled “Autistic Disturbances of Affective Contact” included case descriptions of eleven children he believed to be suffering from the syndrome he called “early infantile autism”. Asperger’s original paper – “Die ‘Autistischen Psychopathen’ im Kindesalter” [‘Autistic psychopathy’ in childhood] was published in 1944 but was not available in an English translation until 1991. Consequently, less has been known of Asperger’s work and some misconceptions regarding his observations have arisen (Frith 1991). Despite the fact that neither Asperger nor Kanner were aware of each others’ initial investigations, Asperger’s descriptions reveal striking similarities to those presented in Kanner’s papers. For Kanner, the fundamental disorder he observed was the inability of the children to relate to people and situations from very early on in life, remarking “[t]here is from the start an extreme autistic aloneness that, whenever possible, disregards, ignores, shuts out anything that comes to the child from the outside” (Kanner 1943: 242). Asperger, too, believed that the central manifestation of the disorder was the inability to conduct social relationships. He noted that a frequent comment from the parents of the children he observed was “[i]t is as if he were alone in the world” ([1944] 1991: 78). While Asperger did comment on the profound withdrawal from social contact described by Kanner, he also attested that there were attempts made by some of the children to engage with other people. Nonetheless, these attempted engagements were considered further evidence of a disorder, since they often resulted in socially inept acts such as the demand of a service or opening a conversation on a topic of their choice with no consideration of common courtesies due to the addressee. An illustrative example of abnormal social interactions discussed by Asperger in his case descriptions was the behaviour

The emergence of autism as a syndrome

15

of Fritz V: “Fritz did not know the meaning of respect and was utterly indifferent to the authority of adults. He lacked distance and talked without shyness even to strangers. Although he acquired language very early, it was impossible to teach him the polite form of address (‘Sie’). He called everybody ‘Du’” (Asperger 1991: 40). Asperger commented that this type of aberrant behaviour was a result of a “genuine defect in their understanding of the other person” and not calculated acts of rudeness. Thus, these children appeared to be rude because they were oblivious to the social niceties which govern interactions with others. Another important observation made by both Kanner and Asperger relates to the lack of spontaneity in the activities of these children. Kanner’s assessment of their behaviour patterns led him to conclude that it is “governed by an anxiously obsessive desire for maintenance of sameness that nobody but the child himself may disrupt on rare occasions” (1943: 245). This intense desire for sameness leads seemingly commonplace occurrences such as changes in routine, rearrangement of furniture, loud noises or objects which move such as vacuum cleaners, even meal times, to cause great upset in the child. It may also result in stereotyped, or repetitive, body or limb movements such as finger-flicking and arm-tapping. Asperger (1991: 83) noted that the severe homesickness of some of the children he observed which would appear to contradict their paucity of emotional understanding could be explained in the context of their obsessional attachment to the objects and routines of home. That is, it was the absence of familiar environments and routines and the people who governed them which caused the distress, rather than the absence of the family members, themselves. Neither Kanner (1943) nor Asperger (1991) believed that there was a biological or a genetic connection between autism and childhood schizophrenia and they each recognized the prevalence of males suffering from the disorder. While Kanner originally believed that autism was observable from birth, expansion of case studies revealed children who demonstrated normal development in the first 18 to 20 months of life before lapsing into the classical account of detachment he described in his original paper. Thus, the clinical description was changed to “early onset” (Kanner and Eisenberg 1956: 93). Asperger, however, surmised from his original case studies that characteristic features were perceivable from the second year of a child’s life. Kanner’s later case studies also revealed that individuals with autism vary in the intensity to which they are affected by the disorder, an issue of which Asperger was also aware. Kanner and his colleague Leon Eisenberg argued that this emphasizes the need for primary diagnostic criteria as distinct from secondary features (1955: 82).

16

What is autism?

While the degree of similitude between the accounts of autism of both Asperger (1991; 1979) and Kanner (1943; 1946) is certainly noteworthy, there was by no means consensus regarding the features of the disorder. One of the key differences lies in their respective discussions of language ability: Of the eleven children Kanner described in his original sample, three did not speak at all and, for the other eight children, language served no communicative function but was mostly parrot-like with abnormal vocal intonation (1943: 243). The formation of original sentences was significantly delayed and the repetition of word combinations produced by others around them resulted in oddities such as delayed echolalia (the literal repetition of “stored” phrases) and pronominal reversal. In contrast, Asperger attested that the children he studied spoke fluently and that the highly intelligent ones “have a special creative attitude towards language”; he noted that they frequently used words beyond the expected capabilities of children their age as well as producing novel or partially restructured expressions, marvelling at their originality (1991: 70-71). However, Asperger did comment that language did not serve a communicative function for the children he observed, since speech is never directed to an addressee and the nonverbal communicative devices expected in normal development are absent. Despite Kanner’s interest in the fact that the children discussed in his case studies were born of highly intelligent parents of whom very few were “warmhearted”, in the original paper he ultimately concluded that early infantile autism is inborn: “We must, then, assume that these children have come into the world with innate inability to form the usual, biologically provided affective contact with people” (1943: 250). Asperger, too, argued in favour of an innateness theory. He asserted that autism is a “natural entity” and not attributable to exogenous causes, despite the very high frequency of only children who were observed. Asperger acknowledged that observers with a background in “individual psychology” would attribute the emergence of autism in an only child to the fact that he or she was surrounded by adults and, therefore, denied the necessary opportunity to interact with peers. However, he dismissed this as untenable in light of the fact that children with autism are not always the sole child of their parents and that the characteristics of autism are observable from such a young age. Moreover, Asperger insisted that the innateness of the syndrome is reflected in its constancy since, as Kanner and Eisenberg (1955) discussed, it persists into adulthood (1991: 87). Nevertheless, the tension between innateness and environmental conditioning remained problematic for Kanner, who believed that the coldness he observed in a large proportion of the parents contributed to their child’s condition.

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Another significant difference in the work of Kanner and Asperger pertains to the relationships of children with autism to the objects in their environment. Kanner argued that there is no evidence of disturbance; rather, the children he observed took great interest in objects they perceived to be non-threatening and would contentedly play with them for a long duration (1943: 246). This observation appears to be in direct conflict with that of Asperger, who contended that the relationship of children with autism to objects is, indeed, dysfunctional. He stated that objects are either ignored, or attended to with abnormal fixations, with the children he observed requiring the object to be always present or a temper tantrum would ensue (1991: 81). Frith (1991) noted that these very different postulations have not been widely considered and certainly warrant further investigation. A particular interaction with objects discussed only by Asperger and which is now recognized as a frequently occurring phenomenon is “collecting”. This, too, he argued demonstrates aberrant behaviour since the children do not collect items to play with but simply to possess. Some of the collections known to Asperger included matchboxes, cotton threads and boxes of junk (1991: 82). He also described collecting as a measure of social adaptation since these fixations with the accumulation of particular items often become more ‘rational’ in adulthood. The descriptions of motor abilities is another area in which Kanner and Asperger diverge. Asperger (1991) wrote of the clumsiness of the children he observed in every day matters as well as games requiring physical coordination. Moreover, he related that the children also revealed little dexterity in fine motor skills such as handwriting. While Kanner commented that a small number of the children he observed were a little clumsy in gross motor skills, including walking, he also asserted that all of them “were very skillful in terms of finer muscle coordination” (1943: 248). These contrasting analyses reflect their differing beliefs in regard to the relationship of children with autism to the world – namely that Kanner believed only relationships with people were impaired while Asperger held that relationships with their whole environment were defective. Interestingly, Asperger (1979), too, described the physical dexterity of children with autism in his later paper. Asperger did not produce diagnostic criteria for autistic psychopathy. However, Kanner summarized what he considered to be the essential characteristics of early infantile autism: “a profound withdrawal from contact with people, an obsessive desire for the preservation of sameness, a skilful and even affectionate relation to objects, the retention of an intelligent and pensive physiognomy, and either mutism or the kind of language which does not seem intended to serve the purpose of interpersonal communication” (Kanner 1949:

18

What is autism?

416). However, Kanner later concluded that only two principal diagnostic criteria were necessary, namely extreme self-isolation and obsessive insistence on sameness. He argued that other aspects of behaviour either stemmed from these two criteria or were non-specific to autism (Kanner and Eisenberg 1955; 1956). Other similarities between the descriptions posited by Kanner and Asperger include lack of imaginative play, unusual responses to sensory stimuli, behavioural problems such as tantrums and aggressiveness and special abilities which contrasted with other learning difficulties. Both authors commented on the remarkable rote memory and exceptional mathematical skill demonstrated by some of the children they observed. The nonverbal communication oddities such as averted gaze, paucity of facial expression and lack of gesture now considered characteristic of the syndrome were also documented by both Kanner (1943) and, more particularly, by Asperger (1991). They each remarked on the attractive and intelligent appearance of these children, although Asperger also documented the oddness of their appearance reflected in the absence of nonverbal modes of communication discussed above. While Asperger was unaware of Kanner’s work in his first publication, he certainly discussed the relationship of Kanner’s “early infantile autism” to his own “autistic psychopathy” in his later paper. According to Wing (1991) Asperger was first struck by the similarities but maintained the distinction of the two syndromes. However, in his second paper, Asperger (1979) was more focussed on the similarities and offered qualifications for the differences, suggesting that he believed in a strong relationship between his and Kanner’s work. He ultimately concluded that “early infantile autism” was a stronger manifestation of the disorder. There is no doubt that the contributions of Kanner to the establishment of autism as an independent syndrome are more widely recognized. However, both Kanner and Asperger were responsible for initiating the extensive research into the identification and clinical descriptions of the disorder which ensued from their original publications. Despite the differences in their accounts, the many strong similarities in their delineation of the features of autism focussed attention on the disorder and many of their insights form the basis for current perspectives on the autistic syndrome. 2. Autism: The current perspective Considerable advances in technology combined with intensive research over the last few decades have led to a greater understanding of autism as a

Autism: The current perspective

19

syndrome. More is known of the behavioural and cognitive features specific to autism but important questions remain unanswered. Ongoing research continues to address elusive issues such as organic pathology and primary cognitive deficits in order to build on current approaches to assessment and intervention. 2.1. Autism and behaviour Just as Kanner and Asperger originally defined the disorder according to the behaviours they observed, autism continues to be diagnosed on the basis of behavioural characteristics. However, the focus of research on the behavioural manifestations of the syndrome has fluctuated. In the interim between the identification of autism and current research, the theoretical approach has shifted from a belief that the autistic syndrome is the result of an unloving home environment to a focus on cognitive, perceptual and linguistic disorders rather than social behaviour, to a recognition of the importance of Kanner’s claim that the social deficit is central to the identification of autism (Mundy and Sigman 1989: 4). Emerging from this fresh consideration of behavioural characteristics has been an emphasis on the necessity of identifying the behavioural impairments specific to autism (Ungerer 1989: 75). A major difficulty of diagnosis at the behavioural level is the potential that clusters of features may occur by chance. Thus, the delineation of a set of necessary and sufficient features would justify the classification of autism as a separate syndrome and provide direction for investigation into both cognitive deficits and aetiology. The research of Wing and Gould (1978; 1979) has been particularly significant in the attempt to isolate the behavioural features specific to autism. They conducted an epidemiological survey of all children under fifteen years of age living in a particular area of London, screening those who were known to the social, educational, or health services. Children who had severe learning difficulties were selected from this initial group of 914 children, as well as those who showed evidence of social impairment, verbal and nonverbal impairment or stereotyped activities. This resulted in a group of 132 children who then underwent further examination. After comprehensive interviews with parents and caregivers and a series of observations and tests with the children, this group was divided into those who demonstrated appropriate social interaction and those who did not. While only 17 of the 74 participants from the socially impaired group embodied Kanner’s autism based on Kanner and Eisenberg’s (1956) two criteria (extreme self isolation and obsessive

20

What is autism?

insistence on the preservation of sameness), all participants had many features of autistic behaviour. Wing and Gould (1978) found that all 74 participants from the socially impaired group demonstrated repetitive stereotyped behaviour, and almost all had either an absence of language or language abnormalities, as well as a lack of symbolic, or pretend play. These features were not prevalent in the socially able group. Moreover, the same pattern of results emerged when the sample of 132 participants was divided according to the presence or absence of imaginative play. The marked co-occurrence of these three features led Wing and Gould (1978; 1979) to propose the impairments of social recognition, social communication and social imagination as a set of core features unique to and indicative of autism. I will discuss these features in more detail below. The identification of the three behavioural features known as the “triad of impairments” also proved significant in regard to defining the extent to which the diagnosis of autism may be applied. As noted above, only 17 of the 74 participants from the socially impaired group were considered autistic according to the diagnostic criteria postulated by Kanner and Eisenberg. Nonetheless, the three core features determined by Wing and Gould (1978; 1979) to be primary co-occurred in almost all of the sample. The results of this study led Wing (1988) to propose that autism, as identified by Kanner, is part of a continuum or spectrum of autistic disorders. Thus, while the triad of impairments is necessary and sufficient for a diagnosis of autism to be made, the manifestation of these impairments may vary between individuals and even within individuals across time and may also be accompanied by other characteristics commonly associated with autism. Wing (1997: 153) acknowledged that choosing impairments of social interaction as the diagnostic criteria has no validation in terms of neuropathology and is not necessarily the most superior system. However, the high degree of consistency of the triad of impairments has resulted in it becoming the basis for diagnosis of autism (Happé 1994; Rutter and Schopler 1987). Wing (1988) described the various ways in which the triad of impairments may be present in individuals with autism. She reinforced the importance of the spectrum in behavioural descriptions, stating that any descriptions must be read as selected points on the spectrum, since variation can occur. The first of the impairments of social interaction is that of social recognition. In its most severe form, an impairment of social recognition is apparent in the aloof or indifferent behaviour towards other people. Wing noted that individuals with this degree of impairment tend to ignore social or physical contact and may even actively avoid it (1988: 93). However, while some individuals display this aloofness at all times, others may engage with those around them to fulfil

Autism: The current perspective

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a need, reverting to indifference once this need has been met. In less severe cases, social contact is not initiated but such individuals will respond to the advances of others and allow themselves to be guided in activities. Another form of this impairment is revealed in individuals who do actively seek contact with others but do so in ways which appear odd to the other person. The oddness of this behaviour is due to the egocentricity of the individual with autism who is actively pursuing his or her own interests with no consideration of the other person. The most difficult-to-detect pattern of this impairment is present in adults who have learnt to adapt to their social impairment. Wing (1988) stated that such individuals give the impression that their knowledge of social interaction has been gained through intellect rather than intuition. The second impairment relates to social communication at both verbal and nonverbal levels, since this type of communication is not limited to speech. Wing highlighted the following types of social communication impairments discernible in individuals with autism: 1. a lack of desire to communicate at any level; 2. in a less severe form, engagement in communication is for the expression of needs only; 3. individuals with verbal abilities may make comments but they are not engaging in the act of conversation and their remarks are likely to have no relevance to the context in which they are uttered; and 4. some individuals with autism are quite talkative but they lack the intuition that guides a normal conversation and so they are likely to ask repetitive questions or talk endlessly about a topic of their choosing oblivious to the verbal and nonverbal responses of the listener (1988: 94). Studies have also found that children with autism do not use gesture as a means of social interaction or as an expression of emotions (Bartak and Rutter 1976; Ricks and Wing 1975). When gesture is used, it is to convey an immediate request such as “go away”, but gestures which convey states of mind are strikingly absent in the nonverbal communication of individuals with autism. The third and final impairment is the impairment of social imagination and understanding. In its varying degrees of severity, this impairment relates to the ability to understand the thoughts and feelings of others and to engage in pretend play. The various manifestations are as follows: 1. the absence of pretend play and mimicry; 2. mechanical copying of the actions of others without understanding of either their meaning or purpose but no spontaneous pretend play; 3. stereotyped role-play such as being an animal or a character from a television program that is enacted with fixed sameness and without empathy; 4. for older individuals with autism there can be an awareness that other people have thoughts and feelings but the ability to interpret or guess these is absent; and 5. There are individuals whose impairment is mild to the extent that they have learned to recognize the emotions of others using

22

What is autism?

intellect rather than empathetic understanding (Wing 1988: 93-95). It is these deficits in the recognition and understanding of emotions in others that lead to an impoverishment in the ability of individuals with autism to empathise with others. In a study designed to assess the response of individuals with autism to a person feigning distress, Sigman et al. (1992) found a striking absence of expressed concern from the participants. While only the triad of impairments of social interaction are argued to be the necessary symptoms for diagnosis, there are other behavioural traits that are commonly observed in individuals with autism. A particularly common characteristic is repetitive activities such as the following: a fixed bodily posture; motor stereotypies such as rocking, flicking of fingers or walking on tip-toe; intense attachment to objects or engrossment in either music or the repetitive arrangement of objects; ritualistic behaviour in regard to routines such as meal times or journeys; and, for higher functioning individuals, the accumulation of facts of singular interests such as railway timetables or extreme preoccupation with particular books which are frequently reread (Happé 1994: 18; Wing 1988: 95). Wing (1988) commented that although repetitive behaviours are highly likely to be present in individuals with autism, they are not considered a diagnostic criterion since they may also be observed in young typically developing children as well as children with severe intellectual disabilities. Further characteristics often observed in individuals with autism include variable motor abilities: awkwardness of gait and posture are fairly consistent but while some may demonstrate little skill in gross motor abilities, others are unusually agile. Similarly, some individuals may have unerring fine motor skills while others are clumsy. Unusual responses to sensory stimuli as originally recognized by Kanner (1943) are often observed. These include ignoring sounds or oversensitivity towards them, indifference to tactile stimuli such as temperature, pain and even gentle touch and absorption with visual stimuli such as shiny or spinning objects. However, Wing (1988: 97) indicated that these types of responses are more prevalent in young children with autism and those who also have severe intellectual disabilities. The extensive research into the behavioural manifestations of autism which has followed Kanner’s original publication has provided much information in regard to which features of the syndrome are to be considered primary and which features are usually associated but not considered central to the disorder. The groundbreaking work of Wing and Gould (1978; 1979) reinforced the identification of autism as a syndrome as well as providing clear evidence of social impairment as a primary indicator from among the many features observed during the course of clinical research. Moreover, the

Autism: The current perspective

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concept of the autistic spectrum neatly captures the variation of behaviours and abilities within the syndrome which are outside Kanner’s autism. 2.2. Autism and aetiology Despite the significant advances in research over the last few decades, the exact cause of autism remains, as yet, unknown. While many theories have been postulated, there is much evidence to indicate a neurological origin of the disorder. The advent of highly sophisticated neural imaging technology has produced some promising leads, but research attempting to locate the specific site at which brain damage occurs is inconclusive. Nonetheless, much has been learned about the causative agents such as birth trauma and genetic abnormalities which lead to the onset of autism via a common neural pathway which remains unidentified. The fact that the boundaries of what constitutes autism are somewhat fuzzy means that epidemiological information tends to vary. Early surveys projected the population distribution to be 4 to 5 people per 10,000 (Lotter 1966). These surveys were based on Kanner’s original description which is now usually considered “classic” autism. More recent studies place the figure at 10 in 10,000 (Bryson, Clark, and Smith 1988), 20 in 10,000 (Wing and Gould 1979), or even higher (Ehlers and Gillberg 1993). Bryson (1997) attributed this increase in numbers to the broader conceptualization of autism recognized as the autistic spectrum. A survey of studies published since 1987 yields figures for the current prevalence of autism at 10 in 10,000 and 16 in 10,000, with the midpoint of 13 in 10,000 chosen as the representative rate (Fombonne 2005). However, a study on data collected in 2006 puts the figure at 90 in 10,000 (Centers for Disease Control and Prevention 2009). In Australia, the prevalence rate is estimated to be 9.5 to 10 per 10,000 children (Tonge and Brereton 2005), or as high as 62.5 per 10,000 for children aged between six and twelve (MacDermott et al. 2006). The figures outlining the ratio of males to females in the autistic population are also somewhat variable. For classic autism, the ratio is 3:1 or 4:1, the higher figure relating to males (Lotter 1966; Wing and Gould 1979). However, more broadly defined autism yields different figures depending on intellectual ability. Individuals with severe cognitive impairment show a male to female ratio of 2:1, while more cognitively able individuals have a ratio of 3:1 or 4:1 (Bryson 1997: 42). Current figures indicate a male to female ratio of 4.3:1 (Fombonne 2005) or up to more than six boys for every girl (CDC 2009). In regard to the issue of intellectual disability and autism, current figures reveal that 29.6 per cent of

24

What is autism?

individuals with autism do not have intellectual impairment, while 29.3 per cent have a mild to moderate intellectual impairment and 38.5 per cent of individuals are severely to profoundly intellectually disabled (Fombonne 2005). Although Kanner and Asperger originally argued against the theory that autism was a result of environmental conditioning, explanations for the disorder which appeared shortly after the original studies described autism in psychogenic terms. A popular theory dubbed “the refrigerator mother” theory suggested that children become autistic in response to an unloving and threatening environment (Bettelheim 1967). However, evidence from children who have experienced horrific social deprivation and yet who did not develop autism strongly counter this theory (Frith 1989: 34-35). Kanner, himself, contemplated the possibility that the autistic features he observed in the parents of the children he studied contributed to their condition. It is likely that his influence promoted the longevity of this otherwise unfounded theory. A further impetus for the “refrigerator mother theory” came from intriguing statistics which revealed a large percentage of children with autism came from a high socio-economic status. This apparent connection between autism and the children of professional, intellectual parents only served to enhance the conception of the mother of a child with autism as an emotionally detached, intellectual woman whose energies were focussed on her career, and not her family. However, later studies have revealed that there is no direct link between autism and social class (Schopler, Andrews, and Strupp 1979; Wing 1980). While the precise pathophysiology responsible for autism is still being investigated, there is no doubt that the syndrome has neurological origins. Some of the earliest evidence comes from the fact that approximately onethird of individuals with autism develop epilepsy during adolescence (Gillberg and Steffenburg 1987; Tuchman and Rapin 2002) and, as noted earlier, intellectual disabilities accompany the disorder in up to three quarters of the autistic population (Fombonne 2005; Happé 1994). More is known about the types of conditions that can lead to the onset of autism. These include genetic defects, chromosome abnormalities such as Fragile-X syndrome, prenatal or perinatal brain damage, viral infections such as rubella and herpes and immune dysfunction (Frith 1989: 77-80). It is hypothesized that a common physiological pathology which has its origins at the level of DNA or its transcription for brain development, results in autism (Minshew et al. 2005; Minshew and Williams 2007). Studies examining the structure of the brain have identified a paradox in the development of brain growth in individuals with autism: while there is evidence of excessive growth involving the

Autism: The current perspective

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cerebrum (both grey and white matter), general increased brain weight and larger than normal head circumference, there is also evidence of impoverished growth in the cerebellum (an area of the brain which governs motor skills, cognitive processes such as memory, concept formation and language generation) and stunted growth of neurons in the limbic system (a complex of centres in the brain which processes the emotional aspects of behaviour) (Minshew, Sweeney, and Bauman 1997: 344). The advent of more advanced technology such as magnetic resonance imaging (MRI) and functional MRI (fMRI) has allowed for a greater understanding of how brain development is affected and the resulting cognitive profile of autism. Identifying the neuropathology unique to autism and its role in producing the behavioural abnormalities discussed above is, indeed, a difficult challenge. This is particularly the case when the behavioural features of autism centre on higher cognitive functions as captured in the triad of impairments. Psychological theories which attempt to explain the impairments of socialization, communication and imagination provide clues as to which functions of the brain might be lost and, hence, contribute to the investigations into the pathology of autism.

2.3. Autism and cognitive abilities While the variation in behavioural features observed in autism is also true for cognitive abilities, a general cognitive profile for the syndrome is well documented. Within this profile another frequently reported phenomenon in regard to cognitive abilities is noted: individuals with autism often show remarkable rote memory and ability in constructional skills. More rarely, these skills produce extraordinary expertise in areas such as drawing, piano playing, and mechanical design. These exceptional skills are what Kanner called “islets of ability”. Investigations into the cognitive abilities of individuals with autism aim to provide answers for the uneven results obtained through IQ-tests as well as to ascertain the deficit or deficits which lead to the behavioral impairments discussed above. A number of theories have been postulated to account for the pattern of cognitive abilities found in autism. However, none of these theories offer a conclusive explanation, despite some comprehensive experimental studies. The validity of IQ-test results as an indicator of the abilities of individuals with autism has been questioned in light of the variation in performance across a range of tests which is typically observed. In typical development,

26

What is autism?

individuals display an even level of performance when tested, whether they are of high or of low intelligence. In contrast, individuals with autism achieve high scores on some tests but low scores on others, as well as experiencing difficulties completing some tasks. However, studies which have tested the IQ of children with autism from childhood to adolescence have found that the original results they obtained remained relatively constant (Freeman et al. 1991; Lockyer and Rutter 1970). Therefore, the fluctuating results of IQ-tests are more indicative of the difficulties associated with the syndrome than the actual test procedures. Nonetheless, IQ-tests such as the Wechsler Intelligence Scale for Children (WISC) must form only one element of a broad assessment (to be discussed below) if a more comprehensive picture of the individual under examination is to be achieved. The WISC is most commonly used to assess the intelligence levels of children with autism. It consists of a series of subtests which examine visuospatial abilities as well as verbal abilities. While the majority of children with autism fall into the low IQ range, their performance IQ is usually greater than their verbal IQ (Green et al. 1995; Joseph, Tager-Flusberg, and Lord 2002). Tasks in which individuals with autism excel include the Block Design test (WISC), illustrated in Figure 1, which requires participants to reproduce an abstract pattern with a set of small cubes during a fixed time limit. As Frith (1989) pointed out, the achievement of individuals with autism on tasks of perceptual organization and perceptual-motor integration is remarkable inasmuch as their performance levels are average or above average according to normal development, and yet their test scores on most WISC subtests are below average. In contrast, children with autism tend to perform most poorly on tasks which require a verbal response. While short-term memory tasks yield higher results, the Comprehension subtest (WISC) in which participants are required to answer questions about social knowledge is one which children with autism find particularly challenging (Green et al. 1995: 15). Nonetheless, the poor performance on communication tasks cannot simply be explained in terms of language impairment: studies comparing the performance levels of children with autism in relation to children with specific developmental receptive language disorder found that the weakness in verbal competence observable in children with autism is not attributable to a language disorder (Bartak, Rutter, and Cox 1975). Moreover, children with autism are well able to articulate information on topics they know well when questioned (Frith 1989: 88). The cognitive profile obtained for individuals with autism is strongly indicative of a neurological disorder and, although there is heterogeneity within the autistic population, the pattern is unique to the syndrome.

Autism: The current perspective

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Figure 1. Example from the Block Design Test Reproduced with kind permission from U. Frith (2003) Autism: Explaining the Enigma, 2nd Edition (Oxford: Blackwell), p.156

One of the major psychological theories of autism to emerge over the last two decades as an explanation for the uneven cognitive development of individuals with autism is the claim that they lack a theory of mind. The phrase “theory of mind” originated from the work of Premack and Woodruff (1978) and is defined as the ability to conceive of mental states or, to attribute thoughts and emotions to others. This capacity to recognize that others have mental states different from our own is known as metarepresentation. In typical development, by the time a child reaches two years of age he or she is capable of both primary representations (perception of the physical world) and of metarepresentations (representations of representations) which allows for the emergence of pretend play (Leslie 1987). It has been argued that the lack of pretend play in children with autism indicates a metarepresentational deficit, independent of IQ, which is a primary cognitive deficit responsible for the social impairment of the syndrome (Baron-Cohen, Leslie and Frith 1985;

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What is autism?

Leslie and Frith 1988). However, later research has revealed that the difficulties experienced by children with autism cannot be attributed to a metarepresentational deficit, per se. Studies have shown that children with autism can engage in pretend play, either when prompted or even spontaneously (Jarrold 2003; Jarrold, Boucher, and Smith 1996; Lewis and Boucher 1988; Wing and Gould 1979). Moreover, children with autism demonstrate intact abilities for non-mentalistic tasks such as the false photograph task in which an image in a photograph does not correspond to a real world state (Leekam and Perner 1991; Leslie and Thaiss 1992). Consequently, the proposed metarepresentational deficit was refined to encompass only difficulties with mentalistic representations such as the propositional attitude “he thinks x” (Leslie and Thaiss 1992). There has been much research into the nature of the theory of mind deficit in autism. Baron-Cohen, Leslie, and Frith (1985; 1986) conducted the first studies assessing theory of mind abilities in children with autism. They tested the ability of children with autism to successfully complete false belief tasks compared with control groups of normally developing children and children with Down Syndrome. In brief, the false belief task consisted of a short scenario illustrated in Figure 2 in which the children observed one doll, called Sally, place a marble in her basket before exiting, while the other doll (Anne) then removed the marble from the basket and placed it in her box. The test of false belief was in the question asked of each participant “Where will Sally look for her marble?”, the correct response being “in the basket” (BaronCohen, Leslie and Frith 1985). Baron-Cohen et al. found that the children with autism could not correctly predict a character’s actions based on the ability to represent mental states. That is, they were unable to recognize that Sally would look for her marble in the basket because that was where she believed it to be, being unaware of the real state of events. Later studies using a range of false belief tasks have produced the same results: Baron-Cohen, Leslie and Frith (1986) found that children with autism had significant difficulty in completing picture sequencing tasks which required the ability to infer mental states. In this study, the participants were required to arrange four pictures in their logical sequence and relate the story depicted to the experimenter. While the children with autism performed well on tasks which required an understanding of mechanical criteria (e.g. a balloon flies towards a tree and bursts on the branches) and behavioural criteria (e.g. a girl walks to a shop, enters, and buys some lollies) their performance level dropped considerably on tasks which required an understanding of intentional criteria (e.g. a boy buys lollies, leaves the shop, the lollies fall out of the bag, and the boy is shocked when he sees they are gone).

Autism: The current perspective

Figure 2. The Sally-Anne task Reproduced with kind permission from U. Frith (2003) Autism: Explaining the Enigma, 2nd Edition (Oxford: Blackwell), p.83

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What is autism?

Leslie and Frith (1988) tested the ability of children with autism to attribute mental states to real people. The task was a false belief task constructed on the basis of the Sally-Anne paradigm, but with the experimenters as the protagonists. Once again, children with autism had difficulty in recognising that the person who was unaware of the transfer of the object from one location to another would look for it in the original place. To ensure that the apparent theory of mind deficit in children with autism was not due to an unwillingness of the participants to attribute false beliefs to adult experimenters or wooden dolls, Perner et al. (1989) tested the ability of these children to recognize their own false belief. The participants were shown a closed Smarties tube and asked to guess what was inside. After answering “Smarties” or something similar, the tube was opened to reveal a pencil. When the children with autism were asked what they thought a new child who had not been tested would think was in the container, the majority of them answered “a pencil” even though they remembered that they originally thought the tube contained Smarties. Still further studies have found that children with autism have difficulty with mental state words such as “think” and “believe” (Baron-Cohen et al. 1994; Tager-Flusberg 1992), understanding deception, including lies (Leekam and Prior 1994; Sodian 1991) and understanding jokes and irony (Happé 1994; Leekam and Prior 1994). The broad range of studies testing the understanding of mental states presents strong evidence of a theory of mind deficit in autism. However, modifications to the theory have been made in light of evidence that some individuals demonstrate evidence of a theory of mind: while the majority of individuals with autism fail the first-order false belief tasks (inferring what another person is thinking) there are some who do pass. Nonetheless, these individuals frequently fail second-order false belief tasks (understanding what one character thinks another character thinks) and even the very small minority who pass these still reveal some abnormalities of theory of mind (Baron-Cohen and Swettenham 1997: 883). While the theory of mind deficit does present a powerful explanation for the social impairments manifest in autism, it cannot account for other behavioural features such as repetitive movements and perseverative interests. Another theory presented as a primary cognitive deficit in autism is executive function. The term “executive function” denotes the cognitive construct used to describe behaviour believed to be moderated by the frontal lobes. Some of the behaviours covered by executive function include planning, controlling impulses, restraint of incorrect responses, flexibility of thought and action – all purported to share the capacity for disengagement from an immediate context in favour of guidance by internal representations

Autism: The current perspective

31

such as plans or goals (Ozonoff 1995). The application of executive function theories to autism arose out of the similarity in behaviour observed between individuals who had experienced frontal lobe damage and individuals with autism. Thus, it is contended that typical behavioural features such as insistence on sameness, perseverative behaviours including narrow interests or motor stereotypies, impulsiveness and intense focus on detail are evidence to suggest executive function as a primary cognitive deficit in individuals with autism. Empirical evidence in support of this theory was sought through studies which tested the abilities of high-functioning adult males with autism using the Wisconsin Card Sorting Test (WCST), which requires the participant to flexibly shift card-sorting strategies (Rumsey 1985; Rumsey and Hamburger 1988; 1990). In this test, the participant is required to sort a deck of cards which have the following features: each card has a set of shapes (four different types) ranging in number from one to four which are uniformly depicted on each card in one of four colours. Four stimulus cards which have no features in common are placed in front of the participant who must deduce the correct principle for sorting the deck from the examiner’s verbal feedback (e.g. “right”, “wrong”). Once a criterion is reached, that is, the participant has discovered the correct principle, the examiner changes the principle without informing the participant. All three studies consistently found that the individuals with autism they tested performed less well than the matched control groups of normal males (Rumsey 1985; Rumsey and Hamburger 1988) and severely dyslexic males (Rumsey and Hamburger 1990) on tasks specific to executive function skills. Studies testing children with autism using WCST and comprehensive test batteries examining executive function, theory of mind, emotional perception, verbal memory and spatial abilities found that deficits in executive function were predominant (Ozonoff, Pennington, and Rogers 1991; Prior and Hoffman 1990). Further research into the possibility of executive function deficits in autism tested the ability of individuals with autism to perform the task demands of The Tower of Hanoi, illustrated in Figure 3. This task requires the participant to move disks of varying sizes which are placed on three pegs to reproduce the design of a display configuration, but with restrictions: the participant must not place a large disk on top of a smaller disk and the task must be completed in the smallest number of moves possible (Ozonoff 1995: 206). The Tower of Hanoi tests the ability to strategize which is believed to be mediated by the frontal lobes. Ozonoff, Pennington and Rogers (1991) found that the participants with autism were significantly less able to complete the task than the matched control group of non-autistic individuals with various intellectual

32

What is autism?

disabilities. Therefore, they concluded that executive function deficits were a primary cognitive deficit and, hence, a reliable indicator of autism. Further studies have found evidence of executive function deficits in children with autism (e.g. Corbett et al. 2009; Geurts et al. 2004; Goldberg et al. 2005) however, the status of executive function deficits as a core feature of autism has been questioned (Hill 2004).

Figure 3. Tower of Hanoi (three-disc version) Illustration courtesy of Katherine Heyward.

Similar to the theory of mind deficit account of the cognitive abilities of individuals with autism, the executive function deficit theory has both strengths and limitations. While there is certainly sufficient evidence to validate an executive function deficit in autism, this type of dysfunction is by no means unique to autism. Patients with frontal lobe damage are not autistic, despite the similarity of features and other clinical disorders such as schizophrenia, Obsessive-Compulsive Disorder, Tourette’s Syndrome and attention deficit hyperactivity disorder (ADHD) also show executive function deficits (Baron-Cohen and Swettenham 1997; Corbett et al. 2009; Ozonoff 1995). Moreover, tasks which an executive dysfunction theory would predict children with autism should fail produce opposite results: as noted above, children with autism pass false photograph tasks which require the ability to form mental representations in order to accurately predict where an object will be located in a photograph in the face of conflicting contextual evidence (Leekam and Perner 1991; Leslie and Thaiss 1992). Executive function deficit in its strong form appears untenable, however, empirical evidence shows that it can account for a number of behavioural features typically observed in individuals with autism such as motor stereotypies. Baron-Cohen and Swettenham (1997) suggested that theory of mind deficit and executive function deficit accounts of autism are not mutually exclusive. There is evidence to justify the separateness of theories and co-occurrence of these

Autism: The current perspective

33

cognitive deficits would provide a far more powerful explanatory tool than is currently available. A third cognitive theory involves what is known as “central coherence”. Frith (1989) has proposed a theory of impaired central coherence to account for the pattern of cognitive abilities observed in individuals with autism. She defined central coherence as a high-level cognitive force that draws together large amounts of information into context, or gestalt and suggests that this high-level central cohesive force is impaired in individuals with autism (1989: 98). Frith argued that this type of cognitive impairment seen as a primary deficit of autism is consistent with the pattern of IQ-test results discussed above. Evidence for a central coherence deficit was discovered somewhat unexpectedly. Shah and Frith (1983) tested the ability of children with autism to perform the Embedded Figures test. This task involves locating a small target shape embedded in a larger drawing made up of many lines. They found that their sample of children scored well above what would be expected for their mental age. This is consistent with the hypothesis that weak central coherence would produce non-holistic perceptual processing, thereby reducing the obscuring effect of the larger picture on the target shape. Further support for the central coherence account of autism came from an adapted version of the WISC Block Design task (see Figure 1). Based on the well documented abilities on this task of individuals with autism, Shah and Frith (1993) predicted that the performance of normally developing children could be improved if the target design was segmented to match the blocks used for the task. The results revealed a marked improvement in the ability of both the normally developing and intellectually disabled control groups, while the performance of the children with autism remained constant. Although the theory of a central coherence impairment offers a neat explanation for some of the strengths and weaknesses in the cognitive abilities of individuals with autism, studies have offered varying support. While some studies have shown evidence of deficits in global processing (e.g. Happé 1997; Happé, Briskman and Frith 2003; Jolliffe and Baron-Cohen 1999) other studies show no difference in task performance between individuals with autism and control groups (e.g. Brian and Bryson 1996; Pring and Hermelin 1993; Ropar and Mitchell 1999). Baron-Cohen and Swettenham (1997) noted that as with theory of mind deficit and executive function deficit, a strong version of central coherence must be discounted. The theory does potentially explain some aspects of cognitive ability which are beyond the scope of the other two theories. However, researchers have argued that a specific difficulty in processing complex verbal stimuli rather than a general difficulty in macro-

34

What is autism?

level processing can account for the variation in study results and is consistent with the cognitive profile of autism (Brian and Bryson 1996; López and Leekam 2003). Despite the substantial research into the cognitive profile of individuals with autism undertaken in recent years, many questions remain unanswered. While much is known about the pattern of cognitive abilities manifest in the disorder, there is no single cognitive deficit theory which can simultaneously account for the cognitive profile and accommodate the variation in impairment. Moreover, there are no conclusive links between proposed cognitive deficits and neural pathology, despite promising studies using functional neuroimaging techniques during cognitive tasks (Castelli et al. 2002; Koshino et al. 2005; Lainhart 2006; Schultz 2005). Further investigations into the theory of mind deficit, executive function and central coherence theories are necessary to clearly define what is unique to autism.

2.4. Autism and language Language impairment as a cognitive feature of autism has been of interest to researchers since the recognition of the disorder as an independent syndrome. Early descriptions concentrated on the overtly atypical features such as echolalia, or the repetition of words or phrases uttered by another. Language impairment in autism and its status as a primary deficit of autism was closely investigated (Rutter 1970; Schopler and Mesibov 1985). While this theory was ultimately dismissed, language difficulties are still recognized as an important issue both clinically and theoretically. Verbal children with autism typically experience delayed onset of speech and developmental delay during the acquisition process. Little is known about the early acquisition of speech in children with autism since diagnosis of the disorder in children younger than three or four years of age has only become more common in the last ten to fifteen years (Moore and Goodson 2003; Klin et al. 2004). However, communication difficulties have been reported in very young children (Lord and Paul 1997; Mitchell et al. 2006). A study assessing the expressive and receptive language ages of two-year-old children who showed strong signs of autism found that their verbal ages were less than nine months – much lower than the age levels of their nonverbal skills – and their language development continued to be delayed (Lord et al. 1996). The loss of words in around a quarter of children with autism at the age of twelve or eighteen months is a profile unique to autism which is a gradual process and

Autism: The current perspective

35

coincides with loss in social skills (Kurita 1985; Lord, Schulman, and Di Lavore 2004). Although the onset of language is delayed in children with autism, studies have revealed that the acquisition of phonemes follows that of normal development (Kjelgaard and Tager-Flusberg 2001). Bartolucci et al. (1976) found that the distribution of phoneme frequency and phonological error types of their participants with autism was comparable to their matched control group of participants with intellectual disabilities. Other researchers have argued against the possibility that children with autism have a deficit in this area of language (Bartak, Rutter and Cox 1975; Tager-Flusberg 1981a). However, Shriberg et al. (2001) found that a third of speakers with highfunctioning autism or Asperger Syndrome continued to experience articulation difficulties into adulthood. Other aspects of speech production such as prosody are usually atypical in autism. Prosodic impairments in speech quality, rhythm, stress and intonation are frequently documented features of the language of individuals with autism which usually persist into adulthood (Tager-Flusberg 1989). It is argued that these features cannot be explained solely in context of motor or perceptual deficits (Lord and Paul 1997: 210). Rather, it may be that, similar to the absence of nonverbal features such as gesture discussed in section 2.1, the deficits in suprasegmental features of autistic speech are a linguistic reflection of the social communication impairments of the disorder. The acquisition of syntactic and morphological processes in children with autism also appears concordant with normal development. A longitudinal study comparing the syntactic development of children with autism and children with Down syndrome found no significant difference in the patterns of acquisition between the groups or with the pattern of normal development reported in the literature (Tager-Flusberg et al. 1990). However, a follow-up study using the same data found that analysis of grammatical development using the Index of Productive Syntax (IPSyn) (Scarborough 1990) revealed that children with autism rely on a narrower range of syntactic constructions, including question types (Scarborough et al. 1991). As with the acquisition of phonological processes, children with autism exhibit a delay in their syntactic and morphological development (Walenski, Tager-Flusberg & Ullman 2006) and studies have found that the delay evident in children with autism is often more severe than non-autistic intellectually disabled children of the same verbal mental age (Wing and Gould 1979). The acquisition of grammatical morphemes is argued to be difficult for children with autism. Verb morphemes encoding person, tense and aspect as well as determiners and auxiliaries are likely to be omitted (Bartolucci, Pierce, and Streiner 1980) and past tense

36

What is autism?

morphemes prove the most problematic (Bartolucci and Albers 1974; Roberts, Rice, and Tager-Flusberg 2004; Tager-Flusberg 1989). While the development of grammatical structures proceeds normally in children with autism, a particularly prominent aspect of language impairment in autism is echolalia. This may be immediate, as in the parrot-like responses observed by Kanner (1943) or delayed. Not all children engage in echolalia, nor is it unique to the syndrome. For those children with autism who do echo, they are most likely to have difficulty producing spontaneous speech (Loveland and Tunali-Kotoski 1997: 287). While all forms of echolalia were originally considered to be dysfunctional speech behaviour, more recent research has found that it can serve a communicative function. Prizant and Duchan (1981) assessed the role of echolalia in the productive language of children and found that although some echolalic speech (such as the repetition of advertising jingles) played no constructive role, often, immediate echolalia served a communicative function which conformed to the following seven headings: 1. turn-taking, 2. assertions (often accompanied by demonstrative gestures), 3. affirmative answers, 4. requests, 5. non-focussed utterances (often produced during states of high arousal such as fear with no communicative intent) 6. rehearsal to aid processing, and, 7. self-regulation (utterance simultaneous with motor action) (Prizant 1983: 67). Delayed echolalia may also serve these functions, and a number of studies examined the role of both immediate and delayed echolalia in the process of language acquisition. In their analysis of the bedtime soliloquies of an eight-year-old child with autism, Baltaxe and Simmons (1977) found many examples of delayed echolalia which they suggested were being used as an acquisition strategy not unlike the behaviour sometimes observed in much younger normally developing children. That is, the stored utterances were used as a means of analysing linguistic forms the child was in the process of acquiring. However, Tager-Flusberg and Calkins (1990) found that the echolalic utterances of the children they observed for twelve months were no more grammatically complex, nor longer than their spontaneous speech. They cautioned that although echolalia may provide a means of exercising conversational skills, it is not clear that it facilitates grammatical development. The current perspective on echolalia in autism is that, for many children, it can be seen as a linguistic platform through which more creative, rule-governed language may emerge (Prizant et al. 1997: 575). In contrast to expressive language, the most significant impairments in the language of individuals with autism with productive speech are in language comprehension and pragmatics. While syntactic expression is argued to remain intact, understanding of agent/patient relations and transitivity is

Autism: The current perspective

37

limited and there is a marked reliance on word order for the interpretation of sentences (Paul, Fischer, and Cohen 1988; Prior and Hall 1979). Further difficulties are observable in the use of deictic forms, including articles and past tense marking. Similarly, the reversal of pronouns is a common phenomenon. While pronoun reversal is also a documented feature of very young normally developing children, it is prolonged in children with autism and is often in contrast with their general language abilities (Loveland and Tunali-Kotoski 1997: 288). Studies have suggested that this difficulty with pronouns in children with autism occurs most prolifically in situations when they have difficulty identifying the social roles of themselves or others (Lee, Hobson and Chiat 1994; Loveland and Landry 1986). The striking impairment in communicative abilities of individuals with autism is well documented: although a desire to communicate is often observed, individuals with autism are severely limited in their ability to engage in acts of communication that involve joint reference (Lord and Paul 1997: 215). Thus, judging how much or how little information the hearer requires is difficult and individuals with autism often make irrelevant remarks or pursue a topic of personal interest, irrespective of the response of the hearer. Studies in early language development revealed that the comprehension of words was delayed in comparison to word production in children with autism below the age of three (Charman et al. 2003; Paul et al. 2007). However, language comprehension abilities are more equal to language production skills as children become older (Jarrold, Boucher, and Russell 1997; Kjelgaard and Tager-Flusberg 2001). The process of lexical acquisition in autism is a widely debated issue. Some researchers have argued that a categorization deficit, which inhibits lexical acquisition much beyond a perceptual level, forms part of the language impairment of the disorder (Klinger and Dawson 1995; Shulman, Yirmiya, and Greenbaum 1995). Conversely, other researchers have concluded that there is no deficit of conceptual organization, but that the impairment is found in the limited ability of children with autism to use this information at a functional level (Tager-Flusberg 1985a; 1985b; Rapin 1996). The debate regarding the presence or absence of a categorization deficit is centred on the acquisition of object labels, while studies on general lexical development focus on issues such as form class distribution (Tager-Flusberg et al. 1990; Williams 1993). I will discuss the development of verbs and prepositions in autism alongside the results of the present study in chapters three and four. A particularly relevant issue in the context of semantic development in autism is the premise from research in typical development that theory of mind skills play a critical role in lexical development. Many researchers

38

What is autism?

investigating the linguistic abilities of children with autism have argued that their limited capacity for theory of mind is evident in the paucity of terms in their general language which refer to psychological states (Baron-Cohen 1991; Eskes, Bryson and McCormick 1990; Happé 1995; Hobson 1986; TagerFlusberg 1992; 1993). More specifically, such researchers have argued that these children’s limited ability with theory of mind does not affect language acquisition per se, but is most readily observed in aspects of communication which require social cognition such as talking about thoughts and feelings, declarative statements and the construction of narratives (Happé 1993; TagerFlusberg 1997). However, the studies in typical development point to a more intricate relationship between lexical development and theory of mind. A number of studies have considered the impact of poor joint attention skills on general language development in children with autism. Loveland and Landry (1986) found correlations between the joint attention deficit in children with autism and their language development indicated by measures of their spontaneous communicative behaviour and pronoun use. That is, the stronger the absence of attention-directing gestures such as pointing or showing, and spontaneous communicative behaviour, the more their language development was inhibited. Previous research has also established that preschool age children with autism who are more adept in the use of social nonverbal modes of communication also demonstrate greater development of language comprehension earlier than children who have a deficit in joint attention behaviours (Charman et al. 2003; Lord and Schopler 1989; Mundy, Sigman and Kasari 1990; Sigman and Ruskin 1999). Leekam and colleagues found that dyadic orienting and joint attention skills in preschool-aged children (Leekam, López, and Moore 2000; Leekam and Ramsden 2006) and older children with autism (Leekam, Hunnisett, and Moore 1998) were related to language abilities. In regard to lexical development, Rollins (1999) found that joint attention skills in children with autism at the early stages of language acquisition have a positive effect on vocabulary growth. Similarly, a study testing the theory of mind abilities of children and adolescents with autism aged between six and eighteen years revealed that only individuals with a high verbal mental age as measured by the British Picture Vocabulary Scale were able to pass theory of mind tasks (Happé 1995). Sparrevohn and Howie (1995) also found that verbal ability was an important factor in the performance of children with autism on theory of mind tasks. Frith and Happé (1994) acknowledged that a theory of mind deficit may have a negative impact on word learning by interfering with the development of nonverbal behaviours such as joint attention, reference and ostension.

Diagnosis and assessment

39

A prediction of the social-pragmatic approach to word learning is that children with autism with weak theory of mind skills should experience significant problems in lexical acquisition. Moreover, a limited ability to attend to, and process communicative intent may lead to mapping errors not observed in typical development. In point of fact, there is much documented evidence of purely associative learning of the kind discussed in the introduction in the language of children with autism (Kanner 1943; Grandin 1995; Tager-Flusberg 1997). Kanner (1943; 1973) described a young boy with autism who referred to saucepans as “peter eater” because as a two-year-old, he was listening to his mother recite the rhyme “Peter, Peter, pumpkin eater” when she dropped a saucepan. Baron-Cohen, Baldwin, and Crowson (1997) investigated the ability of children with autism who had a verbal mental age of two to infer the communicative intent of a speaker in a novel word learning scenario. Using Baldwin’s (1993) methodology, Baron-Cohen et al. found the children with autism did not consistently use the experimenter’s direction of gaze to infer whether the experimenter was looking at the toy the child was holding, or the toy the experimenter was holding when a novel label was uttered. Consequently, the children with autism produced many mapping errors. The presence of associative learning in a population group with known difficulties in social communication suggests that theory of mind abilities do play a pivotal role in the process of lexical acquisition. 3. Diagnosis and assessment The heterogeneous nature of autism has created difficulties in the past in regard to recognition as a separate syndrome, the construction of an adequate definition of the disorder and, consequently, the establishment of satisfactory diagnostic criteria. Inflexible definitions which allow no scope for variation in manifestations of the features presented imply that only the most severe cases can be considered true examples of autism. More expansive definitions need to take account of other pervasive developmental disorders which possess strong similarities with autism but are clinically distinct. Both Childhood Disintegrative Disorder (CDD) and Rett’s syndrome share many diagnostic features of autism. These include: impaired social skills, limited expressive vocabulary accompanied by pragmatic deficits, stereotyped behaviours, and resistance to change (Van Acker 1997; Volkmar et al. 1997). However, CDD differs from autism in its onset – individuals with CDD demonstrate normal development for the first two years before onset. Rett’s syndrome has been diagnosed exclusively (to date) in females and, unlike autism, the features of

40

What is autism?

the disorder also include regression of motor skills, a distinct respiratory pattern and, similar to CDD, normal prenatal and perinatal periods. At present, autism is diagnosed on the basis of behavioural features. It is likely that, as more is learnt about the pathogenic origins of the disorder, the classification of autism will ultimately change. However until such time, the development of internationally recognized diagnostic criteria has created a more unified understanding of the disorder for clinicians and researchers alike. There are two current diagnostic classifications of autism. One is contained within the Diagnostic and Statistical Manual of Mental Disorders (DSM-IVTR) (American Psychiatric Association 2000) and the other in the International Classification of Diseases, 10th edition (ICD-10) (World Health Organization 1992; 1993). Unlike earlier revisions, the production of these versions was a collaborative effort resulting in two diagnostic systems more strongly convergent which has led to internationally accepted guidelines. The diagnostic criteria for autism include: abnormal or delayed development (with onset before the age of three) in the areas of social interaction, language use in social communication and symbolic play. Further criteria are: qualitative impairment, or abnormalities, in reciprocal social interaction in at least two of the four areas of 1. nonverbal behaviours (eye-toeye gaze, facial expression, body postures gestures relating to social communication), 2. peer relationships, 3. socio-emotional reciprocity and 4. the sharing of interests, enjoyment or achievements with other people; qualitative impairment or abnormality in at least one of the four areas of 1. spoken language (not accompanied by compensatory gestures or mime), 2. initiating and sustaining conversational interaction, 3. stereotyped and repetitive mannerisms, and 4. symbolic or imaginative play; and, restricted, repetitive and stereotyped patterns of behaviour manifest in at least one of the four areas of 1. preoccupation with stereotyped and restricted patterns of interest and activities, 2. insistence on sameness in routines and rituals, 3. motor mannerisms (e.g. hand flapping, or whole-body movements), and 4. preoccupation with parts or non-functional elements (e.g. odour) of objects. A final criterion is that the atypical behaviours are not better accounted for by other types of pervasive developmental disorders (American Psychiatric Association 2000; World Health Organistion 1993). Comparison with the diagnostic criteria of ICD-10 reveals strong similarities as well as some differences. In particular, the system from DSM-IV is a single definition for both clinicians and researchers while ICD-10 is divided into one set of criteria for research (World Health Organization 1993) and another set for clinical practice (World Health Organization 1992). While the respective definitions do not differ in their diagnostic criteria, the ICD-10

Diagnosis and assessment

41

description of autism for research is more expansive. Both ICD-10 and DSMIV include disorders suggestive of autism but which do not meet the diagnostic criteria, listing them under the broader category of Pervasive Development Disorders as Atypical Autism and Pervasive Development Disorder – Not Otherwise Specified, respectively. Similarly, Asperger Syndrome is not included under autism in either classification, but is listed as a separate category of Pervasive Development Disorders. Categorical diagnostic systems such as DSM-IV and ICD-10 provide an extremely useful function, offering a level of continuity for both research and clinical settings and facilitating understanding of an individual’s needs. However, overuse of categorical labels can lead to promotion of the disorder above the individual and the connotative effects of labelling have the potential for negative consequences (Akerley 1988: 63). The importance of recognising diagnostic classification as but one aspect of a more comprehensive diagnostic process is well acknowledged (Schopler and Mesibov 1988). Volkmar, Klin, and Cohen (1997) asserted that diagnosis and assessment of an individual with autism should consist of the following components: the provision of diagnosis using DSM-IV or ICD-10; a full description of the individual; an account of the development and progression of symptoms, including personal history and social situation; a careful analysis of the areas of both competence and difficulties of the individual; documentation of previous treatments and individual progress; delineation of individual aetiology where possible, and; since autism is a developmental disorder, ongoing observation of the individual in recognition that diagnosis and assessment is a dynamic process (1997: 6). The variation in manifestation of autism requires a unifying diagnostic system and yet necessitates a detailed and broad-based approach to ensure an adequate response to the needs of each individual. A number of measures exist which were designed for the purpose of autism diagnosis. One such measure is the Autism Diagnostic Interview – Revised (ADI-R) which is based on the diagnostic criteria of the DSM-IV and ICD-10. The most recent version of ADI-R is a semi-structured interview with three sub-scales of social reciprocity, communication and restricted, repetitive behaviours which can be completed in approximately two hours and is administered by an experienced interviewer (Le Couteur, Lord, and Rutter 2003). Another assessment tool in the interview format is the Diagnostic Interview for Social and Communication Disorders (DISCO) which is in its ninth version (Wing et al. 2002). The intent behind the DISCO is not to provide a diagnostic classification, but to create a profile of behaviours related to autism to assist clinicians in assessing a child’s individual needs. The interviewer asks a series of questions designed to elicit behavioural

42

What is autism?

descriptions in the areas of social interaction, communication, imagination and repetitive activities, as well as atypical behaviours not specific to autism and other areas of development. Each item on the test is coded by the interviewer based on responses to the questions and via other information sources, such as direct observation of the child. The Autism Diagnostic Observation Schedule (ADOS) is an assessment tool based on observation of social and communicative behaviours in children for whom a diagnosis of autism is considered likely (Lord et al. 1999; Lord et al. 2000). It was originally designed to be used in conjunction with the ADI and is administered by a trained examiner. The assessment lasts approximately thirty to forty-five minutes, during which time the examiner elicits behaviours centred on social interaction, communication and play which are subsequently coded. There are also a large number of screening measures which are used to screen for autism in very young children, as well as older children (Coonrod and Stone 2005). One such measure of relevance to the present study is the Childhood Autism Rating Scale (CARS) (Schopler, Reichler, and Renner 1988) and its revised version, CARS2, which includes an assessment for high functioning autism and Asperger Syndrome (Schopler et al. 2010). The CARS is a behavioural scale with fifteen items which are coded on a four point scale (1 = appropriate behaviour for chronological age and 4 = severely abnormal behaviour for chronological age). Items are coded on the basis of information sources such as clinical observation – either directly or videotaped – and parental report. The diagnostic criteria set out in ICD-10 and DSM-IV reflect the significant progress which has been achieved in the delineation of autism and offer the most recent definition of the syndrome derived from empirical investigation. Similarly, the range and standard of diagnostic and screening tools for autism has increased as knowledge about the disorder has increased. Diagnostic criteria as well as screening and assessment tools will continue to be refined as research uncovers new insights into the current body of knowledge and more is learned about the neurological pathology underlying the behavioural features which form the prevailing basis for identification of the disorder. 4. Conclusion Despite the continuing relevance of both Kanner’s and Asperger’s original observations, the conceptualization of autism has changed significantly since it was first recognized as a disorder. While more is known about the nature of autism, there are no conclusive explanations for many aspects of the

Conclusion

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syndrome. Of direct relevance to the present study are the issues of language impairment and the cognitive deficits associated with autism – in particular, the role of mental representation in cognitive processes. As discussed in this chapter, there is much evidence to support the contention of a cognitive deficit or deficits as a feature of the autistic syndrome. Lexical development is also a cognitive process, and the acquisition of verbs involves domains identified as problematic in autism, such as mental representation and social knowledge. Therefore, how children with autism learn the meanings of verbs, including their function at the level of the sentence, is a question of particular interest in terms of language acquisition as well as broader cognitive development in children with autism.

Chapter 3 Understanding actions, states, and events: Verb learning in children with autism

1. Introduction As I noted in the introduction, the acquisition of verbs, in particular the area of semantic development, is a relatively unexplored aspect of language development in children with autism. Furthermore, there is little consensus in the available literature regarding how knowledge of verb categories in children with autism compares to typical development. Verbs are an interesting category in the context of autism because as well as expressing concepts such as actions, events, or states, verbs also carry information about the number and nature of participants, and the time at which the activity or event took place. Moreover, the acquisition of verb meanings is often dependent on other cognitive skills such as the recognition that human beings have beliefs and desires which motivate their actions. While the semantic development of verbs has featured in studies on language acquisition in typically developing children (Clark 1979; 1981; Gentner 1982; Huttenlocher, Smiley, and Charney 1983), the focus of lexical acquisition research tended to be on object names. However, the question of how children acquire verbs has since become a more central issue (Hirsh-Pasek and Golinkoff 2006; Merriman and Tomasello 1995). One of the major difficulties in studying the semantic development of verbs is that the information encoded is quite complex. In adult language, verbs are used to express actions and events including the relations between agents and objects and non-perceptual features such as causality and intentions of agents. Many researchers have considered verb development in the context of specific stages of linguistic development, or particular semantic domains such as psychological states (Bartsch and Wellman 1995; L. Bloom 1998; Dale and Fenson 1996; Smiley and Huttenlocher 1995). I undertook a survey of these accounts to chart the process of verb acquisition, beginning with earliest words used to denote actions and events, through to the more complex encoding of internal states. This path of verb acquisition in typical development is outlined during the course of this chapter, and I make particular reference to it in the developmental flowchart presented in section 4.2.

Preliminaries

45

2. Preliminaries 2.1. The study The primary aim of the study was to undertake a semantic analysis of verb use in the natural speech of children with autism. On the basis of previous research, verb categories with a closer connection to sensorimotor experience appear to be more straightforward for children with autism to acquire than verb categories whose meanings encode more abstract concepts as well as those more closely intertwined with internal states and social knowledge. Therefore, I hypothesized that the acquisition of verbs would proceed as documented for typically developing children where semantic categories overlap with concepts centred on sensorimotor development, but profile as disjointed for categories whose semantic properties are concerned with social knowledge and awareness of internal states of others. The United States data are annotated transcripts from a longitudinal study on language acquisition in children with autism (Tager-Flusberg et al. 1990) accessed through the CHILDES (Child Language Data Exchange System) database (MacWhinney 2000). The spontaneous interaction of the five children with their mothers was recorded using a video recorder and an audiocassette recorder during bimonthly visits to the children’s homes. The Australian data collection was based on a similar format to the US study. Each visit consisted of the videotaping of the spontaneous conversation and activities of the five children, but the researcher played a more active role in many of the sessions, determined by the preferences of the parents and, sometimes, the children. Visits were conducted over a two to three month period for each child. Across both groups, each recording session was approximately an hour long, with some variation depending on the needs and temperament of the children. Table 3 gives an overview of the children who participated in both studies, including their ages, their IQ and their language abilities. The data was analysed using the CLAN (Computerized Language Analysis) program of the CHILDES Project in order to identify verbs and their conversational contexts. Lexical items found in sentences which came under the following criteria were excluded: self-repetition, imitation (including immediate echolalia and delayed echolalia), routine utterances (for example “go potty”) and incomplete or unintelligible utterances. For a full description of the methodology, see Douglas (2007).

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Understanding actions, states, and events

Table 3. Details of children

US

Aus.

Child

Age

IQ

MLU

Corpus size (words)

Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

3;4 4;7 5;8 6;9 7;7 3;6 4;6 5;6 6;7 7;2

61 94 108 91 75 100 76 75 84 66

1.17 1.73 3.74 3.03 1.46 3.18 4.19 4+ 4+ 4+

10,163 17,217 23,488 19,164 29,630 44,989 38,772 45,300 48,837 36,674

2.2. Semantic categories The semantic categories which provide the framework for this investigation were determined using a number of sources. The primary source was Levin’s (1993) detailed delineation of the verb classes of English categorized by the shared semantic and syntactic properties of individual verbs. Previous studies in child language acquisition were also considered. However, there is often variation in terms of category membership since, as Levin (1993: 17) notes, some meaning components are common to several verb classes. This can result in verbs being considered members of different categories depending on which properties are considered. For example, the verbs come and go may be analysed as verbs of motion or deictic verbs, depending on whether the semantic properties of movement or perspective determine the classification. For the purposes of this study, the classification scheme was influenced by which semantic properties would provide the best opportunity for discussion on concepts which are generally considered difficult for children with autism. A further issue relates to the difficulty in classifying some verbs, which is an inevitable characteristic of any coding scheme. Only a small proportion of verbs proved difficult to assign to the semantic categories. As well as the measures outlined above, for verbs whose status was unclear and category membership was not clarified by context, judgements were made in reference to Levin’s (1993) analysis and verb classification. Table 4 lists the semantic categories analysed with some supporting examples.

Semantic profiles by category

47

Table 4. Semantic categories of verbs Sense types Activity Motion Change of state Stative Deictic Desire Emotion Perception Communication Mental state Causative (periphrastic) Abstract Modal auxiliaries Misuses Other: primary auxiliaries copula

Sample utterances “I played outside”; “no jump off here” “I runned into my room” “don’t break it please”; “I wanna open it?” “I have a circle”; “it can stay up there now” “you give me that one”; “you wanna come here?” “because he wanted to go up and rescue the cat”; “I need the DVD” “I really like girl stuff”; “I think I scareded a ghost” “I can see the red one over there”; “I can hear ambulance coming” “she said goodbye”; “I wanna tell you something “do you know how to shut it?”; “I think it’s on tonight” “can you make this go up”; “don’t let Sally eat it” “I just gotta try and finish this off”; “take a look, mum” “I can have one raisin”; “Eddie might play with them”; “I will leave it on” “I take this one in the camera?”; “if the fire alarm clock sees any fire…” “I don’t want to”; “this is a rainbow”; “she might get dirty”

The categories listed under “other” include syntactic categories which did not form part of the analysis for the present study and motion verbs were included in the category activity. 3. Semantic profiles by category 3.1. Activity In the single word period of language development, typically developing young children recognize similarities in the perceptible aspects of movement and change which are initiated by people and which occur to objects, but with no understanding of intentional actions (Piaget 1954; Smiley and Huttenlocher 1995). It is during the early multiword period

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Understanding actions, states, and events

which usually occurs in the months before a typically developing child’s second birthday that children begin to encode events with a recognition of intention. Huttenlocher, Smiley, and Charney (1983) observed that this did not immediately extend to recognition of the intentions of other people, however, Naigles, Hoff, and Vear (2009) found that the children in their study extended verbs to describe the actions of others as soon as they had acquired them. Typically developing children learn many verbs at this time, including activity verbs which are predominantly used to encode their own actions but are readily extended to describe the actions of others, since activity verbs typically encode observable sensorimotor action (Huttenlocher, Smiley, and Charney 1983; Naigles, Hoff, and Vear 2009; Tomasello 1995). This feature of activity verbs means that they are often observed in the vocabulary of children with autism (Menyuk and Quill 1985). In terms of comprehension, a study by Baron-Cohen, Leslie, and Frith (1986) revealed that children with autism appear to have no difficulty identifying action sequences such as a rock rolling down a hill or a balloon flying towards a tree in a picture-sequencing task. However, studies examining sentence comprehension in children with autism have found that they are more reliant on word order as a comprehension strategy and do not use a semantically based probable-event strategy to discount erroneous encoding of actions such as “the baby carries the girl” or “the box carries the truck” (Paul, Fischer, and Cohen 1988; Tager-Flusberg 1981b). The fact that activity verbs are most frequently used to describe concrete and easily perceived sensorimotor actions means that the lexicons of the children from the present study are likely to contain a high proportion of these verbs. The percentage distribution for each child is represented in Figure 4.2 Not surprisingly, activity verbs account for a large percentage of the lexicons for all children. For Jack and David, over a third of their total verb use occurs as activity verbs and over half of Mark’s utterances containing verbs describe his own actions or the actions of another. Given Stuart’s stage of language development (MLU 1.17), it might be expected that his verb lexicon contain a higher proportion of activity verbs. However, compared to the other children, Stuart’s general verb lexicon is quite small (total token count of 44) which means high token counts from other categories have a greater effect on percentage distributions.

Semantic profiles by category

49

Activity verbs: Percentage distribution 60

54.8

50 38.7

40

34

30 20

26

26.7

30.7 24.2

23.5

22.7

18.2

10 0

% of verb lexicon

Figure 4. Activity verbs: Percentage of total verb use

Table 5 sets out the use of activity verbs for each child, including the number of different verb types used by each child (lexical diversity) and the percentage distribution across the different subjects these verbs were used with. The question mark represents examples where the subject was not overtly coded and was unclear from the context of the utterance. Table 5 reveals that all children use quite a range of activity verbs in the context of their individual verb lexicons. With the exception of Brett, this category contains the highest lexical diversity for each child. Similar to typically developing children, the most frequently used verbs by the children to describe actions are the general purpose verbs do, get and put as well as non-deictic uses of the motion verb go illustrated in the following

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Understanding actions, states, and events

examples: “mummy do it: (M4: 256); “he is getting out” (J2: 927); “put a block in” (S3: 517); and “it’s going backwards” (P2: 1299). Table 5. Lexical diversity and subject use for activity verbs

child Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph US

lexical diversity 6 15 12 27 20 36 40 77 51 48

1 Sg 62.5 54.8 64.9 34.2 37.4 61.3 24.8 41.2 42.7 42.2

Pl 0 0 3.1 9.2 2.2 0.9 13 8.3 11.5 4

Subject use (%) 2 3 Sg Pl Sg 0 0 0 19.4 0 22.6 12.9 0 11.6 15.8 0 23.7 21.9 0 30.8 11.3 0 22.2 30.8 0 29.2 19.5 0 19.3 25.2 0 16.5 28.5 0 19.5

Pl 0 0 3.1 7.9 4.4 1.9 0.9 7.5 1.9 5.1

? 37.5 3.2 4.4 9.2 3.3 2.4 1.3 4.2 2.2 0.7

In terms of subject use, it is unclear whether Stuart extends activity verbs to include utterances with subjects other than the speaker. In the “other” category, the subjects are not overtly coded and the context does not always make it clear who or what was the intended subject. However, the remaining children clearly use activity verbs to encode the intentional actions of others as in the examples “John only played in the sandpit” (Jo3: 83), “then we eat it” (D4: 2508) and “you chucked it away in here” (L1: 633). A noteworthy feature of this category is the number of children who use the verb look to direct attention either to their own actions or something which has engaged their interest. There are clear examples of such uses for Rick, Peter, Liam, Kevin and Joseph, including “oh look at me. I’m dragon barbie” (L3: 743) and “look at behind you, there’s Higgins” (K4: 41). It is not certain in Brett’s case as the context does not make it entirely clear whether he is describing his own actions or calling for his mother’s attention. Nonetheless, the paucity of joint attention behaviour documented for children with autism (Loveland and Landry 1986; Mundy, Sigman, and Kasari 1990) means that the frequency with which at least some children used the verb look to call attention to situations is of interest. In support of previous research, the results from the present study indicate that children

Semantic profiles by category

51

with autism readily use activity verbs to describe a range of actions initiated by themselves as well as others. 3.2. Change of state Change of state verbs are among the earliest verbs acquired in the language of typically developing children, beginning in the early multiword period (Huttenlocher, Smiley, and Charney 1983). According to Tomasello (2003: 214) early change of state verbs acquired include get, find, stop, break, open, and fall-down. Change of state verbs are used initially to describe the child’s own actions upon objects or to produce an end state requested by the child and only later do children begin to describe changes of state initiated by another (Smiley and Huttelocher 1995, but see Naigles, Hoff, and Vear 2009). Young typically developing children also encode simple state changes before more abstract ones (Edwards and Goodwin 1986). For children with autism, there are varying accounts in the literature regarding their competency with change of state verbs. Menyuk and Quill (1985) argued that children with autism have difficulty understanding the meaning of verbs which encode changes of state because of their complexity as compared with simple action verbs. In contrast, Baron-Cohen, Leslie, and Frith (1986) found that children with autism could complete a picture sequencing task detailing changes of state such as a balloon flying into a tree and bursting and a man digging a hole and planting seeds. Moreover, the same children also used change of state verbs in the narrative condition where they were asked to relate the stories of the picture sequences. The early emergence of change of state verbs in typical development suggests that these types of verbs are likely to be well represented in the lexicons of all the children. The percentage distribution for each child is represented in Figure 5. As expected, the data of all children contain examples of change of state verbs. A particularly interesting result is the high percentage of change of state verbs in the lexicon of Rick. These verbs account for almost half of his total verb use and, not surprisingly, change of state verbs are the highest ranking category in his individual profile. Close examination of the data reveals that the overwhelming majority of instances were the verb make which occurred in a single session during which he frequently asked his mother to make things for him as in the example “make a tag please” (R4: 1065).

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Understanding actions, states, and events

Change of state verbs: Percentage distribution 50

44.5

45 40 35 30 25 20 15 10

16.6 9.1

13.9

16.9 13.2

8.8 5.5

8.6

6.9

5 0

% of verb lexicon Figure 5. Change of state verbs: Percentage of total verb use Table 6. Lexical diversity and subject use for change of state verbs

child US

Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

lexical diversity 3 6 18 8 8 18 17 36 20 26

1 Sg 75 9.4 35.1 81.1 17.4 53.4 24.3 45 55.4 44.8

Pl 0 0 0 0 0 1.4 14.8 6.1 4.3 3.5

Subject use (%) 2 3 Sg Pl Sg Pl 25 0 0 0 75.5 0 7.5 0 18.9 0 39.2 4.1 2.7 0 16.2 0 47.8 0 34.8 0 20.5 0 21.9 0 34.8 0 20 0 9.2 0 25.9 13 23.9 0 12 3.3 24.1 0 25.3 2.3

? 0 7.5 2.7 0 0 2.8 6.1 0.8 1.1 0

Semantic profiles by category

53

Table 6 details the use of change of state verbs from the present study, including the lexical diversity within individual lexicons and the percentage distribution across subjects for each child. Table 6 clearly indicates that all children have extended the use of these verbs to subjects other than the speaker. However, for Stuart, the single example with a second person singular subject is a request for his mother to produce an end state to satisfy Stuart’s own goals. That is, he tells his mother to open her hand because she is holding a biscuit he wants. The other children do produce utterances which encode changes of state initiated by someone other than themselves as in the examples “you’re gonna break the castle” (K3: 1134) and “my dad is gonna cut the fence down” (Jo3: 1444). The results do not support the claim that children with autism experience difficulties understanding change of state verbs. With the exception of Stuart, whose language is generally delayed, the children of the present study readily converse about changes of state as reflected in the lexical diversity tally for each child as well as the fact that change of state verbs are among the highest ranking categories within their individual profiles. Furthermore, many of the Australian children demonstrate an ability to engage with more abstract changes of state evident in examples such as “cos they could, might die” (K4: 1218) and “he’s stomping quietly so the barbies don’t wake up” (L3: 707). 3.3. Stative After typically developing children have begun to acquire words for dynamic events encoded by activity and change of state verbs, they begin to learn verbs which denote static states of affairs such as stuck and stay (Bloom, Lightbown, and Hood 1975; Tomasello 1992). Stative verbs first appear in children’s language at approximately two years of age and are initially used to encode the relationship between a person or object and its static location before verbs denoting possession emerge shortly after (Tomasello 2003). I will discuss the development of internal states such as desire and mental state below. While the extent to which children with autism linguistically encode static states of affairs is unknown, comprehension studies have shown that they do not have any difficulty with the concept of locative states. Studies investigating the relationship between language comprehension and sensorimotor skills and the development of social-cognitive skills found that children with autism perform extremely well on object permanence tasks such as looking for a

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Understanding actions, states, and events

hidden object, and physical obstacle tasks where a toy chosen to engage the child’s attention is placed under a transparent box (Carpenter, Pennington, and Rogers 2002; Sigman and Ungerer 1981). The ability of children with autism to complete object permanence tasks suggests that stative verbs encoding locative states, including immediate possession of objects, should be well represented in the data. The percentage distribution for each child is represented in Figure 6. Stative verbs: Percentage distribution 10

9.5

9

9

7.9

8 7

6.3

6

6 5

4

4

2.8

3 1.7

2 1 0

5.8

0

% of verb lexicon Figure 6. Stative verbs: percentage of total verb use

With the exception of Stuart, the data of all children include examples of stative verbs. The absence of stative verbs in Stuart’s lexicon is somewhat surprising since these verbs emerge early in typical development and locative states involve the physical elements of objects or people and place. While the use of stative verbs by Rick and Peter is quite modest, these verbs are well represented in the lexicons of the remaining children. Table

55

Semantic profiles by category

7 sets out the use of stative verbs for each child, including lexical diversity and the percentage distribution across the different subjects encoded in the utterances. Table 7. Lexical diversity and subject use for stative verbs

child US

Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

1

lexical diversity

Sg

Pl

0 2 8 5 6 6 10 11 7 8

0 50 69.8 33.3 50 64 55.3 42.8 39.3 53.4

0 0 3.8 0 0 6 5.3 5.8 5.9 0.8

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 5.7 33.3 10 8 5.3 4.3 22.6 10.8

0 0 0 0 0 0 0 0 0 0

0 0 18.8 22.3 20 22 26.3 39.1 27.4 27.5

0 0 1.9 0 10 0 5.3 7.3 3.6 6.7

? 0 50 0 11.1 10 0 2.6 0.7 1.2 0.8

Table 7 reveals that as well as a low percentage within his overall production of verbs, Rick’s lexical diversity within this category is also small. Both verbs are the verbs of possession, got and have referring to Rick’s immediate possession of an object in the example “have a present” (R2: 345) uttered after receiving a gift and another instance in which the intended subject is unclear. However, while the percentage of stative verbs in Peter’s lexicon was quite small, Table 7 reveals considerable lexical diversity in his production of ten different verbs within this category. Peter and the other children use stative verbs to describe the locative states of objects as in the example “it’s stuck in there” (L1: 586) as well as the physical states of people illustrated in the utterances “you sitting here” (K3: 2228) and “she is wearing a orange shirt” (B4: 1250). More abstract states with the verbs hurt and sleep appear in the data of these children represented in the examples “see this? It hurts” (Jo4: 155) and “cat sleeping” (D4: 1242). Peter and Liam encode more complex states such as repaired objects as in “there, it fixed” (P3: 117) and wearing fine clothes in the example “it’s a dragon dressed up with my `kini” (L3: 750). For all children who produced stative verbs, the majority of instances were used to encode possession, with have and got the most frequently used verbs. With the exception of Rick, the data of all children include uses with subjects other than the speaker. Moreover, Brett and the Australian children also

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Understanding actions, states, and events

encode past and future states of ownership. Thus, excepting Stuart and Rick, the use of stative verbs by the majority of children is quite well developed. 3.4. Deictic Deictic verbs appear in the language of typically developing children at an early age. Studies investigating the language development of young children have found that the verbs come and go as well as more complex deictic verbs such as bring and feed are beginning to emerge in the months after the second birthday (Dale and Fenson 1996; Macrae 1975). However, despite the early uses of deictic verbs, children do not fully master deictic contrasts until as late as nine years of age. In comprehension tasks, typically developing children demonstrate greater competency with the verbs come and bring than go and take (Clark and Garnica 1974). In contrast, a study of children’s spontaneous productions found that go was used with greater frequency than come and errors were very few (Macrae 1975). This apparent disparity is resolved on consideration of the contexts of each study. In spontaneous production, situations requiring strict discrimination of deictic contrasts do not often occur and the apparent ability of children to use these verbs without error is revealed to be false when they are placed in a situation where understanding of person-deixis is crucial to successful completion of the task. In Clark and Garnica’s study, children heard an utterance such as “Can I come into the garden?” spoken by a dog who is located outside a garden with another animal. There is a third animal located inside the garden and the child is asked to identify to whom the dog is speaking. Thus, the child must determine who the addressee is based on the verb contained within the question and the location of the children. For children with autism, the focus of deictic problems has traditionally been on pronoun reversal (Bettelheim 1967; Kanner 1943). However, more recent research has identified a more general problem with deixis, including the use of deictic verbs (Menyuk and Quill 1985). The confusion of deictic terms observed in the language of children with autism is attributed to their problems understanding the shift between speaker and listener perspectives (Tager-Flusberg 1993; 1994) which stems from their difficulties in conceptualising the notion of self and other (Hobson 1993; Lee, Hobson, and Chiat 1994). The well documented difficulties with deixis experienced by children with autism suggest that although instances of deictic verbs are likely to be

Semantic profiles by category

57

present in the data, a high number of erroneous uses may also be present. The percentage distribution for each child is represented in Figure 7. Deictic verbs: Percentage distribution 11.4

12 10 8.4 8

6.7 5.4

6

5.5

4

4 2 0

6.3

6.1

0.8 0

% of verb lexicon Figure 7. Deictic verbs: Percentage of total verb use

Figure 7 reveals that for the majority of children, appropriate uses of deictic verbs are well represented in their verb lexicons. The exceptions are Stuart whose data contain no examples of deictic verbs and Rick whose data contain only a single instance. While the graph indicates that the children demonstrate clear competency with deixis, a number of misuses were also identified. The data of Jack and Joseph included only a small number of misuses in context of their overall use within this category. However, confusion of deictic verbs accounted for a substantial number of the total misuses in the data of Brett and David. I will discuss in detail the nature of these misuses later in the chapter. Table 8 details the use of deictic verbs from the present study, including the lexical diversity within individual lexicons and the percentage distribution across subjects for each child.

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Table 8. Lexical diversity and subject use for deictic verbs

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

lexical diversity 0 1 7 4 6 9 9 13 8 8

1 Sg 0 100 55.6 100 15.4 36.5 10.8 25.5 39.5 43.8

Pl 0 0 0 0 0 1.6 4.1 9.6 9.3 6.2

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 0 0 15.5 0 24.4 4.5 0 0 0 0 30.8 0 30.8 0 11.1 0 44.4 0 27 0 56.8 0 26.2 0.7 29.7 6.9 18.6 0 23.3 9.3 13.7 0 32.5 2.5

? 0 0 0 0 23 6.4 1.3 1.4 0 1.3

Table 8 reveals that for Rick and Jack, deictic verbs are used exclusively with the speaker as subject. The remaining children, in particular Liam, use these verbs with quite a range of subjects, including third person subjects illustrated in the example “he’s going to go to the shops and gonna buy some food” (P4:18). This suggests that these children are able to linguistically encode the perspective of both speaker and addressee, even when they are a third party. The most frequently used verbs were the simple deictic verbs come and go as well as give and take. These verbs were used in a range of contexts and were not restricted to single subject types for each verb. Similar to Macrae’s (1975) study, go appeared with much greater frequency than come, or there was no discernible difference. For those children with a greater lexical diversity, more sophisticated deictic verbs such as steal and pay appear in the data as in the examples “she stole a car” (L3: 870) and “I pay in there” (D2: 1669). This is particularly the case for Liam whose data contained thirteen different deictic verbs including buy, feed and leave. In contrast to previous studies, the data from the present study reveal that some children with autism demonstrate quite advanced development in their use of deictic verbs. 3.5. Desire According to the literature on typical development, verbs of desire emerge in the language of children at around the age of two and are initially used to express only the child’s own desires before expression of the desires of

Semantic profiles by category

59

others emerges some time after the age of three (Huttenlocher, Smiley, and Charney 1983; Bartsch and Wellman 1995). While verbs of desire may be considered members of the category modal (Bybee 1995; Bybee, Perkins, and Pagliuca 1994; Krug 2000), they are addressed as a separate category in the present study, primarily due to their significance in the language of children with autism. There are opposing viewpoints in the literature regarding verbs of desire and children with autism. Some researchers argue that the difficulties these children experience in conceptualising the notion of self and others may inhibit their ability to understand the meaning of internal states such as desire (Menyuk and Quill 1985). However other studies have found that children with autism do talk about their own desires and, although very rarely, the desires of others (Tager-Flusberg 1992;3 Ziatas, Durkin, and Pratt 2003). Consequently, the extent to which children with autism engage with the concept of desire – especially in the context of verb acquisition in general – is an important question. The percentage distribution for each child is represented in Figure 8. Verbs of desire: Percentage distribution 70 61.4 60 50 40 30 20 10

20.2

18.1 9.9 4.8

7.6

6.9

0

% of verb lexicon Figure 8. Verbs of desire: Percentage of total verb use

3.7

2.6

2.3

60

Understanding actions, states, and events

Since verbs of desire are among the early semantic categories to emerge in typical development, it is not surprising that the verb lexicons of all the children in the present study contained instances of these verbs. The most striking result is the percentage of verbs of desire in the lexicon of Stuart – the youngest child from the US data set. While Stuart does produce utterances with both want and need, the verb want accounts for almost two thirds of his spontaneous productions. Examination of the contexts in which this verb occurs revealed that the predominant construction – “want X” – was used for the purpose of having his immediate needs met. For both Rick and Brett, verbs of desire constitute almost twenty percent of their total verb use. In contrast, the use of verbs of desire by Mark and the Australian children is quite modest. Table 9 sets out the use of verbs of desire for each child, including lexical diversity and the percentage distribution across the different subjects encoded in the utterances. Table 9. Lexical diversity and subject use for verbs of desire

child Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph US

lexical diversity 2 2 2 2 1 2 2 4 2 3

1 Sg 100 100 100 100 100 92.8 75.3 73.3 64.3 79.3

Pl 0 0 0 0 0 0 13.9 2.3 3.6 3.4

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2.4 0 2.4 0 1.1 0 9.7 0 3.5 0 18.6 0 21.4 0 10.7 0 13.8 0 0 3.4

? 0 0 0 0 0 2.4 0 2.3 0 0

As Table 9 indicates, all of the children from the US data set use verbs of desire exclusively with the speaker as subject. This suggests that these children do not encode events in terms of intentional actions beyond their own activities. Even children such as Brett and Jack, who produce semantically and syntactically complex utterances with verbs of desire such as “I don’t want to do some work” (B3: 934) and “I need to go to Zayres” (J2: 667), only use verbs of desire with the speaker as subject. David, from the Australian data set, is beginning to extend these verbs to include others as subjects as in the example “need more staples?” (D4: 922) asked of the researcher as she was performing an activity with paperclips, where staples

Semantic profiles by category

61

refer to paperclips. In contrast, the remainder of the Australian children have clearly extended these verbs to express the desires of people other than themselves, illustrated in the following examples: “he wants the boat so I hide it away from him” (L2: 592); “Carol doesn’t want to have a play a game” (K1: 370). While the results support the claim that children with autism may experience difficulties understanding the meaning of verbs of desire, they also indicate quite clearly that this is not the case for all children. 3.6. Emotion The development of emotion verbs in the language of typically developing children is similar to the emergence of verbs of desire discussed above. Children begin to talk about emotions around their second birthday (L. Bloom 1998; Klann-Delius and Kauschke 1996), focussing initially on their own immediate interests before the emotions of others and an understanding of emotions as internal states emerges shortly after. These early verbs are most frequently like and love and negative expressions of emotion in verbs such as hate only begin to appear in the language of some typically developing children at around two and a half years of age (Dale and Fenson 1996). Further development occurs sometime between the ages of four and six when children begin to understand the connection between mental states and emotions (Lagattuta, Wellman, and Flavell 1997). The extent to which children with autism understand and use emotion terms is debated in the literature. Some researchers argue that children with autism are significantly impaired in their ability to understand emotional expressions and the meanings of words relating to emotions (Hobson 1986; Hobson and Lee 1989). In contrast, other studies have found that children with autism do understand simple emotions connected to states of affairs but are impaired in their understanding of emotions connected to thoughts and beliefs (Baron-Cohen 1991; Ozonoff, Pennington, and Rogers 1990; Tager-Flusberg 1992). However, the focus of many of these studies has been on emotion terms across lexical categories and the comprehension of emotions in an experimental setting. Contrary to the early emergence of emotion verbs in typical development, not all of the verb lexicons of the children in the present study contain instances of verbs likely to occur such as like or love. The percentage distribution for each child is represented in Figure 9.

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Understanding actions, states, and events

Emotion verbs: Percentage distribution 12

11.4

10 8 6 4 2 0

0

0

0.4

0.6

1.3 0

1.9 0.1

0.1

% of verb lexicon Figure 9. Verbs of emotion: Percentage of total verb use

With the exception of Stuart, the percentage of verb use in this category is quite small. The data for Rick and Brett from the US group and David from the Australian group do not contain any instances of emotion verbs. In the context of Stuart’s semantic profile, the high percentage of emotion verbs is an unusual result. However, Stuart’s general verb lexicon is quite modest, causing the five instances of the verb like to account for an unusually high number within his overall verb use. Moreover, all instances occurred in a single session and closer examination of the data suggests that the verb was targeted by the mother for this session: her own productions centred quite frequently on this concept in examples such as “you like chips, huh?” (S3: 677) and the majority of Stuart’s utterances were in response to the question “what do you like?” (S3: 739). The fact that it was restricted to a single session and is out of context with Stuart’s profile suggests that the verb has not been generalized to his lexicon. Table 10 details the use of

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Semantic profiles by category

emotion verbs from the present study, including the lexical diversity within individual lexicons and the percentage distribution across subjects for each child. Table 10. Lexical diversity and subject use for emotion verbs

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

lexical diversity 1 0 0 1 1 0 3 6 1 1

1 Sg 100 0 0 100 100 0 33.3 86.6 100 100

Pl 0 0 0 0 0 0 0 0 0 0

Subject use (%) 2 Sg Pl 0 0 0 0 0 0 0 0 0 0 0 0 66.7 0 6.7 0 0 0 0 0

3 Sg 0 0 0 0 0 0 0 6.7 0 0

Pl 0 0 0 0 0 0 0 0 0 0

As indicated in Table 10, the majority of children whose data include verbs of emotion use only a single verb type. In parallel with early verb use in typical development, four out of five of these children have like as the single emotion verb and the lexicons of both Peter and Liam also include the verb like. The exception is Jack whose single use of an emotion verb is hate. The proposal from previous studies that children with autism understand simple emotions is supported by the data. The verb use of the majority of children is exclusively in reference to physical objects as in the example “but I like apples” (Jo4: 502), perceivable attributes such as the utterance “I like pink” (M1: 63), and states of affairs as in “I hate that” (J1: 536) – where “that” refers to the activity of drawing pictures. Only Peter and Liam use emotion verbs with a stronger connection to mental states evident in utterances such as “I think I scareded a ghost” (P4: 1933) and the following exchange between Liam and his mother: (1)

Mother: Child: Researcher: Child:

he did play with your barbies and I'm sorry. I didn't care, I didn't care. oh, that's nice of you. because I can fix it all up. (L4: 890-895)

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Similar to their more advanced use of emotion verbs reflected in their lexicons, the data of Peter and Liam contain the clearest extension of emotion verbs to use with subjects other than the speaker as in the examples “you’ll really like this one” (L1: 511) and Peter’s imaginary conversation: (2) Child: Child: Child:

(child makes the hippopotamus go to the lion and they talk to each other. The hippopotamus is a doctor.) what's the matter? I feel sick, doctor. don't worry, something will make you better. (P4: 1401-1405)

While the data from many of the children is not in conflict with the results of previous studies, Peter and Liam present a different picture. Their use of emotion verbs indicates that while some children with autism may not develop beyond a basic understanding of emotions, there are some children who advance to a recognition of the connection between mental states and emotions. 3.7. Perception Typically developing children’s understanding of perception emerges early. In infancy, pointing gestures begin to appear between the ages of nine and eighteen months and at approximately twenty months, the verb see begins appearing in children’s vocabularies (Bates et al. 1979; Bretherton, McNew, and Beeghly-Smith 1981; Tomasello 1992). By three years of age, children can recognize that other people are able to see and look, and perception verbs are used far more frequently for other people than epistemic verbs (Bloom et al. 1989; Flavell 1977). However, understanding of false perceptions does not begin until children are approximately four years of age (Flavell, Green, and Flavell 1986). For children with autism, development of perception is argued to be concordant with typical development. Studies show that children with autism experience no difficulty with perceptual role taking, but are able to recognize eye gaze as a cue to respond to a question such as “which toy am I looking at?” (BaronCohen 1989; Hobson 1984; Leslie and Frith 1988). Similarly, a study on the verbal expression of perception found that children with autism used

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perception terms as well as children with Down syndrome who were matched on age and productive language (Tager-Flusberg 1992). Figure 10 reveals that not all of the children actually produced utterances containing perception verbs.

Perception verbs: Percentage distribution 3.3

3.5

3

3 2.5 2

1.6

1.6

1.5 0.9

1 0.4

0.5 0

0.7

0

0

0

% of verb lexicon Figure 10. Perception verbs: Percentage of total verb use

While the percentages overall are quite small, Liam and Joseph record the largest number of utterances with verbs of perception. A surprising result is the absence of perception verbs in the data of Stuart, Rick and Mark. On the basis of previous research, it was expected that the data of all children would contain references to perception. Table 11 details the use of perception verbs from the present study, including the lexical diversity

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within individual lexicons and the percentage distribution across subjects and clause types for each child. Table 11. Lexical diversity and subject use for perception verbs

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

lexical diversity 0 0 1 2 0 3 1 5 2 5

1 Sg 0 0 100 50 0 66.7 55.6 46.8 23.5 36.8

Pl 0 0 0 0 0 11.1 33.3 5.1 11.8 7.9

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 0 0 0 0 0 0 0 0 50 0 0 0 0 0 0 0 11.1 0 1.1 0 0 0 24.1 0 20.2 3.8 17.6 0 41.2 5.9 47.4 0 5.3 2.6

? 0 0 0 0 0 11.1 0 0 0 0

For those children whose lexicons include verbs of perception, the verb see was either the only verb (Brett and Peter), or the most frequently used verb. This accords with typical development where the verb see appears early in children’s language. For Brett, perception verbs were used exclusively with the speaker as subject to encode immediate events as in the example “I see the gate” (B1: 749). Similarly, David described immediate events but his verb use included other subjects as well as himself, illustrated in the utterance “…and now we see this one” (D4: 2365). There were only two instances of perception verbs in the data of Jack but, interestingly, they were both used with subjects other than the speaker and included reference to a future event in the example “we’ll see him later” (J1: 383). As indicated in Table 11, the Australian children use perception verbs with a range of subjects: however only the data of David, Liam and Joseph contain references to senses other than sight and hearing as shown in the following examples: “I smell it mummy” (D4: 489) uttered as David smelled the contents of a jar of honey; “I can smell your breath” (L1: 1056) and “feeled like soft” (Jo1: 513). There are no examples of false perception in the data, but Liam and Joseph produce utterances expressing uncertainty: “I think I’m hearing it” (L4: 646) and “I think I saw a snake” (Jo4: 305). In summary, the data indicate that although children with autism may understand perception, their ability to talk about it varies considerably.

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While references to perception were absent in the data of some children, others demonstrated quite advanced understanding of a range of perceptual experiences.

3.8. Communication Communication verbs appear in the language of typically developing children in the months just prior to their second birthday (Dale and Fenson 1996; Tomasello 1995). Early uses are most frequently the verbs tell and say which are used to report the child’s own speech as well as the comments of other people. Utterances also include references to both immediate and past events. Other communication verbs appear in children’s early utterances but are far more rare (Tomasello 1995). Verbs of communication in complex sentences begin to occur in typically developing children’s language at approximately two and a half years of age, and appear to be developmentally prior to complementation with verbs of cognition (Bartsch and Wellman 1995). I will examine in detail the issue of complementation and communication verbs in chapter five. The extent to which children with autism understand communication verbs is unclear. Studies investigating the ability of children with autism to narrate a story from a wordless picture book or a puppet show have yielded mixed results in regard to the children’ use of direct quotations as a storytelling device. Tager-Flusberg (1995) found no significant difference between children with autism and control groups of children with intellectual disabilities and typically developing children on the use of character speech. However, the study by Loveland et al. (1990) revealed differences in the extent to which individuals with autism use verbs of communication to quote the characters from the stories presented. Samples of narratives include one from a sixteen year old male who repeats a character’s words (“I like eggs”) but without defining it as speech (e.g. the fox said “I like eggs”) as well as a narrative from a thirteen year old male which includes numerous references to speech using the verb say (“they say gobble gobble”), despite the narrative, itself, being incoherent (Loveland et al. 1990: 15). As indicated in Figure 11, not all children from the present study produced utterances containing verbs of communication.

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Communication verbs: Percentage distribution 3.3

3.5 3

2.7

2.5

2.1

2

2

1.8

1.9

1.5 1

0.7

0.9

0.5 0

0

0

% verb lexicon Figure 11. Communication verbs: Percentage of total verb use

The overall percentages are quite small and there are no recorded instances of these verbs in the data of either Stuart or Rick. While the fact that communication verbs emerge early in typical development might suggest that all children would be expected to produce them, talk about communication involves linguistic engagement with social interaction – an area in which children with autism are often severely impaired. In the context of their general delay in regard to the acquisition of verbs, the absence of communication verbs in the lexicons of Stuart and Rick is not surprising. Table 12 details the use of communication verbs from the present study.

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Semantic profiles by category Table 12. Lexical diversity and subject use for communication verbs

child Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph US

lexical diversity 0 0 2 2 1 2 5 6 2 5

1 Sg 0 0 55.6 16.7 33.3 75 41.7 61.7 65 43.9

Pl 0 0 0 33.3 0 0 0 6.4 5 0

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 0 0 27.8 0 11.1 5.5 16.7 0 33.3 0 66.7 0 0 0 0 0 25 0 16.6 0 41.7 0 19.1 0 12.8 0 15 0 15 0 17.1 2.4 29.3 7.3

? 0 0 0 0 0 0 0 0 0 0

The verb say was the most common communication verb for those children whose data included examples from this category, followed by talk and tell. As Table 12 indicates, Mark used verbs of communication to speak of his own verbal interactions as well as in imperative constructions as in the example “say goodbye” (M3: 935). In contrast to the other children, the three instances of say in Mark’s data occurred in a single session, suggesting that the verb has not been generalized to his lexicon. The majority of David’s utterances encode the self as subject but his data do include a single reference to his mother talking on the phone in the example “talk a Nana” (D2: 1591). The remaining children produced utterances with quite a range of subjects. Moreover, while Brett and Kevin use communication verbs to talk about immediate events, Jack, Peter, Liam and Joseph report past events, as in the example “the teacher said you have to leave it at school” (Jo3: 166) and “he said bye” (J2: 329) as well as imaginary conversations such as “I will do it said the hippopotamus” (P4: 1311) and “the Kelly said I’m not…I can’t sleep” (L2: 860). In short, the extent to which the children of the present study use communication verbs is quite disparate, ranging from no instances to quite sophisticated examples referring to a variety of communicative acts. 3.9. Mental state The use of mental state verbs in the language of children with autism is an issue which has received much attention in the literature, since mental

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terms are inextricably linked with theory of mind development. In typical development, mental state verbs begin appearing in the language of children just before they turn three years of age (Bartsch and Wellman 1995). These uses are initially routine responses such as “I don’t know” and do not tend to be genuine references to states of knowledge. By the time a typically developing child has reached the age of three, the uses of these verbs have become genuine references to mental states and are beginning to occur with content clauses – an issue I will discuss further in chapter five. In contrast, the development of cognition verbs in the language of children with autism is argued to be quite inhibited (Leslie and Frith 1988; TagerFlusberg and Sullivan 1995). Tager-Flusberg (1992; 1993) asserted that children with autism rarely use language to describe mental states and that the paucity of these terms is directly attributable to the theory of mind deficit of the autistic disorder. However, these studies have targeted cognition terms across lexical categories and the comprehension of mental state terms in an experimental setting. Mental state verbs: Percentage distribution 9

8.4

8 7 6 4.6

5 4 2.9

3 1.7

2 1 0

0

1.2 0.2

1.3

0.4

% of verb lexicon Figure 12. Mental state verbs: Percentage of total verb use

4.6

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Semantic profiles by category

Despite the findings of previous studies that children with autism have difficulty producing and comprehending mental state verbs, the language of a number of the children from the present study includes clear and not infrequent references to mental states. Figure 12 indicates that the US children produce very few mental state verbs. Comparison of the actual utterances reveals that all uses of mental state verbs appear in the routine expression “I don’t know”, suggesting that, for these children, verbs of cognition are not used to refer to psychological states. However, the contrast between the U.S children and the Australian children is quite striking. Table 13 details the use of mental state verbs from the present study. Table 13. Lexical diversity and subject use for mental state verbs

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

lexical diversity 0 1 1 1 1 2 2 7 6 6

1 Sg 0 100 100 100 100 100 100 82.2 81.6 54.7

Pl 0 0 0 0 0 0 0 1.9 0 0

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11.2 0 4.7 0 12.3 0 6.1 0 44.4 0 0.9 0

? 0 0 0 0 0 0 0 0 0 0

While David and Peter only use mental state verbs with the speaker as the subject, their lexicons contain the verb think as well as know and their use of these verbs has progressed beyond formulaic phrases evident in the utterances “I know what go up in this” (D1: 572) and “I think, I think I scareded a ghost” (P4: 1933). Liam, Kevin, and Joseph demonstrate the most advanced use of mental state verbs. Their data contain greater lexical diversity within their individual vocabularies, including verbs such as remember, forget and see as in the example “let me see” (Jo3: 19). They also use mental state verbs with a greater range of subjects and their utterances reveal a stronger sensitivity to psychological states as indicated in examples “um, Oliver…do you know Oliver? (Jo4: 95), “think S winner?”

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(K2:1577) and, in particular the following exchange between Liam and his mother: (3)

Mother: Child: Mother: Child: Mother: Child: Mother: Child:

cos the stickers go in the book. I know one that I can do. well, no, you have to follow the instructions in the book. it is ‘tructions, mum. you get stickers and you put them on matching things. yes, I know that mum. think. I’m not thinking, mum, I know it. (L3: 113-121)

Clearly, the data indicate that at least for some children with autism, the use of verbs of cognition develops beyond formulaic utterances to enable expression of their own mental states and acknowledgement of other people’s. 3.10. Causative Typically developing children begin to recognize movement of objects caused by another person from approximately two years of age (Smiley and Huttenlocher 1995). Prior to this understanding of the notion of causality, young children do not differentiate between simple movement of objects and object movement as initiated by another person (Golinkoff et al. 1984). The linguistic expression of causality begins around the age of two or two and a half. This is evident both in typically developing children’s erroneous uses of noncausative verbs as causative, as in the example “jump me down” (Clark 2003), as well as the appearance of periphrastic causative verbs, which is the focus of this section. Children with autism do not appear to have difficulty with the notion of causality. Previous research has indicated that these children do develop knowledge of causality in accordance with typical development (Baron-Cohen, Leslie, and Frith 1986; Sigman and Ungerer 1981). Moreover, their ability to describe causal relations between a person and an object as well as between objects appears to be equally well developed. Baron-Cohen Leslie, and Frith. (1986) found that children with autism performed well on a causal picture sequencing task in both the object to object condition as well as the person to object condition and they

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73

were able to appropriately describe the events represented by the pictures in the narrative condition. However, the absence of studies examining the use of periphrastic causatives in the language of children means it is not certain whether or not these verbs should be expected to appear in the data of the present study. Figure 13 indicates that only some of the children produced utterances with periphrastic causative verbs. Causative verbs: Percentage distribution 3 2.4

2.5 2 1.5

1.1 0.9

1

0.5

0.5 0

0.3 0

0

0

0

0

% of verb lexicon Figure 13. Causative verbs: Percentage of total verb use

Stuart, Rick, Brett and Mark from the US data set and David from the Australian data set did not produce any examples of causative verbs. Given that previous research suggests children with autism do not experience difficulty with the notion of causality, the absence of periphrastic causative verbs might be considered a surprising result. However, the syntactic complexity of utterances containing the verb make and the semantic complexity of the verb let may be reasons why the data of only some children in the present study included utterances with causative verbs.

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While the percentages, overall, are very small, Peter has a higher percentage of periphrastic causatives in his verb lexicon than the other children. The majority of these verbs are the verb make, encoding direct causation. Table 14 sets out the use of causative verbs for each child, including lexical diversity and the percentage distribution across the different subjects encoded in the utterances. Table 14. Lexical diversity and subject use for causative verbs

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

lexical diversity 0 0 0 1 0 0 2 2 1 2

1 Sg 0 0 0 0 0 0 3 19.2 33.3 0

Pl 0 0 0 0 0 0 3 0 0 0

Subject use (%) 2 Sg Pl 0 0 0 0 0 0 100 0 0 0 0 0 60.6 0 57.7 0 33.3 0 50 0

3 Sg 0 0 0 0 0 0 33.4 23.1 33.3 50

Pl 0 0 0 0 0 0 0 0 0 0

Jack, Kevin and Joseph each produced a small number of utterances with causative verbs, including uses with someone other than the speaker as the subject illustrated in the following examples: “let me help her” (J2: 944) uttered as Jack was attempting to help his mother repair a broken toy Snoopy; “you will make it break” (K3: 1248); and, “it makes you don’t get wet” (Jo2: 926) in answer to the question “what does an umbrella do?”. Peter and Liam produced quite a large number of constructions with causative verbs and, as indicated in Table 14, over half of these included second person singular subjects as in the examples “can you make this go up” (P1: 1388) and “now you’ll let me have this bit, mum?” (L2: 1184). Interestingly, both Jack and Liam use the causative verb let either exclusively, in the case of Jack, or with a much higher frequency than make. This result is noteworthy as let is a verb which encodes permissive causation and, hence, the speaker is arguably more attuned to the internal state of the addressee in imperative constructions, or the subject of the verb (Shibatani and Pardeshi 2002). The results suggest that while children with autism may understand physical causality, only some children can encode

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this linguistically in the use of periphrastic causatives. Moreover, the elements of perspective-taking and internal states included in the meaning of the permissive causative, let, may mean that it is a more difficult concept to acquire for these children. 3.11. Abstract In this section I examine the use of abstract verbs which do not fall into any of the internal state categories addressed above, as well as abstract extensions of verbs denoting actions or events. Early research on typically developing children’s comprehension of metaphorical language suggested that the developmental process is slow and only begins after the acquisition of literal language (Inhelder and Piaget 1958). However, investigations of children’s spontaneous language reveal that young children’s utterances are full of figurative extensions of nouns (Bowerman 1982; Winner 1978) and more recent studies have found that understanding of simple metaphors, such as “the radio growled” (Pearson 1990: 202), emerges between the ages of three and four (Epstein and Gamlin 1994; Özçaliskan 2005; Pearson 1990). In terms of production of verbs in typical development, figurative language appears early in children’s speech. Conventional extensions of activity verbs such as turn in the context “turn on the light/television” etc. and inherently abstract verbs such as share are evident in typically developing children’s language in the months after their second birthday (Dale and Fenson 1996; Tomasello 1992) and the acquisition of these semantically complex verbs occurs as a gradual process (Gentner 1978). In the context of autism, it is argued that verbs with a greater degree of abstractness and particularly metaphoric extensions of verbs to create multiple meanings are problematic for children with autism to acquire (Menyuk and Quill 1985). However, in a study which examined the ability of children with autism to comprehend concrete and abstract nouns, Eskes, Bryson, and McCormick (1990) concluded that abstract words were as meaningful to the children with autism as to the typically developing controls. Similarly, Kanner (1946) argued that metaphorical expressions used by children with autism are extensions based on concrete personal experiences (e.g. a child calling himself Blum when he was accused of not telling the truth, the origin of the expression being a company slogan “Blum tells the truth” which the child saw in the newspaper). Happé (1993) investigated the effect of theory of mind abilities on the comprehension of similes and metaphors in children and adults with autism. She found that

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the children with autism who had passed at least a first-order theory of mind task (attribution of false beliefs about a state of affairs) were much better able to correctly choose the missing element from sentences such as “The dancer was so graceful. She really was …a swan” (Happé 1993: 118119). Thus, it is not clear whether or not abstract verbs are likely to appear in the data of the present study. Figure 14 indicates that the majority of children produced utterances with abstract verbs. Abstract verbs: Percentage distribution 6 4.8

5

5

4.8

4 3

2.8

2.6 2.2

2.2

2 1.2 1 0

0

0

% of verb lexicon Figure 14. Abstract verbs: Percentage of total verb use

The data of neither Stuart nor Rick included any examples of abstract verbs and Mark’s verb lexicon contained only a very small number of instances. However, Figure 14 reveals that Liam, Kevin and Joseph use many more abstract verbs by comparison. Table 15 details the use of abstract verbs

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from the present study, including the lexical diversity within individual lexicons and the percentage distribution across subjects for each child. Table 15. Lexical diversity and subject use for abstract verbs

child Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph US

lexical diversity 0 0 8 3 2 6 11 29 21 17

1 Sg 0 0 44 40 0 50 13.2 31.3 52.6 23.4

Pl 0 0 0 0 0 0 13.2 6.1 3.4 0

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 0 0 8 0 44 0 0 0 60 0 0 0 50 0 0 0 41.7 0 18.4 0 52.6 2.6 7.8 0 40.9 8.7 23.7 0 16.9 1.7 10.9 0 51.6 14.1

? 0 0 4 0 50 8.3 0 5.2 1.7 0

Table 15 reveals that, with the exception of Mark, all children whose data contain instances of abstract verbs clearly include uses with subjects other than the speaker. The most frequently used abstract verbs across children are figurative uses of the light verbs such as “I go sleep” (D: 1749) and “take pictures on mommy’s camera please” (B2: 878) which is a common feature of these verbs (Newman and Rice 2004). For Jack and Mark, use of abstract verbs is restricted to conventional extensions illustrated in the examples “time to tell time” (J4: 821) and “turn lamp [on]” (M4: 1036). In contrast, the data of Brett and the Australian children include inherently abstract verbs as well as metaphorical extensions as indicated in the following examples: “I want to earn the farm” (B1: 1030); “I share [with] Melanie” (D: 1749); and “mean that I have to fix it, ah, this” (P1: 966). The more advanced development of abstract verbs for Liam, Kevin and Joseph is reflected in their greater lexical diversity within this category. Moreover, the data of these children contains verbs in which the abstractness consists of references to social relations, as in the utterances “I hope the fish will protect them [baby fish]” (L1: 868), “no, you’re cheating” (K3: 1287) and “the teacher said you’re not allowed to” (Jo3: 105). In summary, the data suggest that while some children with autism are restricted in their acquisition of abstract verbs, other children engage with quite complicated concepts in their use of these verbs.

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3.12. Modal auxiliaries In this section I examine the acquisition of modal auxiliary verbs in the language of children with autism, but I do not include the use of the primary auxiliaries be, have, and do and copular verbs. While the manner in which individuals with autism encode temporal and aspectual meanings is of interest (Bartolucci and Albers 1974; Roberts, Rice, and Tager-Flusberg 2004; Perkins et al. 2006), this issue was not a focus of the present study. However, that modal auxiliaries encode information regarding social knowledge and inferences makes them particularly relevant in the context of a semantic profile for the acquisition of verbs in children with autism. In terms of delineation of categories, the distinction which is often drawn in the literature is between root and epistemic meanings. Epistemic meanings encode judgements about the truth of a proposition. However, dividing root meanings further into the categories of deontic (obligation and permission) and dynamic (physical necessity and possibility) allows for the examination of modal use encoding social information, namely deontic, in the language of children with autism (Palmer 1979; Perkins 1983). The first examples of modals in the language of typically developing children occur at approximately two years of age. Early uses consist of the negative forms of can and, less often, will, namely can’t and won’t (L. Bloom 1970; Leopold 1949). Shortly after these initial appearances, the modals can and will begin to be used productively in a range of syntactic environments (Perkins 1983; Stephany 1986). Despite the frequency with which young children use the modals can and will, they are restricted to ability, permission and intention of primarily the speaker as well as the addressee, but not third persons (Fletcher 1979; Wells 1979). Quasi-modal expressions such as have got to and be going to appear early along with the primary modals can and will (Stephany 1986; Wells 1979). Deontic uses of the other primary modals must and may along with the secondary modals would, could, should, and ought to typically appear by the age of three (Wells 1985). While there are limited instances of the epistemic modals may and might in the language of typically developing children prior to the age of four (Wells 1985), it is only after four that the acquisition of epistemic modality begins (Stephany 1986; 1993), and although uses of both primary and secondary modals are generally evident in children’s language by the age of five, mastery of the modal system in English continues to develop into the later childhood years (Perkins 1983). There are only a small number of studies which have investigated the use of modal auxiliaries in the language of individuals with autism. Nuyts

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and De Roeck (1997) examined the use of epistemic modality by four speakers of Dutch who were high-functioning individuals with autism. They found that three of the four children showed normal use of the epistemic forms under investigation and only the youngest child at nineteen years of age displayed difficulties. In contrast, Tager-Flusberg (1997), examining data from the same transcripts utilized for the present study, found that young children with autism predominantly used modals to express future tense and requests for permission, with very little epistemic use. However, there were not many instances of epistemic modals in the language of the control group of children with Down syndrome which means it is difficult to conclude whether the absence of these modals is due to problems in attributing mental states or simply an effect of language delay. Moreover, requests for permission warrant closer investigation as they may indicate some awareness of individual minds. Table 16 sets out the use of modals by the children from the present study. Table 16. Lexical diversity and semantic functions for auxiliary modals child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

lexical diversity 0 0 4 4 1 4 5 11 7 6

Dynamic 0 0 40.7 90 100 69.2 51.9 54.8 64.7 45.8

Modalities (%) Deontic 0 0 58.3 20 0 30.8 48.1 15.2 30.7 52.7

Epistemic 0 0 1 0 0 0 0 30 4.6 1.5

As Table 16 reveals, there were no auxiliary modals in the data of either Stuart or Rick from the US children. For those children whose data contain modals, the majority of instances fall into the category of dynamic modals, with the exception of Joseph whose deontic uses were marginally higher. Similar to typically developing children, dynamic uses consisted mostly of the primary modals can (expressing ability) and will (encoding future tense and intention) as well as the quasi-modal be going to (future tense). Deontic modals were substantially represented by can and the quasi-modal have (got) to. Only Liam, Kevin and Joseph from the Australian data set used secondary modals and the most frequently used of these was dynamic could.

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Table 16 also indicates that Liam is clearly the most advanced of all the children, both in terms of his lexical diversity as well as his use of epistemic modals. His data contains five different secondary modals and while there are no instances of the epistemic primary modals may and must, there are many epistemic uses of might as in the example “it might have happened to Dennis’s” (L1: 165) uttered upon finding that his homework sheet was damaged by the printer and speculating that the same thing could have happened to his classmate’s sheet. With the exception of his idiosyncratic use of the quasi-modal used to which will be addressed in the following section, Liam demonstrates quite a sophisticated understanding of the use of modals which is nicely illustrated in the inclusion of the quasimodal to mark future tense within a proposition embedded in a past tense matrix verb: “I thought you [were] gonna bring a barbie” (L4: 592). It is noteworthy that the data of Brett and Jack include deontic uses since, as discussed above, their use of mental state verbs consists entirely of the formulaic expression “I don’t know” and deontic modals express obligation and permission. In particular, Brett’s data contain many requests for permission. It is possible that can is used in these instances as a politeness convention as demonstrated in the following exchange: (4) Child: Child: Mother: Child: Mother:

(child walks over to where mother is cooking) I want a cookie. mommy. what? can I have a cookie? no. (B2: 314-319)

However, the following example suggests that Brett may have some understanding of asking permission: (5)

Child: Mother: Child: Mother: Child: Helen:

can I play outside? ask helen. ellen. helen. helen, can I play outside? why don't you play with this? (B4: 1489-1494)

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The single epistemic use for Brett is contained within the phrase “that knife can cut you badly” (B2: 321) uttered as he watched his mother cutting vegetables. According to Perkins (1983: 35) such uses of can include an epistemic sense. However, the status of this phrase is ambiguous as, despite Brett’s appropriate use, it is very likely that he has heard the same or similar uttered by his mother, and his use is simply a formulaic repetition. The data from the present study indicate that the process of acquisition for modal auxiliaries accords with typical development in the order in which the different types of modality emerge and the particular modals which appear early in children’s language. However, in contrast to previous research, the data also suggest that it is possible for children with autism to develop an understanding of mental states and express this through their use of epistemic modals. 3.13. Misuses The nature of misuses, or non-adult uses, in the language of children with autism provides further information regarding the nature of the semantic development in the acquisition of verbs. That is, as well as examination of verb use within the semantic categories as presented in the previous sections of this chapter, investigation of the types of misuses which appear in the data addresses further the question of whether there is evidence of atypical development. In the context of overall verb use, the percentages of verbs classed as non-adult were very low. There were no examples identified in the data of Stuart and Rick and rate of misuses was below two per cent for the remaining children. This does not offer support for the claim that semantic development, at least within the lexical class of verbs, proceeds in a manner not concordant with typical development. The majority of misuses in the data fall into the category of general semantic misuses, or, uses that deviate from adult usage. For Brett, a small number of misuses relate to the effect of water on fire (“it burns the building” B4: 1289) and the attribution of emotions to inanimate objects outside the context of pretend play (“it’ll [the building] cry” B4: 1311) for which there does not seem to be any plausible explanation. Interestingly, these errors occur when Brett is describing events depicted on picture cards which he has clearly been learning to describe. A small number of semantic overextensions appear in the data: the overextension of the verb paint where Mark answers “painting” (M3: 561) when questioned about a picture card in which a man is icing a cake; Joseph’s comment “he’s punching his

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leg onto a bad guy” (Jo1: 1615); and Joseph’s overextension of the causative element in the verb give in the sentence “I gave my whole body under the water” (Jo2:1618). David and Peter produce a number of semantically implausible constructions such as “buy money” (D4: 136) and “make this out the way” (P1: 1468). Peter’s data also includes the utterance “my throat is melting” (P1: 1273) which does not accord with adult usage but is creative, nonetheless. Semantic errors involving incorrect choices of words but from the same or similar semantic domain occur in examples such as “you hear me speeding” (L4: 2006) for skidding and “I’ll count: a, b, c…” (K2: 834-835). Both Kevin and Joseph extend verbs requiring animate subjects to use with inanimate participants as in the utterances “when I throw that dice it makes six” (K3: 376-378) and “when the alarm sees any smoke…” (Jo1: 153). Joseph’s statement “the cold let me had all sores” (Jo4: 104) is an inappropriate use of the periphrastic causative let. Interestingly, this is an error observed in the language of typically developing children (Bowerman 1993). As difficulty with deixis is an issue well discussed in the literature on autism (Hobson 1993; Lord and Paul 1997), I address errors indicating problems in this area separately from the general semantic misuses. Jack produces a small number of errors such as the utterance “I’m gonna take my seatbelt on” (J2: 357), where the context makes clear he was referring to the act of putting on a seatbelt. However, his use of deictic verbs (as presented in section 3.4) indicates that he does not have problems with deixis in general. A substantial proportion of the misuses in the data of Brett and David involve deixis, resulting in examples such as “can I give the big yellow one to me” (B3: 26), where Brett is asking if he can have the yellow play dough, and “I take glasses” (D1: 1332) uttered as David was giving his mother her glasses. However, the total number of misuses for each child accounted for just over one per cent of their general verb use and, as shown above, their correct uses of deictic verbs clearly outnumber the errors. The final type of misuse in the data can be broadly termed syntactic misuses. Brett, Peter, Liam and Kevin all produce misuses of the primary auxiliary be as in the examples “they’re be sitting behind the fence…” (B4: 1280) and “I was having this game” (K4: 1412). Both Liam and Kevin occasionally nominalize verbs, making them complements of the copula verb get illustrated in the utterances “…and I don’t get a cry” (L3: 634-635) and “I just got hammer my thumb” (K3: 1870). A single misuse of a modal auxiliary appears in Joseph’s data (“if you do I’ll disappear and then you can’t even find me” (Y4: 727)) and almost one third of Liam’s total

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misuses occur with the quasi-modal used to: these misuses indicate that used to functions as a past tense marker without the habitual element, leading to the production of sentences such as “she used to die” (L1: 757) in reference to the passing of his grandmother. Perkins et al. (2006) found similar problems with tense and aspect in the language use of adults with autism. In summary, the majority of the semantic misuses identified in the data are attributable to the phenomenon of overextension which is a widely discussed feature of the lexical development of typically developing children (e.g. Rescorla 1980; Clark 1993). Similarly, misuses within semantic fields are suggestive of semantic organization comparable to typical development. 3.14. Lexical innovations When typically developing children become aware of covert semantic categories within the verb lexicon, reorganizational processes occur, resulting in overextensions. A well-documented example of this phenomenon is the innovations which occur when children develop an understanding that English verbs often express a cause and effect relation (Bowerman 1982; Clark 2003). That is, children may use verbs correctly and then overextend the causative element to noncausative verbs. The data of Kevin from the present study contained two such innovations in which transitive verbs are derived from intransitive verbs: “daddy just jumped me off” (K3: 990) and “I collapsed it” (K: 471), where “it” refers to a tower made of building blocks. A similar process results in lexical innovations in which children coin new verbs from nouns (Clark 1982). Peter and Liam each produced a single example of such verbs. The lexical innovation for Liam occurred in the question “how you make her ballet?” (L4: 826) and Peter’s innovation appears in the following exchange: (6) Researcher: Child: Researcher: Child:

(researcher and child are playing with farm animals) let’s put them back in their field no, don’t field yet no? he’s gonna chasing the cows (P1: 634-637)

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Bowerman (1974) argues that the appearance of lexically creative causative verbs is developmentally linked with the appearance of periphrastic causative verbs in the language of typically developing children. It is interesting to note, then, that periphrastic causatives feature most strongly in the semantic profile of Peter, with Liam ranked second highest. Lexical innovation is by no means unprecedented in children with autism as neologisms or odd phrases are occasionally observed in their language (Kanner 1943; Volden and Lord 1991). However, the types of innovations discussed above display a sensitivity to quite subtle semantic patterns which results in a kind of lexical creativity not predicted by previous accounts of the language use of children with autism (Menyuk 1978; Paul 1987; Rutter 1970). 4. Overview In the remainder of this chapter I summarize the verb use of children across the semantic categories under investigation and attempt to draw out some interesting patterns of results which emerged from the data. I present a combined profile of the semantic development of verbs in the first section, and the pattern of results is examined in the context of previous accounts in the literature of the abilities of children with autism. I propose a developmental path of acquisition for verbs in the language of children with autism drawn from the combined profiles, and I compare this with verb acquisition in typical development. I also address the issues raised by the order in which the children are placed in terms of the developmental stages they have reached. Finally, I consider possible explanations for the pattern of results regarding lexical diversity within the lexical class of verbs. 4.1. Semantic profile of verb use On the basis of previous research addressing the semantic development of children with autism, it would be expected that those categories which encode concrete and easily perceived sensorimotor actions or events such as activity and change of state will be well represented in the data of all children. Similarly, the less semantically complex internal states of perception and desire should also be included. In contrast, verbs of emotion, categories incorporating social awareness such as deixis and communication and verbs requiring an understanding of cognitive

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processes are not likely to be well represented in the data. The individual profiles of all ten children are summarized in the following table. The ordering of semantic categories approximates the order of emergence in typically developing children’s acquisition of verbs, and the figures are percentages of total verb use for each child.

Change of State

Stative

Deictic

Desire

Perception

Communication

Abstract

Emotion

Mental State

Causative

US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

Activity

Child

Table 17. Semantic profile of verb use

18.2 26 26.7 34 54.8 38.7 24.2 23.5 30.7 22.7

9.1 44.5 8.8 16.6 13.9 13.2 16.9 5.5 8.6 6.9

0 1.7 6.3 4 6 9 2.8 5.8 7.9 9.5

0 0.8 5.4 6.7 8.4 11.4 5.5 6.1 4 6.3

61.4 20.2 18.1 9.9 4.8 7.6 6.9 3.7 2.6 2.3

0 0 0.4 0.9 0 1.6 0.7 3.3 1.6 3

0 0 2.1 2.7 1.8 0.7 0.9 2 1.9 3.3

0 0 2.6 2.2 1.2 2.2 2.8 4.8 5 4.8

11.4 0 0 0.4 0.6 0 1.3 1.9 0.1 0.1

0 1.7 0.2 0.4 1.2 1.3 2.9 4.6 4.6 8.4

0 0 0 0.9 0 0 2.4 1.1 0.3 0.5

This pattern of results is not related to age or IQ as might be expected. Liam and Peter demonstrate the most even rate of development in their usage of verbs for these categories, and yet Liam is fifth youngest and Peter is third youngest of the ten children. In terms of IQ, Liam has the third lowest IQ at 75 and Peter has the fourth lowest at 76. The oldest child is Mark at 7 years and 7 months of age and Table 17 indicates his use of these verbs is quite low compared to the other children. Similarly, Brett has the highest IQ at 108 but uses far fewer verbs from these semantic categories. I will further explore this pattern of results in the following sections. 4.2. The developmental path of verb acquisition Early research into the semantic development of children with autism concluded that for those children who acquire productive language, the process is atypical and deviates from the documented path of acquisition in

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typical development (Goldfarb 1961; Hermelin and O’Connor 1967; Menyuk and Quill 1985). However, more recent investigations have found that general lexical growth and conceptual development in children with autism proceeds in accordance with typical development (Lord and Paul 1997; Tager-Flusberg 1985a, b; Tager-Flusberg 1986). Despite clear indication of delayed acquisition, there was no evidence in the present study which would suggest that the semantic development of verbs in children with autism progresses in a manner not congruent with typical development. The individual results regarding verb acquisition are represented collectively in a developmental flowchart. The boxes on the left represent the various stages of development evident in the data, including semantic categories of verbs as they appear as well as the range of subjects each verb category is used with. These stages follow the path documented for typically developing children as presented in this chapter. That is, in the earliest stage, activity, change of state and stative verbs are used with only the speaker as subject, followed by the next stage in which a large number of verb types are acquired. These are: verbs of desire, deixis, communication; formulaic uses of mental state verbs; and, perception, abstract and emotion verbs. The extension of verbs to uses with subjects other than the speaker begins for all categories except desire and emotion while mental state verbs are restricted to the formulaic expression “I don’t know”. In the third stage, the semantic categories of mental state and causative begin to emerge used predominantly with the speaker as subject. Finally, the most advanced stage emerges with a full complement of semantic categories in which verbs are used with multiple subjects. The location of the children is an approximate indication of their level of semantic development, based on the data presented in section 3. There are a number of possible anomalies in the data which may cast doubt on the claim that children with autism acquire verbs in the same order as typically developing children. The first issue is that despite what his location on the developmental flowchart implies, there are no examples of perception verbs in Mark’s data. However, examination of the data reveals that Mark readily comprehends perception verbs (e.g. correctly responding to his mother’s request “tell me what you see on the cards”) and he does use the verb look – the active counterpart of the perception verb see. The second issue is the placement of David from the Australian data set. His location on the developmental flowchart suggests that his data contain emotion verbs, whereas it was shown above that it does not. However,

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David does use emotion terms from other word classes as illustrated in the following exchange: (7) Mother: Child:

(mother pretends to eat child again and child is laughing) what? it's funny. (D1: 909-911)

Categories: activity, change of state and stative Subjects: speaker only Stuart (US): 3;4 IQ 61 Categories: desire, deixis, communication, mental state (formulaic), perception, abstract, emotion. Subjects: speaker only for desire, emotion and mental state (formulaic)

Rick (US): 4;7 IQ 94

Mark (US): 7;7 IQ 75 Brett (US): 5;8 IQ 108 David (Aus.): 3;6 IQ 100

Categories: causative, mental state Subjects: speaker only for mental state and emotion.

Jack (US): 6;9 IQ 91 Peter (Aus.): 4;6 IQ 76 Kevin (Aus.): 6;7 IQ 84

Categories: no new

Joseph (Aus.): 7;2 IQ 66

Subjects: multiple subjects for all

Liam (Aus.): 5;6 IQ 75

Figure 15. Developmental flowchart of verb acquisition in children with autism

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While there does not appear to be evidence of atypical development, the order of the children in terms of the stage of development reached is an interesting feature of the data. That is, the ranking of each child is not consistent with either their age or IQ. As indicated in Figure 15, Mark from the US data, despite being the oldest child, is less advanced than David – the youngest child from the Australian data set. Similarly, Brett from the US data set who has the highest Performance IQ demonstrates less advanced semantic development than many of the other children. It appears that language development (as measured by MLU) is a better indicator of the stage of verb acquisition reached by each child. That is, those children with an MLU of less than two are between stages one and two in terms of their semantic development, those with an MLU between three and four are around stages two and three and those with an MLU above four are the furthest advanced. However, the data are by no means a neat fit and MLU does not provide a satisfactory explanation as to why some children display more advanced semantic development than others irrespective of their age and their IQ. Moreover, studies in typical development have found that a child’s MLU is considerably influenced by his or her expressive vocabulary skills (Dethorne 2002; Dethorne, Johnson, and Loeb 2005; Miller 1991). Dethorne, Johnson, and Loeb argue that, as such, MLU is better viewed as a global measure of expressive language ability than as a measure of grammatical development as originally proposed (Brown 1973). Thus, for the present study, MLU does not offer an independent measure which can account for the advanced semantic development of some of the children. I will address the issue of which factors might affect the rate of semantic development in verb acquisition in chapter six, where I will suggest social cognitive skills play a significant role. 4.3. Lexical diversity Estimates of lexical diversity are the most frequently employed measures to assess the vocabulary ability of children as recorded in spontaneous speech. The intent is to measure the variety of words used by a child in a spontaneous language sample. There are a number of different ways in which lexical diversity is measured but the two measures most frequently employed are a basic count of the number of different words (NDW) from a sample standardized by time or number of utterances (Miller 1991) or a type-token ratio (TTR) generated by dividing the NDW by the total number of words (TNW) from the sample to yield a ratio as a measure of lexical

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diversity (Fairbanks 1944; Richards 1987). A small number of studies have used this measure as an assessment of the general vocabulary ability of children with autism. Tager-Flusberg et al. (1990) analysed the number of different word roots from a 100-utterance sample as an incremental measure of lexical diversity over a two year period.5 In a study examining pragmatic and vocabulary development in children with autism, Rollins (1999) used the number of different words produced in a 20-minute sample as a measure of general vocabulary development. While there do not appear to be studies specifically examining the verb diversity in the language of children with autism, investigations into verb use in children with SLI frequently use verb diversity, either as verb type token ratio (vTTR) (Watkins, Rice, and Moltz 1993) or number of different verbs (NDV) as a measure (Conti-Ramsden and Jones 1997). Verb diversity 200 180 160 140 120 100 80 60 40 20 0

NDV Figure 16. Verb diversity by number of different verbs

The verb diversity of each child from the present study is illustrated in Figure 16. The measure used was a basic count of the number of different verbs (NDV) produced in the four session sample. Type/token ratio was not used as a measure due to the large variation between the children in terms

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of expressive language ability and the resulting small token counts of some children. To reduce the possibility of a potential confound with MLU, the grammatical categories of copular and auxiliary (including the quasimodals) were not included in the calculation of NDW. However, it must be noted that verb diversity as measured by the number of different words cannot offer a controlled measure of verb diversity as the “chattiness” factor is not constrained in a sample only marginally matched on session lengths. Even as a rough indicator of verb diversity, the data suggest that an increase in the number of different verbs is not related to chronological age or Performance IQ. Only Stuart as the youngest child with the lowest IQ fits this profile. However, the verb diversity of the remaining children is not predicted by either age or IQ. Liam has one of the lowest IQs and is middle-ranked in terms of age, but has the largest vocabulary of verbs. Similar to the profile of semantic development discussed above, it appears that MLU is better indicator of verb diversity, even with the exclusion of grammatical categories: children with an MLU of less than two have the lowest number of different verbs; those children with an MLU between three and four show a greater range; and, children with an MLU of four or above have the highest number of different words. However, the data are not well distributed within these sub-groups if the number of different verbs (NDV) is considered in the context of the total number of verbs (TNV) as shown in Table 18. Table 18. Verb diversity US

Aus.

Child Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

NDV 13 27 59 56 46 84 102 196 121 129

TNV 44 113 605 177 157 480 916 1512 728 871

Within the group of children with an MLU between one and two (Stuart, Rick and Mark), Mark’s NDV is almost double that of Rick, despite Mark’s MLU of 1.46 being lower than Rick’s at 1.73 and both children having a

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comparatively similar TNV. Similarly, in the MLU above four group, Peter has a lower NDV, despite having a larger total number of verbs than Kevin and Joseph. The association between NDV and MLU becomes even less clear in the group of children with an MLU between three and four. Although Brett has a higher MLU than David (3.74 v. 3.18), David has a larger NDV from a smaller TNV. An interesting case is Jack from the US data whose MLU is 3.03. His language shows a surprising amount of variation in his verb use considering his TNV is considerably lower than both Brett’s and David’s. In summary, the measures of chronological age, Performance IQ and MLU do not provide an adequate explanation of the rate of development for each child in the acquisition of verbs either in terms of the stages of semantic development as discussed above or in verb diversity as presented here. I will address this issue further in the general discussion. 5. Conclusion The key results of the present investigation into the semantic development of verbs in the language of children with autism can be summarized as follows. I hypothesized that the acquisition of verbs would proceed as documented for typically developing children where semantic categories overlap with concepts centred on sensorimotor development, but profile as disjointed for categories whose semantic properties are concerned with social knowledge and awareness of the internal states of others. In support of researchers who argued that conceptual development in children with autism is unimpaired, analysis of verb use revealed that verb acquisition proceeds in the same manner as typical development in terms of the order of emergence of category types. In particular, there was little evidence to support a theory of uneven development. As expected, categories involving sensorimotor perception and simple internal states were strongly represented in the data. However, contrary to expectation, categories requiring greater abstraction, such as those concerned with internal states and abstract verbs per se, were quite well developed in some children. This is particularly the case for mental state verbs. Furthermore, examination of the small percentage of misuses recorded in the data for each child did not indicate atypical development. A surprising result was the inclusion of lexical innovations in the language of some children reflecting quite advanced semantic development. Finally, the ranking of children in terms of their level of semantic development and verb diversity was not predicted

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by chronological age, Performance IQ or MLU. I will address the implications of these results in chapter six.

Chapter 4 Understanding space and time: Preposition learning in children with autism

1. Introduction Similar to research on verb acquisition, studies investigating the development of prepositions in children with autism are quite few in number. The semantic development of prepositions is relevant to the issue of verb acquisition because of the close relationship between these lexical categories. Verbs typically contain restrictions on the types of dependents which may occur within the verb phrase as part of their meanings and, in English, dependents such as arguments (e.g. recipients, beneficiaries) as well as temporal or spatial information is often syntactically realized through prepositional phrases (Blake 1994). There are also syntactic parallels between verbs and prepositions regarding the types of complements they can take (Radford 1988) and the presence of collocations such as look at in children’s early uses of prepositions signifies an even closer alignment with verbs at this stage of language acquisition in typical development. The acquisition of prepositions in children with autism is a little studied area of language acquisition. Much of what is known regarding preposition use in children and adults with autism is to be found in general descriptions of language use. In these accounts, it was observed that prepositions were often omitted, or were used erroneously (Bartak, Rutter, and Cox 1975; Bartolucci, Pierce, and Streiner 1980; Kehrer 1977; Simmons and Baltaxe 1975; Wing 1969). Kanner (1943) noted that single word forms with multiple meanings were difficult for children with autism to acquire and a more recent account of the ability of children with autism to contend with relational meanings suggested that, as a lexical category containing highly polysemous terms, prepositions are extremely problematic for children with autism (Menyuk and Quill 1985). For the present study, I hypothesized that the acquisition of prepositions would proceed according to typical development for highly salient, concrete spatial relations, but as the level of abstraction increased – within the category of spatial as well as for temporal and abstract categories – prepositions would be absent or be used erroneously in the data of the children.

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2. Theoretical background There is some debate as to what exactly constitutes a preposition and how this word class should be defined. Traditional grammars of English define a preposition as the head of a prepositional phrase, illustrated in the example “the tree was in the garden”, while particles in a sentence such as “put your coat on” are classed as adverbial (Quirk et al. 1985). Similarly, the italicized item in the sentence “we went for coffee after the show” is defined as a conjunction. However, as Radford (1988) noted, this type of analysis is problematic inasmuch as terms such as after do not really function as conjunctions (i.e. linking clauses or noun phrases). Therefore, following Emonds (1976) and others (Jackendoff 1973; Langacker 1987; Radford 1988), I use the term “preposition” to include items which function as the head of a prepositional phrase, as well as intransitive prepositions which take no complement, and so-called conjunctions such as before and after. Prepositions which combine with verbs to form phrasal verbs such as hang up in the example “I’m going to hang up the phone” are also considered for the purposes of this study. The semantic categories which provide the framework for this analysis were devised primarily on the basis of previous research into the acquisition of prepositions in typical development (Bowerman and Choi 2003; Durkin 1981; Rice 2003; Tomasello 1987) as well as the general study of prepositions as a lexical class by Landau and Jackendoff (1993). Further sense types not accounted for by previous studies were added where required. Since prepositions are a closed class of words, the difficulties regarding the categorization of “fringe” members encountered in the analysis of verbs did not arise in the distribution of prepositions among the various categories. Table 19 lists the semantic categories analysed with some supporting examples. Other sub-categorizations for the major sense types listed were produced where alternative analyses of the data were investigated. These are outlined in the relevant chapter sections.

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Table 19. Semantic categories of prepositions Sense types Spatial: Spatial locative (SPA-loc) Spatial goal (SPA-goal) Spatial source (SPA-source) Compounds (Compound) Temporal Abstract: Abstract locative (ABS-loc) Abstract goal (ABS-goal) Abstract source (ABS-source) Aspect Change of State Grammatical: Infinitive (INF) Benefactive (BEN) Comitative (COM) Partitive (PART) Instrumental (INST) Purpose (PURP) Attributive (ATT) Dative (DAT) Reason (REASON) Genitive (GEN) Passive (PASS) Misuses

Sample utterances “He’s at the dentist having his teeth fixed” “You had to put, um, a bandaid on” “I got it from the market” “That’s supposed to go on top of that” “I come back at night”; “I’m gonna do blue after this” “We’ve been on a trip” “and then barbie went back to sleep” “no, that was from Christmas” “I mix it up” “it turned into snails” “you have to fix it” “Now santa won’t bring any toys for my brother” “I’m gonna lay down with baby joy” “Here one of the Nemo cards; “a drink of water” “They scratch each other with their claws” “That’s for screwing things” “yeah, with glasses on” “Mommy gave this to me” “I got my fish tank for my birthday” “that was the end of Christmas” “he got caught by a man in the water” “We soon will get married *with (to) her; I wanna play with them *in (on) the counter”

3. Semantic profiles by category 3.1. Spatial Typically developing children begin to use locative prepositions when they reach Stage II of Brown’s (1973) five stages of development (MLU 2.25), or sometime after their second birthday (Leopold 1949). However, even before they are twelve months old, young children’s knowledge of spatial

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relationships is quite advanced (Bowerman 1996; Mandler 1996; Spelke et al. 1992). Thus spatial awareness develops in children well before they begin to encode it linguistically and a desire to communicate this knowledge is apparent in children’s interactions before they have acquired the requisite prepositions (Slobin 1973). According to Piaget and Inhelder (1956) children’s understanding of spatial relationships is derived from their own movement and actions upon objects during the first eighteen months of their lives rather than emerging via the child’s general perception of space. It is for this reason that spatial concepts closely connected with object functions such as containment (in) and support (on) find expression in the early use of prepositions (Clark 1973). The first expression of object location and movement in children’s language occurs in the use of particles or holophrastic utterances including up, down, in and on at the age of fourteen to sixteen months (Bowerman 1996; Rice 2003; Tomasello 1987). Highly salient activities such as the opening and closing of containers, insertion and extraction of objects from containers, and the child’s actions of sitting, climbing and being picked up, as well as events such as the putting on and taking off of clothes are all encoded by these spatial morphemes. In fact Choi and Bowerman (1991) argue that the use of prepositions to encode the movement of an object to another location is developmentally prior to the encoding of static location. However this pattern of development has not been found to be consistent (Rice 2003). In parallel with the order of emergence of spatial concepts determined by Piaget and Inhelder (1956), prepositions expressing containment (in), contiguity and support (on) and occlusion (under) are usually among the first to appear in the language of typically developing children, followed by prepositions which encode proximity (next to, beside, between). Prepositions which express projective relationships (behind, in front of) are the last of the spatial prepositions to be acquired (Bowerman and Choi 2001; Durkin 1981; Johnston and Slobin 1979). The late acquisition of these prepositions is not surprising, since projective relationships are cognitively complex, including constraints on the proximity of the object located by the preposition and its reference object as well as a possible effect of the speaker’s orientation in relation to the objects as part of their meaning. Similar to other lexical categories, prepositions are both overextended (e.g. in for placement of ball between knees) and underextended (used with specific verbs or objects) in the language of children (Bowerman 1996; Rice 2003). The extent to which children with autism acquire terms for spatial concepts is debated. Researchers investigating the language features of children with autism noted that prepositions were often omitted (Bartolucci et al. 1980;

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Kehrer 1977; Wing 1969) or used erroneously in examples such as “you sit for chair in table” (Wing 1969). In a study examining the ability of a child with autism to acquire spatial terms, Churchill (1972) found that although the child successfully learned directional prepositions in an educational setting, he was unable to generalize these terms in novel situations. However, McGee, Krantz, and McClannahan (1985) observed an increase in the use of prepositions in free-play sessions after three children with autism were taught spatial terms in the classroom. Perkins et al. (2006) investigated the use of spatial and temporal terms expressing relational meaning such as “over there” and “in two week’s time” in the language of adults with autism. They found that these terms were used as often as absolute spatial and temporal lexemes such as place names and days of the week. However, erroneous expressions in the data such as the description of breakfast as “a first meal of the day prior to waking” (Perkins et al. 2006: 800) are consistent with the early descriptions of language in individuals with autism discussed above. On the basis of these studies, I anticipated that problems encoding spatial relations would be evident in the data. The percentage of spatial prepositions in the lexicons of each child, divided between the four categories of spatial-goal, spatial-locative, spatial-source and compounds of spatial prepositions, is presented in Table 20. Table 20. Spatial prepositions: Percentage of total preposition use child US

Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

total (%) 100 85.7 55 66.3 66.7 69.9 37.6 50.6 55.9 65.8

SPA-goal 100 57.1 23 58.9 28.9 46.6 26.8 31.8 30.9 37.1

Sub-categories (%) SPA-loc SPA-source 0 28.6 30.9 5.3 37.8 22.5 9.4 15.1 19.7 26.3

0 0 0 0 0 0 0.3 1.4 1.8 0.4

compound 0 0 1.1 2.1 0 0.8 1.1 2.3 3.5 2

As indicated in Table 20, the data from all of the children included examples of spatial prepositions such as “I don’t wanna go in the corner” (B2: 635) and “it’s on the table” (D1: 301). The percentages reveal that spatial senses

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account for all of Stuart’s and over eighty per cent of Rick’s preposition use. For the remaining children, the encoding of spatial relations accounts for between fifty and seventy per cent of their total preposition use, with the exception of Peter whose spatial prepositions made up just over thirty-seven per cent of his total use. This can be accounted for by the large number of instances of the infinitive marker to in Peter’s data which I will address in section 3.4. In accordance with research in typical development (Choi and Bowerman 1991), the majority of children demonstrate a preference for encoding the destination of motion oriented activities over static location illustrated in examples such as “get on bus” (R1: 25) and “hafta go in the truck” (J1: 745). However, in a similar patterning of results to Rice’s (2003) study, the data from Brett and Mark reveal a marginally higher percentage in favour of static location as in utterances such as “I don’t wanna stay in the bathroom” (B2: 1215) and “[she is] standing on diving board” (M3: 736). Table 20 also indicates that only Peter, Liam, Kevin and Joseph marked the spatial source of an object as in the examples “I got it from the market” (L1: 996) and “where’d it come from?” (P3: 630) and the percentage of use for each child is very small. This result is in accordance with typical development in which the preposition from is both acquired late and tends to be used with minimal frequency (Rice 2003). The final category represented in the table is prepositional compounds. Table 20 reveals that seven of the ten children produced compounds, illustrated in the examples “I’m next to S” (K1: 1219) and “…then a bird got Nemo out of the big water tank” (Jo1: 105). The presence of these compounds in the data is interesting as they are arguably more cognitively complex than prepositions which encode just location or the source or goal of movement. Table 21 sets out the use of spatial prepositions for each child, including the number of different preposition types across all categories represented in Table 20. This table reveals there is substantial variation between the children in terms of their ability to encode spatial relationships. The data of Rick, Mark and, in particular, Stuart, contained fewer different spatial terms as indicated in the figures for lexical diversity and their total use of spatial prepositions was much less (Stuart: 2, Rick: 12, and Mark: 30). However, their preposition use is consistent with the stage of language development they have reached as measured by MLU (Stuart: 1.17, Rick: 1.73, and Mark: 1.46). According to Brown (1973), the encoding of even simple spatial relations does not occur systematically until children have reached the next stage of development with an MLU of above two.

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Table 21. Lexical diversity for spatial prepositions

US

Aus.

child Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

lexical diversity 2 7 20 12 7 17 21 27 25 26

basic 9 9 9 9 9 9 9 9 9 9

Semantic complexity proximity projective 8 8 8 8 9 8 8 8 8 8 9 8 9 8 9 8 9 9 9 9

As would be expected with a closed class of lexical items such as prepositions, more advanced conceptual development is reflected in the higher figures for lexical diversity. That is, the absence of terms for proximity in the data of Jack is consistent with his lower score for lexical diversity as compared to the remaining children. Similarly, those children whose data include terms for projective relationships demonstrate a higher lexical diversity. What is particularly noteworthy about the data presented in Table 21 is that the pattern of development in terms of the semantic complexity of prepositions used by each child mirrors the order of emergence argued for typical development (Bowerman and Choi 2001; Johnston and Slobin 1979). That is, children whose data include prepositions for proximity (e.g. “it’s between your knees” (B3: 753)) also produced the basic prepositions, and children who use prepositions expressing projective relationships (e.g. “he [is] behind my chair” (K1: 1698)) have already acquired the basic spatial terms as well as words for proximity. In summary, the data from the current study suggests that not all children with autism experience severe difficulties in the acquisition of spatial prepositions. All of the children produced spatial terms and, in accordance with typical development, spatial categories are well represented in their individual profiles. Moreover, there is no evidence to support the claim of atypical development in the acquisition of spatial terms. While the acquisition process is clearly delayed for some children, others demonstrate quite advanced development in the acquisition of terms denoting proximity and projective relationships.

100 Understanding space and time 3.2. Temporal Typically developing children begin to use temporal prepositions only after spatial terms have emerged. Early uses include metaphorical extensions of the spatial terms in and at which appear in their language at approximately three years of age (Rice 2003). Later metaphorical extensions of spatial terms for temporal uses include for as a marker of duration which appears between three and five years of age, and on as a temporal marker which emerges just before the age of five (Rice 2003). More complex notions of time encoded with the prepositions before and after appear in this same period of development. Clark (1971) argues that young children understand before prior to the comprehension of after and they pass through a developmental stage in which after is interpreted as if it meant before. However, Coker (1978) found no difference in the ability of typically developing children to acquire these prepositions and no intermediate stage in which after is used erroneously. There is little published research regarding the ability of children with autism in the use of temporal prepositions. Nonetheless, as discussed above, previous accounts of the language abilities of individuals with autism indicate they often experience severe difficulties in the acquisition of spatial morphemes. Kanner (1943) noted that the acquisition of multiple meanings for single lexical items is difficult for children with autism and Menyuk and Quill (1985) argue that the highly polysemous nature of prepositions means it is a difficult lexical category for children with autism to acquire. Therefore, it is likely that metaphorical extension of spatial terms will be absent from the language of children with autism, or a pattern of high error rates similar to that found in previous accounts of spatial prepositions will occur. The percentage of temporal prepositions as a proportion of total preposition use for each child is presented in Figure 17. Figure 17 reveals that the data of both Stuart and Rick contained no examples of temporal prepositions. Since spatial prepositions are only just beginning to emerge in the language of these two children, this is not a surprising result. However, as noted in section 3.1, Mark is at the same stage of language development, making the high percentage of temporal terms in his data sample an unexpected result. Close examination of the data reveals there are a total of three instances of the preposition in which are contained within fairly conventionalized expressions about the seasons of the year as in the example “in summer” (M4: 1508) uttered in response to the question “when do we eat watermelon?”. Since Mark’s total token count is forty-five, the three instances of temporal terms account for an unusually high number within his overall preposition use.

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Temporal prepositions: Percentage distribution 8 6.7

7 6 5

3.9

4

2.7

3 2 0.7

1 0

0

0

1

0.9 0.4

0.2

% of preposition lexicon Figure 17. Temporal prepositions: Percentage of total preposition use

Consistent with the order of emergence of temporal prepositions in typical development, the temporal terms of Brett, Jack and Peter are also metaphorical extensions of the spatial preposition in as in the examples “in the winter” (B3: 1291), “in a few minutes” (J4: 742) and “I’ll be back in a minute” (P4: 1671). Interestingly, the data of David and Kevin do not contain temporal uses of spatial terms. However, as David produced only a single instance of the preposition after in the utterance “after David reach up” (D2: 1004), his profile is not suggestive of an atypical process of acquisition. Kevin’s temporal usage consists of three utterances with the preposition before such as “you never did play this game before” (K4: 1804). There is evidence, nonetheless, that Kevin does extend spatial terms to temporal uses in his misuse of at in the utterance “mine’s at September” (K3: 936) in reference to his birthday. The data of Liam and Joseph include metaphorical extensions of

102 Understanding space and time at and the temporal term after and only they encode duration with the preposition for in the utterances “just for a little while” (L2: 709) and “excuse me for a minute” (Jo3: 1005). Liam demonstrates the most advanced development, as his lexicon of temporal terms not only includes all the prepositions discussed thus far, but he is the only child whose data includes temporal uses of the spatial preposition on which appears later in typical development: “on the next day I might tell you” (L2: 132). Similar to spatial prepositions, the data indicates that some children with autism can extend spatial prepositions to encode temporal meanings. While not all children produced temporal terms, the pattern of results is consistent with the process of acquisition in typical development. Moreover, some children demonstrated quite advanced acquisition in the extension of spatial terms which undergo abstraction at a later stage of development. 3.3. Abstract Metaphorical extensions of basic spatial prepositions to abstract concepts can appear as early as two-and-a-half years of age in typical development, or appear somewhat later depending on the abilities of the individual child (Rice 2003). Early uses most often describe the common activity of turning appliances on and off and in conventionalized expressions such as something or someone being “on television” or performing an activity “by oneself” (Rice 2003). Less conventionalized extensions of spatial prepositions begin to appear after the age of three (Rice 2003). As discussed above, Menyuk and Quill (1985) contend that the multiple meanings encoded by prepositions make them a difficult word class to acquire. In particular, abstract meanings are likely to pose significant problems for children with autism (Bartak, Rutter and Cox 1975; Happé 1993). In a study examining language features of individuals with autism, Simmons and Baltaxe (1975: 344) found that an incorrect choice of preposition as in the example “He (the bird) was driven from/under extinction” was a common error in their language samples. Consequently, it is expected that the data from the current study will either contain no examples of abstract prepositions or there will be many instances of incorrect uses. The percentage of abstract prepositions as a proportion of total preposition use for each child is presented in Figure 18.

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Abstract prepositions: Percentage distribution 14 11.8

12

10.5

10

8.5

8

8.5

7.1 5.6

6

5.5 4.4

4

2.9

2 0

0

% of prepositions in lexicon Figure 18. Abstract prepositions: Percentage of total preposition use

As indicated in Figure 18, there are instances of appropriately used abstract prepositions in the data of all children with the exception of Stuart. Moreover, abstract prepositions account for over ten per cent of overall preposition use for Liam and Kevin and between approximately three and nine per cent for the remaining children. Table 22 sets out the use of abstract prepositions for each child, including the number of different preposition types used by each child (lexical diversity) and the percentage distribution across the different subcategories of abstract prepositions analysed. The sub-category of includes various abstract uses of the preposition which do not express quantities, or partitive or genitive relations which are analysed in the following section.

104 Understanding space and time Table 22. Lexical diversity and sub-categories for abstract prepositions lexical child diversity US Stuart 0 Rick 1 Brett 5 Jack 5 Mark 2 Aus. David 4 Peter 5 Liam 14 Kevin 9 Joseph 11

ABSgoal 0 0 66.7 37.5 50 61.5 15.8 27.6 10 21.4

ABSloc 0 100 26.7 62.5 50 15.4 10.5 36.2 32.5 40.5

Sub-categories (%) ABSChange source Aspect of State 0 0 0 0 0 0 0 6.6 0 0 0 0 0 0 0 0 23.1 0 0 31.7 21 0.8 25 0.8 0 37.5 2.5 4.8 4.8 16.6

Of 0 0 0 0 0 0 21 9.6 17.5 11.9

Similar to the categories of spatial and temporal prepositions, Table 22 reveals that there is considerable variation between the children in their extension of spatial words to abstract concepts. Prepositions encoding abstract destinations (ABS-goal) and abstract locations (ABS-loc) occur most frequently in the data of those children who used abstract prepositions. As these categories are also the most well-developed of the spatial concepts, this is not a surprising result. The inclusion of an abstract preposition in the data of Rick is somewhat unexpected given there were no examples of temporal uses. However, the single example is a highly conventionalized use in the utterance “tv’s on” (R1: 682) which may appear before temporal uses in typical development (Rice 2003). Similarly, the two abstract prepositions in Mark’s data are conventionalized uses as in the example “do it put tape on here” (M4: 286). General features of the data are that the spatial prepositions in and on are most commonly extended to metaphoric uses and many abstract uses revolve around the following concepts: being on television, as in the examples “on channel eleven” (J2: 640) and “it’s mummy in the camera” (D3: 1246); and, the operation of appliances as in the utterances “need to turn the fan on” (B1: 665) and “oh, I turn it off” (K4: 277) in reference to an electronic game. However, the data of Peter, Liam, Kevin and Joseph contain many, less conventionalized expressions such as “my dad has told me all about it” (K4: 1703) and “that’s me thinking in your head” (L3: 236) as well as change of state uses as in “it turned into snails” (P2: 209). Only the data of Liam and Joseph include instances encoding an abstract source illustrated in the examples “no, that was from Christmas” (L4: 1054) and “from the cold wind” (Jo4: 871) where Joseph was explaining how he got sores on his legs. Since

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spatial uses of the preposition from emerge later in typical development, the absence of expression of abstract sources from the majority of children is a consistent result. An interesting feature of the data is that aspectual uses of prepositions as verb particles feature strongly in the data of David, Peter, Liam, Kevin and Joseph as in the examples “I mix it up” (D1: 1417) and “maybe we have to check all these to full them up” (K1: 2408). Previous research into the acquisition of verb particles has found that the aspectual use of particles such as in the examples listed above emerges somewhere between two and three years of age in typical development, (Jeschull 2003). However, the appearance of lexical aspect in the data of some children is somewhat surprising when considered in the context of the documented difficulties of children with autism in regard to semantically abstract concepts. In particular, Menyuk and Quill’s (1985) assertion that understanding the complexity of the semantic relationship between a verb particle and its verb is extremely problematic for children with autism. I will address this feature of the data in more detail below. Consistent with the findings on the use of spatial and temporal prepositions, the profile of use for abstract prepositions by the children did not reveal any evidence of atypical development. The pattern of results for each child is concordant with the order of emergence documented for typical development. Moreover, the metaphorical extensions of the spatial terms by some children displays a level of semantic development not predicted by previous accounts of the abilities of children with autism. 3.4. Grammatical Studies of the acquisition of prepositions encoding grammatical relations in typical development reveal there is considerable variation in regard to the order in which these categories emerge and the ages at which acquisition takes place (Rice 2003; Tomasello 1987). However, there are a few consistent patterns such as the early emergence of the infinitive marker to, as well as comitative uses of with as in “play with me” and expression of the benefactive as in the example “I made this for you”. Conversely, passive constructions with an overt by-phrase (e.g. “the dog was chased by the boy”), genitive uses of the preposition of (e.g. “that book of mine”) and the dative use of to (e.g. “she gave the cake to the lady”) are among the last prepositions to be acquired (Rice 2003; Tomasello 1987). Difficulties in the acquisition of these grammatical relations are reflected in the errors that occur in the course of

106 Understanding space and time development. Clark and Carpenter (1989: 1) found that early expression of oblique agents occurred with the preposition from as in the utterance “I was caught from you before”, before changing to the correct use of by. Tomasello (1987: 87) recorded for as the preposition first used to encode a recipient illustrated in the example “Timothy gave that necklace for me”, before a shift to the correct preposition to occurred. Menyuk and Quill (1985) predict that highly abstract uses of prepositions will be difficult for children with autism and prepositions are often omitted in language samples of children with autism (Kehrer 1977; Bartolucci et al. 1980). These findings suggest that encoding of grammatical relations is likely to be absent or erroneous in the language of these children. Table 23 presents the grammatical use of prepositions which were correctly encoded in the language samples of the children. Table 23. Grammatical prepositions

COM

PART

INST

PURP

ATT

DAT

REAS

GEN

PASS

US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

BEN

child

INF

Grammatical relations (%)

8 8 9 9 8 9 9 9 9 9

8 9 8 8 8 9 9 9 9 9

8 8 9 9 8 8 9 9 9 9

8 8 9 8 8 9 9 9 9 9

8 8 9 9 9 9 9 9 9 9

8 8 8 9 8 8 9 9 9 9

8 8 9 8 8 8 8 9 9 9

8 8 9 8 9 8 9 9 9 9

8 8 9 9 8 8 9 9 9 9

8 8 8 8 8 8 8 9 8 9

8 8 8 8 8 8 8 8 8 9

As indicated in Table 23, Stuart did not encode any grammatical relations and Rick’s data contained a single example of a benefactive relation in the example “make a tree for you” (R4: 1100). Mark’s profile is similarly sparse, with a small number of instrumental uses of the preposition with as in the example “play with a kite” (M4: 1020) and the somewhat surprising inclusion of two utterances marking a recipient as in “gave it to you” (M3: 1478). However, close examination of the data reveals that the recipient is actually Mark, making it unclear whether the utterance is genuinely spontaneous or, in fact, echolalic. The encoding of grammatical relations is better developed in the language of Jack, Brett and David. While the total number of grammatical

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prepositions in Jack’s data is small, the range of relations expressed is somewhat broader, including purpose – “that’s for Christmas” (J1: 641) and comitative – “I’m gonna lay down with baby joy” (J3: 1055). The grammatical categories encoded by David and, especially, Brett are used with greater frequency and include partitive relations as in the example “that’s piece of play doh” (D4: 1450) and reason, illustrated in the utterance “for birthday” (B3: 803) explaining why his nana was coming to visit. Peter and Kevin encode the majority of grammatical relations represented in Table 23 including attributive uses of with as in the example “a racing car with eyes” (K1: 360). A striking feature of Peter’s data is the extremely high rate of use for the infinitive marker to (49.3% of total preposition use). However, this phenomenon has been observed in the language of typically developing children (Rice 2003). Liam and Joseph demonstrate the most advanced development. They are the only children to encode possession with the genitive of illustrated in the example “that was the end of Christmas” (L4: 534) and only the data of Joseph included passive constructions with a byphrase as in the utterance “he got caught by a man in the water” (Jo1: 21). The data from the present study reveals that, inasmuch as there is a pattern, the expression of grammatical relations appears to develop in accordance with typical development. That is, the infinitive to, as well as comitative and benefactive relations emerge early and the dative to, genitive of and by-phrase marking the oblique agent of a passive construction all appear later. In particular, the use of prepositions to encode highly abstract relations by many of the children is a result not predicted by previous accounts of the language of children with autism. 3.5. Misuses Within the small number of studies which have considered in detail the acquisition of prepositions in typically developing children, there appears to be considerable variation in regard to the extent to which misuses (or nonadult uses) occur. While Mandler (1996) claims that the basic spatial relations of containment and support are learned virtually error free, misuses accounted for seven per cent of utterances containing the preposition in produced by the typically developing child in Tomasello’s (1987) study. Similarly, there was considerable variation between the children in Rice’s (2003) study in regard to the rate of misuses for the preposition at, with one child producing misuses at a rate of fourteen per cent in comparison to the other child’s error free

108 Understanding space and time production. However, the rate of misuses across the prepositions examined in Tomasello’s (1987) and Rice’s (2003) studies were generally very low. There is greater consensus in regard to nature and extent of misuses of prepositions in the language of children with autism. Previous studies have consistently found that children with autism demonstrate poor ability in the use of prepositions (Bartolucci et al. 1980; Churchill 1972; Menyuk and Quill 1985; Wing 1969). Figure 19 presents the percentage of prepositions coded as misuses in the data of each child from the current study. Misuses: Percentage distribution 16

14.4

14 11.1

12 10 8 6 4

1.9

1.1

2 0

4.4

3.7

0

2

1.4

0

% of misuses Figure 19. Misuses: Percentage of total preposition use

In contrast to earlier accounts of preposition use in children with autism, Figure 19 reveals that, with the exception of Mark and David, the misuses accounted for only four and a half per cent or less of the total preposition use of each child. While this is somewhat higher than the percentages of misuses generally recorded in studies of typically developing children, the percentages

Detailed examination of in, on, up, and at

109

are lower than would be expected on the basis of previous research in autism. Thus, the children from the current study demonstrate that it is possible for children with autism to acquire spatial terms and extend their use to a range of contexts without resulting in large numbers of misuses. 4. Detailed examination of the prepositions in, on, up, and at 4. Detailed examination of in, on, up, and at This section offers a detailed analysis of the prepositions in, on, up and at. These prepositions were chosen because of their early emergence in typical development, as well as the fact that the token counts of most children were large enough to warrant closer examination. The prepositions were considered along the following parameters: the distribution among the different sense types encoded in the data in the context of acquisition in typical development; the proportion of misuses in terms of total preposition use and the nature of these non-adult productions; the extent to which the prepositions have been generalized within the various semantic domains in which they occur; and the extent to which the transferral of objects as initiated by other people have been encoded. 4.1. In The preposition in is one of the earliest to emerge in the language of typically developing children. Spatial relations are encoded initially and the preposition is often used as a particle or as a holophrastic utterance, before it occurs in full prepositional phrases (Tomasello 1987). There is evidence in the language of typically developing children that the preposition is often underextended. That is, the types of activities and events where location is overtly mentioned are initially highly restricted resulting in the preposition in being used almost exclusively to talk about activities such as putting objects in containers (Rice 2003). Spatial prepositions may also be overextended, such as the use of in to encode proximity locations such as the placement of a ball between the knees (Bowerman 1996). The preposition in is readily extended to encode location in time in typical development as well as abstract locations. The various uses of the preposition in as produced by the children of the current study are presented in Table 24.

110 Understanding space and time Table 24. Semantic categories for the preposition in

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

SPAloc 0 100 42.2 21.4 50 29.5 52.7 45.9 41.5 56.9

SPAgoal 0 0 37.8 71.4 18.8 32.6 34.5 37 44.9 36.6

ABSloc 0 0 0 0 6.3 6.3 0 8.2 3.4 6.5

Sub-categories (%) Change of State INST Temporal 0 0 0 0 0 0 0 0 4.4 0 0 7.2 0 0 18.6 0 0 0 3.6 0 1.8 0 0 7.4 3.4 3.4 0 0 0 0

Misuse 0 0 15.6 0 6.3 31.6 7.4 1.5 3.4 0

As shown in Table 24, Stuart’s data did not contain any uses of the preposition in. For the remaining children, it is clear that the preposition was used predominantly for spatial relations, and static location (SPA-loc) as in the example “it’s, um, in here” (D3: 785) was encoded more frequently than destination (SPA-goal) as in “you go in the gate” (B1: 989) for over half of the children. Temporal uses are present in the data of Brett, Jack, Mark, Peter and Liam including references to immediate time such as “in a few minutes” (J4: 742) and references to the months of the year as in the example “in June” (M4: 1517). Interestingly, there are no temporal uses in the data of David, Kevin and Joseph and yet they are among those children whose data includes references to abstract locations. However, temporal uses do not always precede abstract uses in typical development (Rice 2003). Extensions to abstract locations include examples such as “Melanie in the camera” (D3: 1378) and “what it’s called in speech” (L2: 1271). Other abstract uses include changes of state by Peter and Kevin in the utterances “you’re going to break in half” (P3: 1458) and “fold this one in half” (K4: 1683). The data of Kevin also includes an example coded as instrumental (INST) found in the utterance “I write in pencil” (K1: 2352). Table 24 reveals that for some children, the percentage of misuses in their data was quite large while others had either none or very few. The most common type of misuse is the confusion of the prepositions in and on. Kevin’s two instances are of this nature resulting in utterances such as “no, this goes on the bag” (K4: 1656). It appears that David uses the preposition in as a general preposition, reinforced by the extremely high number of misuses in his data. The preposition has been overextended to more complex spatial relations

Detailed examination of in, on, up, and at

111

such as source illustrated in the example “I’m gonna get some in the tap” (D2: 312) and the projective relation behind, as in the utterance “it go in the fence” (D1: 1598). Similarly, Brett produces the utterance “look in the flying glass” (B4: 958) which, although semantically plausible, is expressed by the preposition through in adult usage. However, for both David and Brett, the majority of misuses occur where adult usage requires the preposition on leading to utterances such as “I want the gate in the placemats” (B1: 400), where the context makes clear that Brett is expressing a desire for the gate to be placed on the placemats, and “I put in the table” (D2: 183). This confusion of in and on is interesting since it is claimed that typically developing children tend to learn these prepositions virtually error free (Mandler 1996). This suggests that, at least for some children with autism, the acquisition of spatial morphemes is not a straightforward process. Indeed, there is evidence in the data to indicate that David is in the process of reorganising the lexical encoding of spatial domains. Often he begins with the correct preposition and then reverts to or adds in to the utterance as in “stick it on, in the arm” and the following exchange illustrates his awareness of this process. The final two lines are spoken very quietly to himself in the video as though he is taking note of the correct use: (1)

Child: Researcher: Researcher: Child: Child:

sit, sit on the, in the, in the bottom. okay, I'll sit on my bottom. then what do I have to do? sit on the bottom. okay. (D4: 681-685)

The misuses recorded in Peter’s data reveal that he is experiencing difficulty encoding spatial source. Despite the correct use of the preposition from on a number of occasions, he produces utterances such as “is it coming out in there?” (P3: 291). Mark and Liam’s data contains only one and two misuses, respectively, relating to the inappropriate insertion of in as in the example “in the ball” (M3: 326) uttered in response to the question “what is he throwing?”. The following table presents the range of verbs used with the preposition in, where verbs which feature strongly are indicated separately and those verbs with minimal use are presented collectively in the column labelled “other”. The specific number of verbs used with the preposition in by each child is also represented in the column labelled lexical diversity.

112 Understanding space and time Table 25. Verb use with the preposition in lexical child diversity bare PP US Stuart 0 0 Rick 0 100 Brett 17 10.5 Jack 6 21.4 Mark 1 86.7 Aus. David 14 21.9 Peter 17 7.8 Liam 29 6.8 Kevin 8 10.7 Joseph 27 4.3

put 0 0 7.9 14.3 13.3 15.6 25.5 27.8 32.1 14

Verbs (%) go be get 0 0 0 0 0 0 28.9 7.9 0 14.3 0 35.7 0 0 0 18.8 18.8 0 9.8 23.5 0 4.5 22.6 3 7.1 21.4 10.7 8.6 16.1 4.3

have 0 0 0 0 0 0 0 10.5 0 12.9

other 0 0 44.8 14.3 0 24.9 33.4 24.8 18 39.8

Table 25 indicates that for the majority of children, the preposition in has been extended to use with a range of verbs. Not surprisingly, verbs such as put and go for dynamic location and be for static location account for a large percentage of verbs used in combination with this preposition, illustrated in the following examples: “let’s put it in here” (K2:802), “don’t go in the gate” (B1: 184), and “there’s two ducks in there” (Jo1: 833). As general purpose verbs, they are likely to be used with greater frequency and they are also the verbs which occur in early production of prepositions (Rice 2003). For Rick and Mark, in appears either exclusively or predominantly in bare prepositional phrases such as “in the water” (R1: 1042) which are most often uttered in response to a question. However, many of the children encode containment – both concrete and abstract – with quite a variety of verbs as indicated in the lexical diversity column of Table 25. This suggests a generalized understanding of the preposition not restricted to specific actions or events for these children. Table 26 sets out the range of subjects whose spatial interactions are encoded by the children. The transferral of objects to another location as initiated by the children, themselves, accounts for a large percentage of constructions expressing containment. That is, utterances such as “I throw in the rubbish” (D2: 658) feature strongly in the data of all children. As indicated in Table 26, over half of the total number of instances centre on the child’s actions for Stuart, Rick, Brett and David and just under half for Liam, Kevin and Joseph. However, the figures also reveal that, with the exception of Stuart, all of the children extend the preposition in to talk about the actions of others and the static locations of people and objects as in the utterances “he’s in the chair” (B4: 990), “you

Detailed examination of in, on, up, and at

113

could put this in your cupboard” (L2: 461) and “mine’s in the middle” (K1: 1419). Table 26. Subject use with the preposition in 1 US

Aus.

child Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

Sg 62.5 54.8 64.9 34.2 37.4 61.3 24.8 41.2 42.7 42.2

Pl 0 0 3.1 9.2 2.2 0.9 13 8.3 11.5 4

Subject use (%) 2 3 Sg Pl Sg 0 0 0 19.4 0 22.6 12.9 0 11.6 15.8 0 23.7 21.9 0 30.8 11.3 0 22.2 30.8 0 29.2 19.5 0 19.3 25.2 0 16.5 28.5 0 19.5

Pl 0 0 3.1 7.9 4.4 1.9 0.9 7.5 1.9 5.1

? 37.5 3.2 4.4 9.2 3.3 2.4 1.3 4.2 2.2 0.7

In summary, the data indicates that, for those children whose data contains more than isolated uses, the preposition in emerges according to the same pattern of development described for typically developing children. The predominant uses were to encode spatial relations with abstract and temporal uses only appearing in the data of children already encoding spatial relations. Similar to typically developing children, there is evidence of underextension in the frequent use of the preposition with verbs such as go and get and, in particular, the verb put. The percentage of misuses of the preposition in the data of some children is considerably higher than the figures from studies of typically developing children (Rice 2003; Tomasello 1987). This indicates that the acquisition of spatial concepts may be more difficult for children with autism. Nonetheless, the nature of these misuses also offers support to the claim that semantic development within the various categories which comprise the spatial domain is taking place in the language of the children from the current study. Moreover, there is evidence that for some children, acquisition of the preposition in is quite well developed in the variety of meanings expressed, the range of verbs used and the extension of the preposition to subjects other than the speaker.

114 Understanding space and time 4.2. On The preposition on is also among the early prepositions to emerge in the language of typically developing children, initially in holophrastic and verb particle uses before occurring as the head of a prepositional phrase (Tomasello 1987). As with the preposition in, spatial uses are developmentally prior to temporal and abstract uses. However conventional abstract expressions relating to the operation of household appliances and light switches emerge quite quickly (Rice 2003). Highly salient activities such as the putting on of clothes account for early uses of the preposition before it is generalized to other notions of support (Rice 2003). Temporal uses of the preposition on are later to emerge in typical development than for in. The different semantic categories for the preposition on as identified in the data are presented in Table 27. Table 27. Semantic categories for the preposition on child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

SPA-loc 0 50 31 33.4 40 36.4 22.2 31.5 54.9 41.7

SPA-goal 100 25 31 33.3 33.4 50 63.9 32.3 37.3 46.4

Sub-categories (%) turn-on ABS-loc 0 0 25 0 20.7 17.3 0 33.3 6.6 0 9.1 0 11.1 2.8 6.4 21 0 1.9 5.9 2.4

TEMP 0 0 0 0 0 0 0 3.2 0 0

Misuse 0 0 0 0 20 4.5 0 5.6 5.9 3.6

Table 27 reveals that Stuart’s use of the preposition on is exclusively spatial and the single instance recorded in his data encodes destination. Rick, Mark and David’s data include predominantly spatial senses of the preposition with Rick and Mark encoding more goal-directed locations as in the utterance “climbing on” (M3: 802) and David encoding a higher percentage of static locations such as “it’s on the table” (D1: 301). Abstract uses for these children are the early emerging references to the operation of appliances as in the example “tv’s on” (R1: 682). The use of on for the remaining children also contains high percentages of spatial uses, particularly for Peter, Kevin and Joseph. Similar to Rice’s (2003) study, there is no clear preference for encoding destination over static location. There is a surprising absence of

Detailed examination of in, on, up, and at

115

preposition use relating to the turning on of appliances in the data of Jack and Kevin, since they do encode abstract locations. However, these abstract locations predominantly refer to people or objects being on television or on computer illustrated in the examples “on channel eleven” (J2: 640) and “[Bob the Builder is] on the computer as well” (K3: 24). In accordance with typical development, there are examples of on in the context of turning on appliances in the data of Rick and Mark but not abstract locations. Brett, Jack, Peter, Liam, Kevin and Joseph all encode abstract locations illustrated in the examples “we were on holidays” (L1: 642) and “on the other way back” (Jo4: 891). While Jack’s low token count (6) means his high percentage of abstract prepositions is difficult to comment on, the higher token counts of Brett (29) and Liam (117) make their high percentage of abstract locations a more interesting result. Their data includes conventionalized uses of the preposition on, such as being on camera, as well as more abstract locations, illustrated in the examples “on a bright sunny day” (B4: 1064) and “on the way home” (L2: 1302). As noted in section 3.2, the advanced development of Liam is reflected in the temporal use of the preposition on in the utterance “on the next day I might tell you” (L2: 132). With the exception of Mark, the percentage of misuses in the data of the children is quite low. Similar to the pattern for the preposition in, confusion of in and on is a common misuse. Less prototypical scenarios of containment often result in non-adult uses such as the following examples: “and we drived off on a big car” (L2: 1508) presumably related to other conventionalized uses of on as in “on a train”; and “I got a cubby house on my tree” (Y2: 1744). Similarly, Liam uses on in abstract contexts which by convention require the preposition at as in the example “on Christmastime I saw the Christmas carols” (L4: 455). David overextends the preposition on in the example “I get on” (D1: 1345), uttered as he stepped over the camera tripod, and Kevin produces a small number of semantically plausible but non-adult uses of the preposition such as “I smash on you” (K3: 400). Mark appears to be having the greatest difficulty with the preposition as his misuses also occur with simple spatial locations such as his answer “on cup” (M3: 1802) in response to the question “where do you want me to put the soda?”. However, he does produce “in cup” (M3: 1814) a little later in the conversation without any overt correction from his mother. The remaining type of misuses may be classed as both semantic and syntactic, where the inclusion of the preposition is unnecessary, as in the example “I’m on next to Susan” (K3: 1259) and Liam’s use of “back on” in utterances such as “he’s back on in the house” (L3: 670). The following table presents the range of verbs used with the preposition on, including frequently

116 Understanding space and time used verbs and the specific number of verbs used by each child (lexical diversity). Table 28. Verb use with the preposition on lexical child diversity bare PP US Stuart 1 0 Rick 2 25 Brett 11 13.8 Jack 2 66.6 Mark 6 50 Aus. David 8 9.6 Peter 13 16.7 Liam 26 8.5 Kevin 12 16.7 Joseph 25 9.9

put 100 0 17.2 16.7 8.3 14.3 38.9 21.4 8.3 11.1

Verbs (%) go be get 0 0 0 0 50 25 20.7 10.3 0 0 0 0 8.3 0 0 14.3 19 23.8 2.8 0 0 8.5 18.8 4.3 8.3 25 18.7 16 14.8 12.3

have 0 0 10.3 0 0 0 5.5 6 6.3 6.2

other 0 0 27.7 16.7 33.4 19 36.1 32.5 16.7 29.7

Table 28 reveals there is considerable variation between children in terms of the extent to which the preposition on has been generalized. Similar to the preposition in, the general purpose verbs such as put, get and go occur more often in the expression of destination and be is frequently used in the describing of static location. Stuart’s single example occurs with the verb put and, consistent with the high percentage of static locations encoded, the most frequently used verb in Rick’s data is be, followed by get for spatial goal uses such as “get on bus” (R1: 25). For Jack and Mark, bare prepositional phrases such as “on the road” (J3: 142) account for a large percentage of instances. However, evidence that the remaining children have generalized the preposition to use with other verbs is found in the more even distribution among the general purpose verbs, the higher percentages in the “other” column and the number of different verbs used as indicated by lexical diversity. This is particularly the case for Liam and Joseph whose data includes more semantically constrained examples such as “see her dancing on that thing” (L4: 572) and “you climb on the fence” (Jo3: 1507). Table 29 presents the different subjects whose interaction with objects and space are encoded by the children.

Detailed examination of in, on, up, and at

117

Table 29. Subject use with the preposition on 1 US

Aus.

child Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

Sg 0 0 58.6 33.3 8.3 38.1 27.8 35 18.8 30.9

Pl 0 0 0 16.7 0 0 5.6 9.4 2.1 0

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 75 0 3.5 0 24.1 3.5 0 0 33.3 16.7 16.7 0 66.7 0 0 0 57.1 0 30.5 0 22.2 5.6 12.8 0 29.1 7.7 16.7 0 54.1 8.3 25.9 0 27.2 11.1

? 100 25 10.3 0 8.3 4.8 8.3 6 0 4.9

As indicated in Table 29, the children own actions upon objects and the resulting change in location account for a large number of instances in the data of Brett, Jack, David, Peter, Liam and Joseph, illustrated in the following examples: “I’m gonna go on the Ferris wheel” (B3: 530); “I put on the pyjamas” (D1: 1744); and “I sit on you” (P2: 1394). The intended subject in the single instance recorded in Stuart’s data is ambiguous, but it is likely that Stuart is referring to himself in the utterance “put a block on” (S3: 517). The high percentage of third person singular subjects in the data of Rick and Mark is due to the high number of constructions describing the locative states of other people or objects. However, Table 29 also indicates that the majority of children extend the preposition to describe the transferral of objects initiated by other people as in the examples “you have to put me on top” (K1: 1181), “and they put it back on the bench” (L2: 1665) and “you have to go on these boats all by yourself” (Jo2: 432). Collectively, the data from each child reveals that the preposition on develops in accordance with the process of acquisition documented for typically developing children. That is, spatial uses are primary and account for the majority of instances, while abstract uses relating to the operation of appliances or their operative states appear before abstract locations are encoded. Similarly, temporal uses only appear in the data of the child who demonstrates the most advanced development. While the rate of misuses for this preposition is smaller than for the preposition in, the percentages are still slightly higher than previous studies of typically developing children (Rice 2003; Tomasello 1987). However, the nature of the misuses provide further evidence of the development of category structure, since the majority of

118 Understanding space and time misuses are overextensions in less prototypical contexts. For those children whose data contain more than a few tokens, the more even distribution across a range of verbs and extension to subjects other than the speaker indicates that the preposition has been generalized. 4.3. Up The preposition up is also one of the earliest spatial terms to be acquired in typical development. Similar to the course of development for in and on, early uses of up are holophrastic or in frequently used combinations such as “up here” before appearing in prepositional phrases (Tomasello 1987). The preposition up also appears as a verb particle whose meaning may be spatial (e.g. “pick up”) but, as discussed in section 3.3, it may also carry an aspectual meaning as in the example “drink up” (Lindner 1983). While spatial meanings of up functioning as a verb particle are among the earliest uses of the preposition (Tomasello 1987), aspectual uses appear in the language of typically developing children somewhere between two and three years of age (Jeschull 2003). The distribution of spatial and aspectual instances of the preposition up within the data of each child is presented in Table 30. Table 30. Semantic categories for the preposition up child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

SPA-loc 0 0 0 0 0 14.3 2.7 22.9 8.3 27.3

Sub-categories (%) SPA-goal Aspect 100 0 100 0 80 20 100 0 100 0 71.4 10.7 81.1 16.2 37.8 35.2 29.2 62.5 54.5 18.2

Misuse 0 0 0 0 0 3.6 0 4.1 0 0

Table 30 reveals that the majority of the children principally use the preposition up to encode the destination of people or objects, illustrated in the utterances “sit up” (S1: 347) and “he’s going up those stairs” (J2: 597). Only the Australian children encode static location as in the examples “he’s gonna play up here” (P3: 707) and “see those up there?” (Jo3: 1371). As noted

Detailed examination of in, on, up, and at

119

earlier, the most interesting feature of the data is the inclusion of aspectual uses by Brett from the US data and all of the Australian children. These uses include fairly conventionalized expressions such as “boo wake up soon” (D1: 597) and “wanna mix it up” (B3: 935), but also utterances such as “I sucked it all up” (K3: 2357) and “she wiped it up” (L2: 408) which provide evidence that the telic meaning of the preposition has been acquired and not simply a set of fixed expressions. Menyuk and Quill (1985) argue that the various notions of directionality expressed when up functions as a verb particle make the acquisition of this type of preposition use extremely difficult for children with autism. The presence, then, of these highly abstract uses of the preposition to express completion of action is a particularly noteworthy result. As indicated in Table 30, there are only instances of misuses in the data of David and Liam and the percentages are quite low. The single misuse produced by David occurs in a less prototypical “under” scenario, where he says “up here” before placing a picture card at the base of another card (D3: 1548). Similarly, Liam uses up in a less prototypical scenario of containment to produce the utterance “putting a spoon up his ear” (L3: 229). The other misuses for Liam include what appears to be a splicing of thoughts as he is commenting on his mother’s height and the location of the shelf he is trying to reach, resulting in the comment “mum, you’re much taller up here” (L1: 945), and an interesting overextension of the aspectual up in the utterance “I dig up the hole” (L1: 1018). The following table presents the range of verbs used with the preposition up, including frequently used verbs and the specific number of verbs used by each child (lexical diversity). Table 31. Verb use with the preposition up lexical child diversity US Stuart 1 Rick 0 Brett 3 Jack 4 Mark 1 Aus. David 12 Peter 13 Liam 34 Kevin 10 Joseph 8

bare PP 0 100 0 0 0 33.3 2.7 1.4 4.2 18.2

put 0 0 0 0 0 7.4 16.2 12.7 0 0

Verbs (%) go wake 0 0 0 0 40 0 42.8 0 0 0 18.6 7.4 32.4 5.4 7 4.2 29.2 0 0 9.1

pick 0 0 40 0 0 3.7 13.6 0 0 9.1

mix 0 0 20 0 0 3.7 0 5.6 4.2 0

other 100 0 0 57.2 100 25.9 29.7 69.1 62.4 63.6

120 Understanding space and time The small set of verbs with which the preposition up is used in the data of the US children and the small token counts (maximum of seven) means that there is little to say about the extent to which the preposition has been generalized. However, consistent with the prevalence of uses encoding directionality, the verb go features in the data of both Brett and Jack, illustrated in the examples “I don’t wanna go up there” (B3: 1354) and “going up those stairs” (J2: 331). Similarly, Rick utters the prepositional phrase “up stairs” (R1: 933) while making his toy cat walk up the stairs. Since Stuart is asked to sit up quite frequently by his mother, it is not surprising that the single spontaneous usage in his data – “sit up” (S1: 374) – encodes this experientially basic act. For the Australian children, with particular reference to Liam, the evidence is clearer that the preposition up has been generalized to occur with a range of different verbs. This is reflected in the greater distribution across the higher frequency verbs, and the high percentages for some children in the “other” column in combination with the lexical diversity figures. These children use the preposition up with a number of different verbs which have “motion” as a meaning component as illustrated in the examples “my leg is going to come up and get me” (P4: 802), “see, it lifts me up” (L2: 706) and “I’m climbing up here” (Jo3: 1484). As noted above, the aspectual use of up also occurs in a number of different constructions. The following table presents the range of subjects whose spatial location or directional activities were encoded by the children. Table 32. Subject use with the preposition up

1 US

Aus.

child Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

Sg 100 0 60 42.9 0 44.4 21.6 38 37.5 27.3

Pl 0 0 0 0 0 3.7 10.8 7 8.3 0

Subject use (%) 2 3 Sg Pl Sg 0 0 0 0 0 100 20 0 0 0 0 57.1 0 0 100 0 0 48.2 27 0 40.6 9.9 0 31 16.7 0 25 18.2 0 45.4

Pl 0 0 20 0 0 0 0 9.9 8.3 0

? 0 0 0 0 0 3.7 0 4.2 4.2 9.1

Detailed examination of in, on, up, and at

121

Despite the limited number of examples in the data of some children, Table 32 indicates that the preposition up is often used with more than just the speaker as subject. Given his limited development, it is not surprising that Stuart is the implied subject in his single utterance. Similarly, while Rick is describing the action of another in his single use, examination of the context reveals that he is controlling the action as he makes his toy cat walk up the stairs. Mark’s only example is his response “hanging up” (M2: 1079) to the question “what are they doing with the Christmas cards?”, where he is not required to overtly code the subject. For the remaining children, the spatial-goal constructions are extended to include the goal-directed activities of other people in examples such as “white animals go up the gate” (B1: 130). Likewise, static location illustrated in the example “more Thomas up there” (Jo2: 817), as well as aspectual uses such as “he has to fix up the roof now” (L2: 1467) and “we gotta pack this one up” (K2: 2064), are used productively by the Australian children with people and objects other than the speaker as the subject. As with the prepositions in and on, the semantic development of the preposition up is consistent with the acquisition process detailed for typically developing children. Directionality is clearly a more salient concept than static location for the children, with the majority of instances encoding destination. While misuses of the preposition are not recorded in the acquisition process of typical development (Tomasello 1987), the percentage of misuses in the current study are very small. Moreover, these misuses follow the pattern discussed above for in and on, in that they are either overextensions in less prototypical contexts or simply performance errors. Similar to typically developing children, there is evidence of underextension with the verb go in the data of Brett and Jack. In contrast, the Australian children encode directionality with a range of verbs and the preposition is used to describe the activities and states of other persons. This, in combination with the aspectual use of the preposition, points to quite advanced development for at least some children. 4.4. At The final preposition to be considered in detail is at, which also appears early in typical development. It is initially used in the collocation “look at” from somewhere between the ages of two and two-and-a-half years (Rice 2003; Tomasello 1987). This expression provides young children with a useful pragmatic device to gain the attention of others, and remains a predominant usage of the preposition, even after more generalized uses encoding static

122 Understanding space and time locations begin (Rice 2003; Tomasello 1987). Metaphorical extensions of at develop quickly, with temporal and abstract uses appearing in the language of typically developing children at approximately three years of age (Rice 2003) or even earlier (Tomasello 1987). The various semantic categories of the preposition at as produced by the children of the current study are presented in Table 33. Table 33. Semantic categories for the preposition at

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

SPAloc 0 0 29.7 0 50 50 0 44.1 33.4 73.9

SPAgoal 0 0 64.9 0 25 25 84.6 26.4 33.3 4.3

Sub-categories (%) ABSABSloc goal 0 0 0 0 0 0 100 0 0 0 0 0 0 0 5.9 11.8 0 0 8.7 0

TEMP 0 0 0 0 0 0 0 11.8 0 13.1

Misuse 0 0 5.4 0 25 25 15.4 0 33.3 0

Table 33 reveals that there were no instances of the preposition at in the data of either Stuart or Rick. The token counts for Jack, Mark and David were very low (four or less) and use of the preposition by Peter and Kevin was also quite modest (token counts of thirteen and eleven, respectively). In contrast, the data of Brett, Liam and Joseph contained considerably more instances of at (Brett = 37; L = 34; Y = 23). For the majority of children whose lexicon included at, the preposition was used exclusively to encode spatial relations, as in the examples “at the museum” (M1: 400) and “I do play at kitchen” (D1: 1792) uttered in reference to a toy kitchen. As discussed previously, David has a tendency to use the preposition in as a general purpose spatial marker. In terms of his acquisition of the preposition at, it is worth noting that he occasionally begins with appropriate use of at, before incorrectly reverting to in to complete his utterance: (2)

Mother: Child:

where’s David? he’s at, in, in, home (D2: 458)

Detailed examination of in, on, up, and at

123

Interestingly, Jack’s preposition use is exclusively abstract with no spatial uses as in the utterance “see you tomorrow at lunch” (J2: 310). However the status of these instances is ambiguous: while the contexts in which they occur does not preclude them from being analysed as spontaneous utterances, it may be the case they are examples of delayed echolalia, since the phrase occurs elsewhere in utterances which are clearly examples of echolalia. Only the data of Liam and Joseph contain abstract and temporal uses as well as spatial, illustrated in the utterances “we can see the fish at night” (L1: 765) and “you can’t trick me at all” (Jo1: 945). There are misuses in the data of five of the children. While the actual number of misuses is not high, the percentages indicate that in the context of their overall use of the preposition at, misuses account for a large proportion for many children. Nonetheless, this is not dissimilar to Rice’s study of two typically developing children in which the misuses for one child were fourteen per cent of his total use for the preposition at (Rice 2003). Examination of the data reveals that the majority of the misuses relate to at being used as an expression of movement towards a location which, in adult use, would be expressed by the preposition to. This occurs in fairly straightforward contexts such as the example “I come at Susan’s” (D2: 470), less concrete notions of directionality such as Mark’s response – “at Florida” (M1: 473) – to the question “where are we going on the big airplane?”, and, in the case of Peter, simultaneous expression of location and direction in the utterance “the tractor is backed at to home” (P2: 1303). A small number of errors are syntactic as in the utterance “I have to be at resting” (P3: 1518) and Kevin overextends at to metaphorical contexts of containment and support as in the example “mine’s at September” (K3: 936) in which he is talking about his birthday. Table 34 presents the range of verbs used with the preposition at, including frequently used verbs and the specific number of verbs used by each child (lexical diversity). The small token counts for Jack, Mark and David make it difficult to comment on the extent to which the preposition has been generalized to usage with a range of verbs. Similarly, the modest token counts of Peter and Kevin means that it is not surprising that the preposition only appears with two verbs in their data. However, Table 34 reveals a marked difference between the use of at in the data of these children and the data of Brett, Liam and Joseph. Not only does the preposition occur with greater frequency, but it is clear that the preposition has been extended to use with a number of different verbs illustrated in the examples “did work with Peggy at school” (B1: 52), “and the barbie screamed at him” (L3: 712), and “she’s at day care” (Jo4: 1595).

124 Understanding space and time Table 34. Verb use with the preposition at lexical child diversity bare PP US Stuart 0 0 Rick 0 0 Brett 10 2.9 Jack 1 50 Mark 1 66.7 Aus. David 3 0 Peter 2 0 Liam 14 17.6 Kevin 2 33.3 Joseph 9 17.4

look 0 0 65.6 0 33.3 33.3 90.9 17.6 50 4.3

Verbs (%) see be 0 0 0 0 0 5.6 50 0 0 0 0 0 0 0 2.9 20.6 0 16.7 26 21.7

do 0 0 2.9 0 0 0 0 8.8 0 8.7

have 0 0 2.9 0 0 0 9.1 2.9 0 4.3

other 0 0 20.1 0 0 66.7 0 29.6 0 17.6

What is particularly striking about the data for the preposition at is its appearance with the verb look (as noted in chapter three) and the manner in which the phrase look at is used by the children. As discussed above, early uses of at in the language of typically developing children centre on this collocation, which has great pragmatic utility (Rice 2003; Tomasello 1987). However, since difficulties with joint attention behaviours such as declarative pointing and shared eye-gaze are often reported in children with autism (Loveland and Landry 1986; Mundy, Sigman, and Kasari 1990), use of the collocation look at to engage the attention of others would not be expected from the current children. As it happens, of the eight children whose data contain instances of at, six of them produce this expression at least once during the course of the sessions. The data of Peter, Liam and Kevin contain many instances in which the context makes clear they are imperative constructions being used to attract the attention of others in the room, either during the course of general activities, as in the example “hey, look at that one” (K2: 2196) or in pretend play as in “look at me, I’m dragon barbie” (L3: 743). For Peter, almost all instances of at in his data were the collocation look at. Joseph’s data only included a single example, but it was clearly an imperative construction. The situation is not so clear for Brett and David. David also produced a single example in the utterance “look at this mess here” (D2: 176), but his mother commented that this expression is one she uses quite frequently. Similar to Peter, over half of Brett’s productions of the preposition at are with the verb look. Close examination of the contexts, however, reveal that the majority of instances, while not overtly coded for subject, appear to express Brett’s own actions. Nonetheless, there are examples where the

Detailed examination of in, on, up, and at

125

mother’s response does support the interpretation of look at as a pragmatic device: (3)

Brett: Mother: Mother: Brett:

look at the gate. I see it. I see the gate. it's a farm. (B1: 747-750)

In the context of the well documented social difficulties of children with autism, the extent to which the collocation look at is utilized by the children is a surprising result. Table 35 sets out the range of subjects whose spatial interactions are encoded by the children. Table 35. Subject use with the preposition at 1 US

Aus.

child Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

Sg 0 0 57.2 0 33.4 66.7 18.2 29.4 0 34.8

Pl 0 0 0 0 33.3 0 0 5.9 0 13.1

Subject use (%) 2 3 Sg Pl Sg Pl 0 0 0 0 0 0 0 0 17.1 0 17.1 0 100 0 0 0 0 0 0 33.3 33.3 0 0 0 81.8 0 0 0 23.5 0 35.3 5.9 66.7 0 33.3 0 13.1 0 34.8 4.2

? 0 0 8.6 0 0 0 0 0 0 0

Despite the limited use of the preposition at by many children, the spatial locations of objects and people other than the speaker and the transferral of objects initiated by others are well represented in the data. Jack is the only exception, with both of his utterances containing second person subjects. Due to the high number of look at constructions, second person singular subjects feature strongly in the data of Peter and Kevin. Brett and David are the only children with a clear preference for encoding their own actions and locative states, illustrated in examples such as “I have to look at the gate” (B1: 924). Liam and Joseph demonstrate the most well developed extension of the preposition to subjects other than the speaker, illustrated in the examples

126 Understanding space and time “there was different seaweed at my beach, too” (L2: 1248) and “we went to see Santa at the shop again” (Jo3: 236). In summary, the data shows that the preposition at emerges according to the same pattern of development as documented for typically developing children. For those children whose data contained instances of at, the majority of examples encoded spatial relations and only children who had clearly acquired the term extended it to abstract and temporal uses. As with the other three prepositions considered in detail, the percentage of misuses was quite high. However, the nature of these misuses reveal evidence that category formation is in process for these children. The most notable parallel to typical development arising from the data was the underextension of the preposition at in the collocation look at by many children. 5. Overview: Developmental flowchart The somewhat sparse research into the acquisition of prepositions by children with autism presents a profile of limited and highly irregular use of this word class. Early investigations of general language features of individuals with autism found that prepositions were frequently omitted (Bartolucci et al. 1980; Kehrer 1977; Wing 1969) or used erroneously (Churchill 1972; Wing 1969). Similarly, Menyuk and Quill (1985) concluded that the highly polysemous nature of the word class and the complexity of the relations expressed make the acquisition of prepositions difficult for children with autism. However, recent studies of language development in children with autism have found that general lexical growth and conceptual development progress in similar fashion to typically developing children (Lord and Paul 1997; Tager-Flusberg 1986; Tager-Flusberg, Paul and Lord 2005) and McGee, Krantz, and McClannahan (1985) found evidence that children with autism could acquire productive use of prepositions. Although there was evidence of delayed acquisition, there was no indication in the current study that the manner in which prepositions are acquired by children with autism deviates from the path of acquisition documented for typical development. This parallels the profile of verb acquisition of the children presented in the previous chapter. The individual results for the acquisition of prepositions are represented collectively in a developmental flowchart. The boxes on the left denote the various stages of development evident in the data, in terms of the types of relations encoded and the order in which they appear. Due to the considerable variation in regard to the order in which they emerge, and the time period of

Overview: Developmental flowchart

127

this development in typically developing children, grammatical prepositions were not included.

Spatial: basic, e.g. in, on, up Abstract: conventional e.g. turn on

Stuart (US): 3;4 IQ 61 Rick (US): 4;7 IQ 94

Mark (US): 7;7 IQ 75 Temporal: metaphor, e.g. in Abstract: metaphor, e.g. into, about

Jack (US): 6;9 IQ 91 David (Aus.): 3;6 IQ 100

Spatial: proximity, e.g. beside

Brett (US): 5;8 IQ 108 Peter (Aus.): 4;6 IQ 76

Temporal: complex, e.g. before

Temporal: duration e.g. for Spatial: projective, e.g. behind

Kevin (Aus.): 6;7 IQ 84 Liam (Aus.): 5;6 IQ 75 Joseph (Aus.): 7;2 IQ 66

Figure 20. Developmental flowchart of preposition acquisition in children with autism

These stages proceed in accordance with typical development as discussed in section 3 of this chapter. That is, in the earliest stage, the basic spatial relations such as containment, support and directionality, as well as conventional abstract expressions centred on the operation of appliances emerge. This is followed by the next stage in which temporal uses of spatial prepositions are acquired, as well as the expression of abstract locations. In the third stage, the

128 Understanding space and time spatial concept of proximity, and more complex notions of temporality begin to be articulated, before the final stage begins. In this stage (which may last for some time) the temporal concept of duration begins to be expressed, as well as prepositions which encode projective relationships. The location of the children is an approximate indication of their level of semantic development, based on the data presented in section 3. There is a potential inconsistency in the data which may be problematic for the claim that children with autism acquire prepositions in the same order as typically developing children. The issue is that, despite his location on the flowchart, David’s data contains no instances of temporal prepositions extended from the basic spatial terms. This makes the presence of prepositions encoding abstract locations and the temporal conjunction after seem anomalous. However, all of the abstract locative instances relate to the operative states of appliances which are more akin to the early emerging turn on constructions, and their emergence before temporal prepositions is not without precedent in typical development (Rice 2003). As noted in section 3.2, the single instance of after in David’s data does not suggest he has acquired the concept. While there is no clear evidence of atypical development, the ranking of the children in regard to the stage reached in the acquisition of prepositions is an interesting feature of the data. That is, similar to the profile of development for verbs presented in chapter three, the ordering of the children is not consistent with either their age or their Performance IQ. Figure 20 shows that Mark from the US data set, while being the oldest child at seven years and seven months, is by no means the most advanced. Once again, Brett from the US data set demonstrates less sophisticated semantic development than a number of the other children, despite having the highest Performance IQ. As with the acquisition of verbs, language development (as measured by MLU) appears to account for the stage of acquisition reached by each child. Specifically, the ranking of the children for the acquisition of prepositions corresponds to their ranking regarding language development as determined by MLU. Given the close relationship between the acquisition of prepositions and grammatical development, this is not a surprising result. However, as discussed in chapter three, the argument that MLU is better considered a global measure of expressive language ability limits its status as an independent measure and does not provide a satisfactory explanation for the level of development reached by the children. I will revisit the question of what influences the rate of semantic development in the acquisition of prepositions in chapter six, where I will argue that the social cognitive skills of each child offer an alternative explanation.

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6. Conclusion The main results of this investigation into the semantic development of prepositions in the language of children with autism can be summarized as follows. I hypothesized that a semantic profile of the acquisition of prepositions in children with autism would be consistent with typical development for highly salient, concrete spatial relations but the encoding of more complex spatial relations as well as temporal and abstract relations would result in limited or erroneous preposition use. Analysis of the data revealed that the acquisition of prepositions proceeds in accordance with the order of emergence of category types observed in typical development. That is, concrete spatial relations are encoded before the more complex notions of proximity which are, in turn, developmentally prior to projective relationships. Similarly, temporal and abstract relations appear only after the emergence of spatial concepts. Contrary to expectation, some children demonstrated quite advanced development in the extent to which temporal and abstract terms were acquired, in the use of grammatical prepositions and, in the aspectual uses of the preposition up. An unanticipated result was the usage of the collocation look at by six of the ten children as a pragmatic device to initiate joint attention. Furthermore, the rate of misuses in the data was surprisingly small and examination of the nature of these misuses revealed parallels with typical development in the overextension of early acquired prepositions in less prototypical contexts.

Chapter 5 Verbs of thought, desire, and speech in grammatical development

1. Introduction The presence or absence of complex clauses in the language of children with autism and the form they take is of interest for a number of reasons. The verbs in question (desire, cognition and communication) have significance in the context of semantic development in autism, and they are also particularly relevant to current theories of language acquisition – both in typical development and in autism. Firstly, complex clauses often contain matrix verbs from semantic domains known to be problem areas for children with autism. As such, the extent to which they form part of the lexicons of these children is a pertinent consideration (Leslie and Frith 1988; Tager-Flusberg 1992; 1993). Secondly, complex clauses with mental state verbs and communication verbs offer the opportunity to examine the relationship argued to exist between theory of mind development and syntactic development (de Villiers 2000; 2005; de Villiers and de Villiers 1999; de Villiers and Pyers 1997; Tager-Flusberg 2000). And, finally, the data from these children can contribute to the ongoing debate regarding the nature of language acquisition in typical development: that is, whether children are born with innate principles and parameters that specify linguistic development (Crain 1991; Crain and Thornton 1998; Pinker 1984) or whether language acquisition, including grammatical development, occurs via the general cognitive processes of intention-reading and pattern-finding (Bates and Elman 1996; Diessel 2004; Tomasello 2003). The first issue I consider in this chapter is the level of semantic development evidenced in the complex clauses produced by the children. In the present study, I hypothesized that the nature of complex clauses present in the data would not indicate advanced semantic development within these targeted categories.

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2. Verbs of desire The syntactic structure of complex sentences containing verbs of desire offers the opportunity to examine the nature of grammatical and semantic development in children with autism. As noted in chapter three, investigations of spontaneous productions of young children reveal that they begin to talk about desires around their second birthday (Huttenlocher, Smiley, and Charney 1983; Bartsch and Wellman 1995). Complex constructions appear soon after and initially occur as a highly formulaic matrix clause such as “I wanna go” in which the verbal elements “want” and “to” are contracted, the subject of the matrix clause is usually a first person singular pronoun, and the verb is in the present tense (Diessel 2004). The vast majority of infinitival complements occur in the construction type NP-V-VP (e.g. “I want to eat the apple”) and only when the child is approximately two and a half years of age do constructions begin to appear in which the verb takes a noun phrase complement as well as the infinitival complement as in the example “I want you to eat the apple” (Bloom, Tackeff, and Lahey 1984; Diessel 2004). Negation of want infinitival constructions develops later. Examples such as “I don’t want to eat it” first appear in the spontaneous speech of typically developing children when they are approximately three years old (Bartsch and Wellman 1995; Diessel 2004). For children with autism, it is argued that the use of verbs of desire is restricted to talk about their own desires with only minimal references to the desires of others (Tager-Flusberg 1992; Ziatas, Durkin, and Pratt 2003). However, little is known about the syntactic development within this class of verbs. Table 36 presents the distribution of clause types in the data, including the percentage of complex clauses versus basic clauses and the various subtypes of complex clauses. As indicated in Table 36, almost all of the children produced complex clauses with verbs of desire. With the exception of Mark, all children produced examples of non-finite complements with the verbs want and need, such as examples (1) and (2): (1)

I want to make a star please (B1: 619)

(2)

I need to have a drink (D1: 1279)

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Table 36. Percentage distribution of clause types with verbs of desire Basic (%) child US

Aus.

Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

92.6 91.6 34 31.8 100 78.6 42.4 46.2 39.3 23.3

Complex (%) matrix + non-finite matrix+ finite (NP)-V-VP NP-V-NP-VP 3.7 4.2 59.5 68.2 0 21.4 42.4 37.2 57.1 63.4

0 0 6.5 0 0 0 15.2 3.8 0 0

0 0 0 0 0 0 0 7.7 0 10

other 3.7 4.2 0 0 0 0 0 5.1 3.6 3.3

Rick and Stuart each produce a single example, their data consisting almost entirely of simple sentences. The other sentences for these two children are a type of serial verb construction: “need go” (S4: 517); “want help open” (R2: 357). The remaining children from the US data set and the Australian children all produce more substantial numbers of complex clauses. In terms of the distribution of these clauses, Table 36 indicates that the majority of complex clauses are NP-V-VP constructions, such as examples (1) and (2) above. Only Brett from the US data set and Peter and Liam from the Australian data set, that is, three of the ten children, produce complex clauses with both a nominal complement and an infinitival complement (NP-V-NP-VP), as in the utterance “I want you to get the monster” (P4: 1271). For those children who do produce sentences with non-finite subordinate clauses, examination of the data reveals that the rules of co-referentiality which govern whether or not the subject is overt are always observed. That is, sentences such as “I need to find the cup” (Jo3: 1058) and “I don’t want it to break” (B3: 61) are consistently produced by all children. In terms of grammatical acquisition, this suggests a sensitivity to the rules which govern the formation of complex sentences with infinitival complements. As I discussed in chapter three, the range of subjects occurring with verbs of desire in the data separates the US children from the Australian children. While all of the US children use verbs of desire with only the self as subject in complex sentences, none of the Australian children’s productions are restricted to a formulaic “I want” combined with a complement. Rather, they use verbs of desire with a range of subjects, illustrated in the examples “we

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need to put this up and put some more play doh in” (P2: 359) and “Carol doesn’t want to have a…play a game” (K1: 370). Even the youngest Australian child produces similar complex sentences such as “[do you] wanna play play doh, susan?” (D4: 2366). The data of Liam and Joseph contains instances of finite subordinate clauses because their verb lexicons include verbs such as hope (e.g. “I hope the fish will protect them” [L1: 868]) and wish (e.g. “I wish I had a little dog” [Y1: 776]). The other clauses for Joseph occur as complements to the verbs think and say as in the utterance “I think my plant needs a drink” (Jo3: 1309). The other clause of Kevin’s data contains a verb of desire in the subordinate clause “when you want to” (K2: 18). Liam’s data has both relative clauses as in “all the stuff that I need” (L2: 1045) and the subordinate clause “that’s where he wants to put his ball” (L3: 579). Table 37 sets out the presence or absence of features associated with infinitival complements which appear later in development as children’s constructions become more complex. Studies of children’s conversational data reveal that locational expressions (NP-V-(NP)-VP-PP) usually appear in the language of typically developing children at approximately two and a half years of age while negation begins to appear around the third birthday (Diessel 2004). Other tenses and the presence of modifiers indicate that complex sentences with verbs of desire are not simply formulaic constructions, and verb phrase ellipsis suggests an awareness of phrase boundaries at a syntactic level, as well as the use of ellipsis to avoid redundant information in a conversational context. Table 37. Later emerging features of infinitival complements

US

Aus.

child Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

NP-V-(NP)VP-PP 8 8 9 9 8 9 9 9 9 9

Negation 8 8 9 8 8 9 9 9 9 9

Past Tense 8 8 8 8 8 8 8 9 9 8

Modifiers 8 8 8 8 8 8 8 9 9 9

VP ellipsis 8 8 9 8 8 9 9 9 9 9

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As indicated in the first column, the data from quite a number of children included constructions with prepositional phrases expressing location, such as “I want you to fix the fence inside there” (P4: 1552), as well as grammatical relations such as instrument, as in the utterance “I want to take pictures with my camera” (B1: 886). Similarly, negation, as in the example “don’t wanna turn [it]” (D4: 2362), is present in the data of just over half of the children. Only Liam and Kevin produce complex clauses where the matrix verb encodes tenses other than present tense, illustrated in the example “because he wanted to go up and rescue the cat” (K4: 1385). The inclusion of modifiers, as in the sentence “I just want to show you” (Jo2: 1887), only occurs in the data of Liam, Kevin and Joseph. An interesting feature of the data is that many of the children who produce verbs of desire in matrix clauses with non-finite complements also have examples of verb phrase ellipsis in their data as illustrated in the following exchange: (3)

Child: Child: Mother: Child: Mother:

ok, I write it. I write… no, don't write on there. I want to. I need… David, David, don't write on there. (D2: 514-519)

Examples such as these are particularly interesting, as they suggest that these children can connect with the utterances of their conversational partners to some extent, and understand the rules that govern the omission of redundant information in a conversational context. In summary, the data on complex clauses with verbs of desire reveal that although there is clear variation in the level of complexity in the constructions produced by each child, many of the children demonstrate quite advanced syntactic and semantic development. While the clause types for the majority of the US children are predominantly or exclusively basic, the data of Brett, Jack and the Australian children contains high percentages of complex clauses with verbs of desire. Only Brett, Peter and Liam produce examples with both nominal and infinitival complements, but other features of these complex sentences reveal that many of the children have knowledge of more than simply a formulaic “I want XP” structure: the Australian children encode subjects other than the speaker; Brett and the Australian children produce negated clauses; Liam and Kevin talk about past desires; and, various modifiers are present in the data of Liam, Kevin and Joseph, illustrated in the examples “I just want to show you” (Y2: 1887) and “I only need the start

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music to do it” (L4: 887). Other interesting features of the data are the adherence to the rules for the encoding of subjects of subordinate clauses and the presence of verb phrase ellipsis. 3. Verbs of cognition The presence or absence of mental state verbs in the language of children with autism provides opportunity to consider the syntactic and semantic development for the concept of cognition, as well as the issue of theory of mind development. Studies of conversational data indicated that typically developing children begin to use verbs of cognition just prior to their third birthday (Bartsch and Wellman 1995). These early instances are usually formulaic utterances such as “I don’t know”, but are not considered to be expressions of knowledge states. By the age of three, typically developing children’s use of mental state verbs are more clearly genuine references to epistemic states. These verbs also begin to appear in complex sentences, which are the focus of this chapter. For children with autism, many researchers have contended that the development of mental state terms is extremely limited and their appearance in the language of these children is rare (Leslie and Frith 1988; Tager-Flusberg 1992; 1993). However later studies have found no difference in the use of mental state terms by children with autism in comparison to typically developing children or children with intellectual disabilities matched on language ability (Capps, Kehres, and Sigman 1998; Tager-Flusberg 1995; Tager-Flusberg and Sullivan 1995). As noted above, mental state verbs with content clauses begin to appear in the natural language of typically developing children at approximately three years of age. De Villiers (2000) suggested that the majority of early instances of mental state verbs with complements function more as opinion markers. That is, these constructions consist of the verb think, used with the speaker as subject and are of the form “I think p”, where p is a proposition which is true (de Villiers 2000: 97). Similarly, Diessel (2004: 77; Diessel and Tomasello 2001) argued that children’s early use of complement clauses with cognitive verbs are not true examples of content clauses embedded in a matrix clause, but are formulaic uses in which the matrix clause functions more as a clausal operator of the complement clause, than a distinct proposition concerning the act of thinking or knowing. That is, the formulaic matrix clause primarily functions as an epistemic marker indicating degree of certainty, as well as functioning as an attention getter and a marker of illocutionary force. Interestingly, studies of adult conversational data have found a similar pattern

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for the use of “I think” constructions (Mullan 2006; Thompson and Mulac 1991). The emergence of complex sentences in which the embedded proposition is false indicates a shift towards the recognition of mental states as different from reality. Bartsch and Wellman (1995) found that, although they are rare, genuine references to beliefs or knowledge states occur shortly after the initial appearance of mental state verbs in complex clauses. The presence of these contrastive utterances in natural speech is of interest, since it is some months after this before children are able to recognize false beliefs in an experimental setting (de Villiers 2000). Table 38 sets out the distribution of complement clauses for the verb think. Specific features analysed include subject use and the tense of the matrix verb, as well as the presence of false propositions and verb phrase ellipsis. Table 38. Distribution of complements for the verb think Subject (%) 1 Sg other child US Stuart 0 0 Rick 0 0 Brett 0 0 Jack 0 0 Mark 0 0 Aus. David 100 0 Peter 100 0 Liam 80 20 Kevin 80 20 Joseph 100 0

Clause type (%) think p other 0 0 0 0 0 0 0 0 0 0 100 0 100 0 80 20 100 0 100 0

Tense (%) pres other ellipsis false p 8 8 0 0 8 8 0 0 8 8 0 0 8 8 0 0 8 8 0 0 8 8 100 0 9 8 100 0 8 9 66.7 33.3 8 8 100 0 8 8 100 0

Table 38 reveals that none of the US children produced any complex clauses with the verb think, in contrast to the Australian children whose data do contain examples. In terms of specific features, the verb think is used with only the speaker as subject, and only in the present tense for David, Peter and Joseph, illustrated in the examples “I think that goes here” (D2: 1490), “I think this one fits” (P3: 79) and “I think my plant needs a drink” (Jo3: 1309). Moreover, all of the complements contain propositions which are true. This suggests that the “I think p” construction may indeed function as an opinion marker for these children. Kevin’s complements with the verb think also encode true propositions with a present tense matrix verb. However, the production of a construction with someone other than himself as the subject – “think susan winner?” (K2: 1577) – indicates recognition of the knowledge

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state of another person. Interestingly, only Peter’s data contains examples of verb phrase ellipsis with complement clauses such as “I think it doesn’t” (P3: 71). Only Liam produces sentences which include both present and past tense matrix verbs and false propositions, as in the following exchange: (4)

Researcher: Child: Researcher: Child: Researcher: Child: Researcher: Researcher: Child: Child:

what is it? a swan, um… it does look like a swan, doesn't it? a chicken. I think it's a goose. a goose. cos there is a chicken there. can you see where the chicken is? I thought it was a swan. this is a swan. (c picks up another bird.) (L1: 1217-1227)

The other constructions under the clause type heading include a relative clause – “that’s me thinking in your head” (L3: 236) – an existential subordinate clause as complement – “I think there might be a fairy in here” (L3: 1633) – and an inverted wh-cleft – “that’s what I thought” (L4: 407). Further information regarding the extent to which these children use cognition verbs with complements to encode mental states can be found in the complex sentences with the verb know as matrix verb. The distribution of complements is set out in Table 39, including subject use, clause types (declarative (DEC), interrogative (INT) and other), the tense of the matrix verb and whether verb phrase ellipsis is present in the data. As Table 39 shows, none of the US children, nor Peter from the Australian data set produce complex clauses with the verb know. David and Kevin each produce a single utterance in which the self is subject, the content clause is interrogative and the matrix verb is present tense. However, “I know” appears to function less like an epistemic marker and more like a genuine expression of the participant’s knowledge state in these examples than similar examples with “I think”: “I know what go up in this” (D1: 639); “I know how to leave a bit” (K3: 2306). Liam and Joseph do produce complex sentences with subjects other than the speaker, illustrated in the examples “do you know how to shut it?” (Jo2: 203) and “so its know it’s his” (L1: 680) (where the first “it” refers to Liam’s younger brother). Table 39 reveals that only the subordinate clauses of Liam’s data include declaratives such as “I know it’s Odette” (L4: 571), as

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well as interrogatives. The “other” subordinate clauses for Liam and Joseph are a relative clause in the example “I know one that I can do” (L3: 114) and a non-finite complement in the question “do you want to know?” (Jo3: 149), respectively. Table 39 also shows that verb phrase ellipsis is only present in the data of Liam and Joseph. Table 39. Distribution of complement clauses for the verb know

US

Aus.

child

Subject (%) Clause type (%) 1 sg other DEC INT other

Stuart Rick Brett Jack Mark David Peter Liam Kevin Joseph

0 0 0 0 0 100 0 86.1 100 10

0 0 0 0 0 0 0 13.9 0 90

0 0 0 0 0 0 0 22.2 0 0

0 0 0 0 0 100 0 72.0 100 98

0 0 0 0 0 0 0 2.8 0 2

Tense (%) VP present past ellipsis 0 0 0 0 0 100 0 100 100 100

0 0 0 0 0 0 0 0 0 0

8 8 8 8 8 8 8 9 8 9

As with the data on complex clauses with verbs of desire, there is marked variation in the level of development for cognition verbs, ranging from the absence of complex clauses to the linguistic expression of false belief by Liam. Moreover, many children are less advanced in their acquisition of mental state terms as compared to the data on desire, even taking into account the fact that the verbs of desire emerge before mental state terms in typical development. However, as discussed in chapter three, it is clear that the language of some children indicates a recognition of mental states about which they can and do converse. The structure of the complement clauses with cognition verbs reveals that, at least in some examples, there appear to be genuine instances of embedded complements even for the youngest child of the Australian children at three and a half years of age. 4. Verbs of communication Verbs of communication are of interest in the context of the semantic development of children with autism for a number of reasons. The presence or absence of communication verbs provide information about the extent to

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which these children can actively engage in conversation or report on other conversations. Moreover, it has been argued that communication verbs provide the linguistic platform for the acquisition of verbs of cognition with complement clauses (De Villiers 1995; 2000). Studies of naturalistic data found that verbs of communication appear in the language of typically developing children towards the age of two (Dale and Fenson 1996; Tomasello 1995) and are used early to report on the speech of others as well as the child’s own comments. Complex clauses with communication verbs emerge at around the age of two-and-a-half. While Bartsch and Wellman (1995) found that these constructions appear before complements with verbs of cognition in three out of the four children in their study, Diessel (2004) found the reverse. In contrast to the pattern of development with mental state verbs in complex sentences, communication verbs often occur with modifiers, are often in the past tense and appear with a range of subjects (Diessel 2004), as illustrated in the following examples: (5)

a. b.

The kitty says he wants to come in. He said yes he will give you a cow. (Diessel and Tomasello 2001: 122)

As discussed in chapter three, the extent to which children with autism use communication verbs is debated in the literature. Tager-Flusberg (1995) found that the children with autism were equally competent in their use of direct quotation in the production of narratives as the control groups of typically developing children and children with intellectual disabilities. In contrast, Loveland et al. (1990) found considerable differences in the ability of individuals with autism to use verbs of communication for the expression of direct quotations in narrative story telling. Table 40 reveals the distribution of complement clauses with the verb of communication say.6 Features considered include subject use, the tense of the matrix verb, the presence of false propositions and the types of complements included in the data – declarative (DEC), jussive (JUSS) and interrogative (INT). The table indicates that only half of the children produced complex sentences with verbs of communication. Interestingly, the total number of clauses is less than the number of instances for mental state verbs for all children except Joseph.

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Table 40. Distribution of complement clauses for the verb say

child US Stuart Rick Brett Jack Mark Aus. David Peter Liam Kevin Joseph

Subject (%) 1 sg other 0 0 0 0 0 100 0 0 0 0 0 0 0 100 33.3 66.7 66.7 33.3 33.3 66.7

Complement (%) DEC JUSS INT 0 0 0 0 0 0 100 0 0 0 0 0 0 0 0 0 0 0 100 0 0 100 0 0 66.7 33.3 0 83.3 0 16.6

Tense (%) pres past false p ellipsis 8 8 0 0 8 8 0 0 8 8 100 0 8 8 0 0 8 8 0 0 8 8 0 0 8 8 0 100 8 8 0 100 8 8 0 100 8 8 33.3 66.7

Consistent with typical development, the majority of sentences produced by the children contain someone other than the speaker as subject, as in the single example from Brett’s data “they say don’t walk” (B4: 875). A further similarity with typically developing children is found in the high percentage of constructions where the matrix verb is past tense, such as “I said I wanna show you something” (L4: 2110). In terms of clause types, Table 40 reveals that the majority of complements are declaratives, illustrated in the example “the teacher said you have to leave it at school” (Jo3: 166). Only Kevin and Joseph produce utterances with other types of complements. Kevin’s data contains an imperative, or jussive content clause with the verb say in the utterance “my sister said shut up Higgy” (K3: 1549). Joseph produces a small number of interrogative complements with the verb say, such as “they said where’s Santa?” (Jo4: 674). While not represented in Table 40, Kevin is the only child whose data contains modifiers in the main clause, illustrated in the example “I just said they fight each others” (K3: 1678). Since it has been argued that complex clauses with communication verbs appear prior to complements with cognitive verbs in the language of typically developing children, the absence of certain features with the verb say in the data of all children is an interesting result. These absent features include verb phrase ellipsis and, in particular, false statements such as “you said you ate your peas” where the claim that the peas were eaten is in conflict with actual events. This is especially noteworthy in the case of Liam, whose data contains three instances of false propositions as complements for the verb think, including a single instance with someone else as the subject. The following exchange reveals he understands the concept of false statements, since he is

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clearly arguing that his mother says one thing, but does another. However, he does not express it in the syntactic framework of complementation as might be expected: (6)

Child:

Child: Child: Child: Child: Child: Mother: Child: Mother: Child: Child: Child: Mother: Mother: Child:

I tell mummy all the time when it's…when it's…when it's… (c proceeds to re-enact a conversation between his mother and himself). “what's tomo-…what I…what am I doing tomorrow, mum”. “I don't know, I don't think about it”. “what are we doing tomorrow?” “I'll tell you”. that's what you do, mum. okay, I don't tell you? yeah. yeah, I tell you what we're doing tomorrow. yeah, and you…and “I…and I don't know what I'm doing tomorrow”. “I might think tomorrow”. and you don't think, you…oh, yeah the only time… sometimes I say when I don't know what we're doing tomorrow I say “I have to think about it”. that's right. yeah. (L2: 1802-1819)

In general, there is a similar pattern to the other categories examined in regard to the variation of development with communication verbs and complementation. That is, while some children did not produce any examples of complex clauses with the verb say, others demonstrated more advanced knowledge in the range of subjects encoded and the types of complements embedded. For those children who produce complex clauses with verbs of communication, there is no clear pattern on whether complementation with communication verbs or mental state verbs is more advanced. The syntactic structure of complex clauses for Brett, Kevin and Joseph includes more advanced features for communication verbs, while David, Peter and Liam show better development with cognitive verbs. I will address the implications of these results later in this chapter.

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5. Summary A number of interesting observations can be made in regard to the development of complex clauses in the language of the children across the three semantic categories considered. Firstly, there is considerable variation between the children in terms of their ability to produce complex sentences with verbs of desire, cognition and communication. This is noticeably the case when the data from the American children is compared to the data from the Australian children. With the exception of Brett and Jack, the American children produced few or no complex clauses with verbs of desire as compared to the Australian children who demonstrated substantially more advanced syntactic and semantic development. Similarly, there was a noteworthy absence of complex clauses with verbs of cognition and (with the exception of Brett) verbs of communication for the American children, while the data of the Australian children contained quite advanced constructions. This variation in development can be explained in the context of the theory of mind development of each child. That is, all three verb categories examined in this chapter are either psychological state verbs, or are connected with a recognition of individual minds. As will be presented below, the better developed theory of mind abilities of the Australian children are reflected in their ability to converse on psychological states and communicative acts. The second observation is what the data reveals about the relationship between syntactic and conceptual development. That is, the complexity of the syntax produced by the children appears to be constrained by the semantic development within these three verb categories. For example, the American children Stuart, Rick and Mark have only a basic understanding of their own desires which restricts their syntactic expression of desires to either simple sentences or NP-V-VP constructions, and always with the self as subject. In contrast, the Australian children clearly have a more developed understanding of the psychological state of desire as well as mental states and the act of verbal communication, which finds expression in more advanced syntax. The most interesting data on this issue comes from the American children Brett and Jack. They demonstrate strong syntactic abilities in the expression of the concept desire, including constructions which are argued to appear only after complement constructions such as “I think X” and “she said X” are present in the language of typically developing children. I will further explore this issue in conjunction with theories of language acquisition in section 6.4.

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6. Theory of mind and complex clauses Verbs are central to the construction of sentences. This is true for both simple sentences and, in combination with other verbs, in complex sentences. The acquisition of verb meanings is inextricably linked, then, with grammatical development. This connection between syntactic and conceptual development extends to the purported relationship between social cognition and language development as presented in a number of recent accounts of language acquisition, which I examine in the remainder of the chapter. I formulated a series of hypotheses and research questions for the present study: in regard to the relationship between theory of mind development and the acquisition of complex clauses, I hypothesized that there would be no evidence of false belief understanding without expression in the syntax of complementation; on the issue of verbs of communication and theory of mind development, I hypothesized that the syntax of complex clauses would be more advanced with verbs of communication than with verbs of cognition; finally, concerning the nature of grammatical development, I considered whether the pattern of development in complex clauses would be indicative of usage-based approaches to language acquisition. I consider the theory of mind development of each child first. 6.1. Theory of mind development In order to investigate the relationship between theory of mind development and the acquisition of complex clauses, the extent to which the children demonstrate an understanding that other people have thoughts and beliefs which influence their actions must be determined. Under a broad definition of theory of mind, the emergence of theory of mind abilities occur in a series of developmental stages of which recognition of false belief is a specific phase (Hughes and Leekam 2004; Leekam 2007). The first manifestation of a theory of mind appears as joint attention and declarative pointing when the typically developing child is approximately eighteen months old (Baron-Cohen 1989; 1995). At this stage, young children are able to read communicative intentions and recognize shared attention on the same object between themselves and an adult, as well as engage an adult’s focus on an item by pointing to it (Bates 1976). In the next stage of development, children demonstrate an understanding of desires which begins at approximately two years of age (Bartsch and Wellman 1995; Huttenlocher, Smiley, and Charney 1983). This is followed by the appearance of pretend play in which children engage in

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activities such as pretending a banana is a telephone (Leslie 1987) or pretending to act out activities such as pouring drinks (Dunn and Dale 1984). The next stage in the development of a theory of mind is the comprehension and expression of simple emotions and an understanding of the relationship between desires and emotions, such as “people are happy when they get what they want” (L. Bloom 1998; Klann-Delius and Kauschke 1996). This stage occurs when typically developing children are approximately three years of age. By the age of three-and-a-half, typically developing children recognize that someone will act according to their beliefs (Bartsch and Wellman 1995) and they recognize that seeing leads to knowing (Woolley and Wellman 1993). However, it is usually not until the age of four that typically developing children can differentiate their own mental states from those of others and thus recognize false belief (Wellman 1990; Wimmer and Perner 1983). At this stage, children also begin to understand the connection between mental states and emotions (Lagattuta, Wellman and Flavell 1997). The impairment of theory of mind in children with autism is an issue which has received much attention in the literature (Baron-Cohen, Tager-Flusberg, and Cohen 1993; 2000). The difficulties in understanding false belief experienced by the majority of individuals with autism is well-documented. However, few studies have considered theory of mind in autism in the context of the developmental path presented above. Steele, Joseph, and TagerFlusberg (2003) found significant improvement in theory of mind abilities in a twelve-month period, using a battery of tasks designed to reflect the developmental stages in the acquisition of a theory of mind. Other studies indicate that children with autism often show limited joint attention skills and only infrequently engage in pretend play (Baron-Cohen 1995). While understanding of the concepts of desire (Baron-Cohen, Leslie, and Frith 1986) and simple emotions (Ozonoff, Pennington, and Rogers 1990; Tager-Flusberg 1992) are not impaired in children with autism, mental state terms are not a feature of their language (Tager-Flusberg 1992; 1993) and the majority of children cannot solve false belief tasks or second-order false belief tasks (Baron-Cohen, Leslie, and Frith 1985; Perner, Leekam, and Wimmer 1987). The theory of mind development for each child in the present study is represented in the following developmental flowchart.7 The approximation of stages reached by the children was determined by examination of the transcripts and the video footage (Australian children only) as well as consideration of their verb use.

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Joint attention: recognition of communicative intent, shared attention & proto-declarative pointing. (begins at 18th mths. in typical development)

Understanding desire: recognition that desires motivate people’s actions. (begins at 2 yrs. in typical development)

Pretend play: distinguishing between the world of pretence and the real world in games and activities.

Stuart (US): 3;4 IQ 61

Rick (US): 4;7 IQ 94

Understanding of simple emotions: comprehension and/or production of simple emotion terms. (begins at 3 yrs. in typical development)

Mark (US): 7;7 IQ 75 Brett (US): 5;8 IQ 108 Jack (US): 6;9 IQ 91

Recognition of Beliefs: recognition that people act according to their beliefs and seeing leads to knowing. (begins at 3 ½ yrs. in typical development)

David (Aus.): 3;6 IQ 100

Understanding of False Beliefs: recognition that people may have thoughts and beliefs different from reality. (begins 4 yrs. in typical development)

Peter (Aus.): 4;6 IQ 76

Kevin (Aus.): 6;7 IQ 84 Joseph (Aus.): 7;2 IQ 66 Liam (Aus.): 5;6 IQ 75

Figure 21. Developmental flowchart of theory of mind abilities

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As with lexical development addressed in chapters three and four, Figure 21 indicates there is wide variation in the theory of mind abilities of the children. All of the children show some ability with joint attention and understanding the concept of desire. However, Stuart, Rick, Jack and Mark do not attempt to engage the attention of those around them and only sometimes respond to their mothers’ invitations to look at items. The remaining children display varying difficulties with joint attention as well, but they also actively seek out the interest of those around them in the use of the collocation “look at”, as discussed in chapter four. In regard to an understanding of desire, only the Australian children recognize the desires of others while the US children restrict their talk to expression of their own desires. With the exception of Stuart, all children engage in pretend play. However, there is considerable variation in the extent to which this occurs and in the elaborateness of the games. Rick, Brett, and Mark play games such as pretending to cook with toy utensils and pretending to pour drinks with toy tea sets. Jack, David and Kevin demonstrate more advanced play in the animation of a toy, such as a Snoopy or a baby doll. Peter and Joseph engage in similar pretence, but they hold imaginary conversations either between themselves and a fictional character, in the case of Joseph, or between two anthropomorphized creatures such as two vehicles or two animals, in the case of Peter. Liam exhibits the most elaborate pretend play in his spontaneous construction and narration of a drama involving Barbies and a toy dragon. Comprehension of and, in some cases, production of simple emotion terms was evident for Brett, Jack, Mark and the Australian children. Only the Australian children revealed a recognition of beliefs, such as the understanding that seeing leads to knowing. For example, David’s disagreement with his mother over whether or not he had heard his baby sister stir via the baby monitor culminated in the utterance “I go see [if] Melanie awake” (D4: 2075). The most surprising find in the data was the extent to which a number of the Australian children engaged with the concept of false belief. While the data is open to interpretation, it appears that Kevin and Joseph have some understanding of false belief. This is illustrated in the following scenario involving Kevin who is playing a board game with his mother and the researcher. He has rolled the dice, but wants to roll a higher number, and so spontaneously concocts this story to distract his mother: (7)

Child: Mother:

mummy, there's a spider on your back. oh no. (mother plays along and pretends to check, child rolls the dice again)

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one again. oh no, you'll have to do it again. mum, look at the really little spider. (mother looks, child laughs and rolls the dice again) (K1: 1434-1442)

For Liam, the situation is much clearer. As noted above, his data includes the expression of false complements such as “I thought it was pollypockets on here” (L: 725) (pollypockets are a type of small doll) which he uttered as he was looking at the box of a Wendy doll. Given the young age of these children (Liam 5;6, Kevin 6;7, Joseph 7;2), their emerging comprehension of false belief is an entirely unexpected result. 6.2. Syntactic complements and theory of mind development The acquisition of verbs as a lexical category is clearly pertinent to the issue of theory of mind development, as talk about thoughts and beliefs is typically expressed using mental state verbs. However, the fact that use of cognition verbs such as think, know and believe often involves complex syntax also highlights an issue regarding the interplay between linguistic and cognitive development. There is a substantial body of research to support the premise that theory of mind skills play a significant role in lexical development (e.g. Rollins 1999; Tomasello and Farrar 1986) but in regard to theory of mind development and complex clauses, there is debate on whether mastery of false belief reasoning is contingent on the acquisition of complex syntactic structures (de Villiers 2000; 2005; de Villiers and de Villiers 1999; de Villiers and Pyers 1997) or whether language only enables expression of theory of mind abilities (Chandler, Fritz, and Hala 1989; Gopnik and Wellman 1994; Perner 2000). De Villiers and colleagues (de Villiers 2000; 2005; de Villiers and de Villiers 1999; de Villiers and Pyers 1997) contend that the acquisition of complex clauses with verbs of cognition is a prerequisite skill for the ability to reason about false beliefs. Conversely, children who do not develop the syntax of complementation will not fully comprehend the concept of false belief. De Villiers and Pyers (1997; 2002) conducted a longitudinal study on a group of typically developing children who were an average age of three years and four months at the beginning of the study. Over a period of twelve months, the children were tested on four occasions on three standard false belief tasks and

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a series of language comprehension and elicited production tasks which targeted knowledge of complex syntax with verbs of cognition and communication. De Villiers and Pyers also included measures of syntactic productivity on samples of spontaneous speech using the Index of Productive Syntax (Scarborough 1990). The overall results supported the hypothesis that children’s knowledge of the syntax of complementation in both comprehension and production would predict their ability to reason about false belief. De Villiers and de Villiers (1999) conducted a similar series of experiments with orally-taught deaf children and found that competency with complex syntax also predicted skills on false belief reasoning for this population group. However, other research did not support the findings of these studies. Cheung et al. (2004) investigated the relationship between the development of theory of mind and syntactic complements in both English- and Cantonesespeaking children aged four. As well as a series of standard false belief tasks and assessments of complement knowledge, they included tests of nonverbal intelligence and general language. In contrast to de Villiers and colleagues, Cheung et al. did not find that knowledge of syntactic complements uniquely predicted false belief reasoning skills, but that general language comprehension was an important factor. Miller (2001) conducted a study with children with Specific Language Impairment (SLI) who had an average age of four years and eleven months. She found that children with SLI performed as well as age-matched typically developing children on measures of false belief understanding when the linguistic demands of the tasks were low, but only performed as well as the typically developing group matched on receptive language when more linguistically complex false belief tasks were used. In a later study, Miller (2004) specifically addressed the relationship between false belief reasoning and syntactic complements in children with SLI. As well as a series of false belief tasks with varying linguistic complexity, the study included a sentence complement comprehension task. The results indicate that understanding of sentence complement structures only predicted performance on false belief tasks after chronological age was controlled, offering only partial support for de Villier’s claim. That is, while the ability to reason about false beliefs is not dependent on knowledge of sentence complements in children with SLI, this syntactic knowledge does enhance performance across a range of false belief tasks. Children with autism raise a somewhat different issue. That is, while oral deaf children and children with SLI do not exhibit problems in other areas of theory of mind, the theory of mind impairment in autism affects more than simply reasoning about false belief. However, as the acquisition of syntax in

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children with autism is argued to proceed in accordance with typical development (Bartolucci, Pierce, and Streiner 1980; Lord and Paul 1997; Tager-Flusberg 1988; 1994), and all of the Australian children from the present study produced complement clauses with either mental state or communication verbs, it is worth investigating whether the data reveals anything about the relationship between the syntax of complementation and false belief reasoning in children with autism. In regard to this issue, I hypothesized that there would be no evidence of false belief understanding without expression in the syntax of complementation. The results from the present study are mixed. As discussed in section 3, Liam is the only child to produce false complements with mental state verbs, which he does on three occasions. These false complements indicate an awareness of his own false beliefs and the following exchange indicates he is also aware that other people can have false beliefs. Liam describes deceiving his brother so that he could keep for himself a toy belonging to both of them: (8)

Mother: Child: Researcher: Child: Child: Researcher: Child: Researcher: Child: Child: Child: Researcher: Child:

that's supposed to be a sharing toy. oh, I hide it away from him. oh. I did and he +/ Eddie can't find it anymore. (irrelevant dialogue omitted) I pretended, I ju- I ju-, I put it away, I put it in the rubbish bin. did you tell Eddie that? yeah, that's why – oh. no, I didn't tell Eddie. I didn't tell Eddie. I hide it away in my, in here. (child gestures to under his t-shirt). yeah? and I runned in to my room and put it in my cupboard. (L2: 604-615)

While the direction of the relationship cannot be determined from a language sample, Liam’s production of false complements and his recognition of the false beliefs of others is consistent with de Villier’s theory. However, the data from Kevin and Joseph do not appear to support the claim that development of

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the syntax of complementation leads to an understanding of false belief. These children do not produce false complements, and yet there is evidence to suggest they do understand that people can have thoughts different from reality. Joseph describes playing the game hide and seek with his brother and mother, generally recognized as evidence that children understand false belief (Peskin and Ardino 2003). Similarly, Kevin tries to trick his mother into believing she has a spider on her back, as presented earlier in this chapter. While the data from Liam is consistent with the idea that children will only fully comprehend false belief when they have come to recognize that nonfactive verbs can take false propositions as complements, the data from Kevin and Joseph is not consistent with this idea. However, it must be noted that naturalistic data is limited in the extent to which it can address the origin of false belief reasoning. 6.3. Verbs of communication and theory of mind development A further issue regarding the process by which children develop an understanding of false belief is the purported role of communication verbs in the acquisition of complex sentences. De Villiers (1995 cited in 2005; 2000; 2005) suggested that complementation with mental state verbs is learned by analogy with parallel constructions containing communication verbs. Similar to think, the communication verb say can also have a false proposition as an embedded complement and the overt act of making statements (either true or false) is easier to process than the covert act of thinking. Consequently, children first acquire complex structures with verbs of communication before the same structures are extended to mental state verbs. There is support for this theory from studies of spontaneous speech and experimental studies. Bartsch and Wellman (1995) found that acquisition of communication verbs was developmentally prior to mental state verbs in the conversational data of three of the four children they studied. In an experimental setting, studies revealed that training children to understand false complements with verbs of communication can improve their performance on standard false belief tasks (Hale and Tager-Flusberg 2003; Lohmann and Tomasello 2003). However, Lohmann and Tomasello (2003) also found that children’s performance improved when the training condition targeted perspective-shifting discourse about deceptive objects. Ruffman et al. (2003) failed to find a correlation between theory of mind and complex syntax, concluding that general language ability and not syntactic knowledge enables false belief understanding.

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Tager-Flusberg (1997; 2000) has argued that individuals with autism are more reliant on the syntax for verbs of communication as an entry into the understanding of false belief. Twenty children and adolescents with autism participated in a study which included two false belief tests and a series of tests assessing knowledge of complex syntax with verbs of communication and cognition. Based on the data from these tests, Tager-Flusberg (2000) concluded that children with autism also use knowledge of sentential complements as a platform for false belief reasoning. However, unlike typically developing children, for children with autism the developmental link between the ability to pass standard false belief tasks and linguistic knowledge of syntactic complements is found with verbs of communication, rather than verbs of cognition. Tager-Flusberg and Joseph (2005) conducted a study using the experimental design of de Villiers and Pyers (1997) in which a battery of tests consisting of false belief tests and assessment of the comprehension and production of sentential complements was administered over two sessions, twelve months apart. Similar to the study reported in Tager-Flusberg (2000), Tager-Flusberg and Joseph (2005) found that general language abilities (as measured with IPSyn) and knowledge of sentential complements significantly predicted theory of mind skills as tested in false belief tasks for children with autism. Once again, the data indicated that acquisition of the syntax of complementation with communication verbs, in particular the embedding of false complements, is the critical enabler of theory of mind abilities in children with autism. For the present study, I hypothesized that the syntax of complex clauses would be more advanced with verbs of communication than with verbs of cognition. The data from the present study does suggest that complex sentences with communication verbs are more advanced in the language of the children on some semantic and syntactic features. While subject use was almost exclusively first person singular with cognition verbs, there was a greater range of subjects encoded with communication verbs. Similarly, there was greater variation in the tense of the matrix verb for communication verbs, with mental state verbs appearing almost entirely in the present tense. There was no clear differentiation between the categories on the different subordinate clauses embedded and very minimal use of modifiers with both think and say. However, other syntactic features such as verb phrase ellipsis and, more particularly, false propositions did not occur with communication verbs. This is of interest since Liam’s data contains three examples of false propositions with the mental state verb think and, as discussed earlier, there is at least one instance in which Liam talks about false statements, but not within the syntactic framework of complementation.

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There is also variation between the children on whether complex clauses with communication or cognition verbs appear more frequently in the data. Brett and Joseph’s profiles are consistent with the idea that complementation with communication verbs enables the acquisition of like structures for cognitive verbs. Brett produces no complex clauses with mental state verbs, but his data includes a single example of the verb say with a complement. Similarly, Joseph’s data contains many more complex sentences with communication verbs than with verbs of cognition. In contrast, David’s data contains no examples of complex clauses with communication verbs, despite the presence of complex sentences with both think and know verbs. Likewise, Peter produces only two complement constructions with the verb say as in the example “I will do it, said the hippopotamus” (P4: 1331), but thirty-six with the mental state verb think. As with verbs of cognition, there is no clear pattern either supporting or refuting the premise that it is via complementation with verbs of communication that children acquire the ability to embed false propositions with verbs of cognition. While some syntactic features were more advanced with communication verbs, others were more developed with mental state verbs. However, the scope of naturalistic data is somewhat limiting for a comprehensive investigation of this issue, and previous research has not identified spontaneous use of sentence complements as a useful predictor of false belief reasoning (Miller 2004). 6.4. Complex sentences and theories of language acquisition Any study of the acquisition of verbs inevitably encounters the question of how grammatical development proceeds in child language acquisition. As L. Bloom (1978, quoted in Golinkoff et al. 1995) noted, verbs represent the intersection of semantic and syntactic development and, as such, provide information about the means by which children come to know the grammatical structure of language. In order to use verbs productively, children must know information about the number and nature of participants licensed by individual verbs, as well as inflectional morphology encoding person, number and tense. At the level of the verb phrase, children must also learn the expression of tense, aspect and modality via inflection and the use of auxiliary verbs. The role of theory of mind in language acquisition is also central to the question of the origin of grammar. Recent theories of language acquisition claim that not only is theory of mind a necessary skill for lexical acquisition, but that the ability to infer the intentions of others is critical for the development of

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grammar. As a population group for whom problems in social cognition are a diagnostic feature, the process of language acquisition in children with autism offers a unique perspective on this debate. There are two main approaches to grammatical development in typically developing children. One account views linguistic development as the product of a general capacity for learning, without the requirement of domain specific skills unique to the task of language acquisition. Researchers from usagebased perspectives have argued that grammatical development emerges on the basis of input from the language environment which is processed via general cognitive, social-cognitive and learning skills (Bates and Goodman 1999; Slobin 1973; Tomasello 2003; Van Valin 1986). More particularly, children do not possess an innate language faculty, but the process of language learning is dependent on experience and occurs over many years (Tomasello 2003). Under a social-cognitive approach, there are two cognitive skills which are critical for language acquisition. The first of these skills is summarized under the broader heading of intention-reading, or theory of mind as it is also known. Tomasello (2003) argued that joint attention skills and the ability to interpret the communicative intentions of others are necessary for the acquisition of all elements of language, from lexical development to complex syntactic structures. Moreover, theory of mind abilities are central to the enterprise of linguistic communication, since language is primarily about manipulation of other people’s mental states. The second necessary skill is pattern finding, which encompasses a range of abilities including categorization, schema building, statistical learning and analogical reasoning (Gentner and Markman 1997; MacWhinney 1982; Rakison and Oakes 2003; Saffran, Aslin, and Newport 1996; Schneider 1999; Tomasello 2003). These pattern finding skills are argued to be essential for grammatical development since children take a conservative approach to language learning. That is, early utterances are organized around a set of specific constructions upon which they build as their linguistic knowledge increases. One version of this item based approach is the Verb Island Hypothesis, which stipulates that young children’s command of syntax is restricted to verb-centred constructions containing open positions for nominal items (Tomasello 1992). Furthermore, the grammatical structures of language which children acquire are usage-based inasmuch as they have evolved through the cultural and historical processes of grammaticalization and syntactization (Bybee, Perkins, and Pagliuca 1994; Tomasello 2003). In this view, language is not generated from underlying principles, but consists of a well ordered accretion of linguistic constructions.

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One of the first systematic studies of verb acquisition from the sociocognitive perspective was Tomasello’s (1992) diary study of his daughter’s verb use between the ages of fifteen and twenty-four months of age. He found that T’s verb use was limited to a small number of construction types and syntactic development proceeded in a piecemeal fashion. Longer sentences were built up from individual verb constructions, but these more complex constructions were not generalized to new verbs which followed the same simple to complex pattern of development. Similar results have been found in other studies of early verb use in the language of typically developing children (Lieven, Pine, and Baldwin 1997; Pine, Lieven, and Rowland 1998). For researchers within usage-based approaches, experimental investigations of children’s ability to acquire novel verbs revealed that between the ages of eighteen months and three years, children are extremely conservative in their production of new verbs, using them only in the same types of constructions to which they were exposed during the course of the studies (Akhtar and Tomasello 1997; Dodson and Tomasello 1998; Olguin and Tomasello 1993; Tomasello et al. 1997). Children are similarly conservative in comprehension tests which require them to interpret transitive constructions containing novel verbs previously presented as intransitive, with the majority of children under three performing at chance level (Akhtar and Tomasello 1997). Further studies have made direct comparisons between typically developing children’s ability to use verbs transitively when presented with a novel verb in a transitive, passive, intransitive or imperative construction (Brooks and Tomasello 1999; Lewis and Tomasello in preparation, cited in Tomasello 2000; Tomasello and Brooks 1998). All three studies consistently found that only children who heard the novel verb in the transitive condition could use the verb in a transitive construction. When the novel verb was presented only in passive constructions (Brooks and Tomasello 1999), intransitive constructions (Tomasello and Brooks 1998), and imperative constructions (Lewis and Tomasello in preparation) very few children could produce transitive utterances in response to questions of the kind “what’s he doing?” or “what’s happening?”. The results of the observational and experimental studies led researchers from the usage-based approach to conclude that there is no evidence in the language of young children to support the claim that knowledge of syntactic structures and parameters is innate. Rather, the language abilities of these children point to the conclusion that language acquisition is an experientialist enterprise. The other main perspective on the nature of grammatical development comes from the nativist tradition. In this view, children are born with an innate Universal Grammar which consists of a set of fundamental linguistic

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principles occurring in all natural languages, and parameters which demarcate the variations which can occur among natural languages (Chomsky 1965; 1975; 1986; Crain 1991; Pinker 1990). In contrast with usage-based theories, it is argued that the language apparatus humans possess is modular and does not overlap with other cognitive processes (Crain and Thornton 1998; Fodor 1983; Pinker 1994b). Within theories of Universal Grammar, children are also equipped with a Language Acquisition Device (LAD) for the singular purpose of hypothesising a series of grammars on the basis of input from the language environment until the target grammar is achieved (Chomsky 1965; 1981; Crain 1991; Crain and Thornton 1998). These grammars hypothesized by the LAD are also constrained by the principles and parameters of Universal Grammar. The key difference between the LAD of Universal Grammar and the statistical learning account of the usage-based approaches is that the LAD is both specific to language and constrained by the Continuity Hypothesis. The Continuity Hypothesis stipulates that the grammars hypothesized by the LAD can only differ from adult grammar to the extent that grammars of natural languages differ from each other (Crain 1991; Crain and Thornton 1998; Pinker 1984). Researchers from nativist approaches to language acquisition have argued that the principles and parameters which govern the process of language acquisition must be innate on the basis of a number of considerations. Firstly, as well as learning which syntactic structures are permissible in their target language, children must also learn which are not. Secondly, since the language input, by default, consists only of structures and meanings which are sanctioned by Universal Grammar, information regarding what it is not permitted must come from another source. Studies investigating whether or not negative evidence is provided by parents or caregivers led to the conclusion that the necessary information is not available to children in this form (Brown and Hanlon 1970; Demetras, Post, and Snow 1986; Hirsh-Pasek, Treiman, and Schneiderman 1984). Consequently, it is argued that negative linguistic principles, or constraints, are also part of the innate language faculty to ensure children do not generate too large a grammar, or are able to recover from overgenerations (Pinker 1990). This argument is referred to as the Poverty of the Stimulus (Chomsky 1981; 1988; Crain and Thornton 1998). Researchers from the nativist tradition conducted experiments which aimed to show that very young children possess knowledge of core linguistic principles to which they adhere, in contrast to expectations under socialcognitive approaches. On the issue of whether or not children possess knowledge of structure-dependence transformations, Crain and Nakayama (1987) examined two- and three-year-olds production of yes/no questions.

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They found that the children were sensitive to constituent structure in the formation of both simple and complex yes/no questions and did not use nonsyntactic strategies in the production of questions such as “Is the boy who can see Mickey Mouse happy?”. Further evidence of children’s knowledge of syntactic structure is claimed from studies demonstrating that French children determine the order of the negative particle pas and the verb on the basis of whether or not the verb is finite (Deprez and Pierce 1993), and that a German child demonstrated clear understanding that the placement of the verb in a clause is dependent on whether or not it is finite (non-final) or non-finite (final) (Poeppel and Wexler 1993). Moreover, elicitation studies have found that children are knowledgeable about subtle grammatical information such as when contraction may occur in English (Crain and Thornton 1991; Thornton 1990; 1996). Thornton (1990; 1996) found that children aged four years adhere to the constraint determining when the verbal elements want and to may be contracted, allowing sentences such as “who do you wanna kiss?” but blocking sentences such as “*who do you wanna kiss Bill?”. Directly contrasting with the view that children do not produce utterances not accounted for on the basis of language input, Thornton (1990) demonstrated that rarely observed long-distance wh-questions such as “what do you think is in the box?” could be elicited from children as young as two-and-a-half years of age. Lee (2004) investigated the language production of two young children acquiring Cantonese from the ages of around eighteen months until just after two-and-a-half years. Detailed analysis of the early word combinations of these children indicated that the data consisted of predominantly productive patterns, rather than item based schemas. Naigles, Hoff, and Vear 2009 found a similar pattern of acquisition in their study of eight young children’s early verb use. These results are in contrast to the account of early syntactic development proposed by Lieven and colleagues (Lieven, Pine, and Barnes 1992; Lieven, Pine, and Baldwin 1997) in which children’s early word combinations are frozen units which they subsequently analyse for the purpose of syntactic acquisition. The results of these studies are taken as evidence to support the claim that children possess innate knowledge of the principles and parameters which govern the structure of natural languages that cannot be learned via language input. The linguistic abilities of individuals with autism provide an interesting window into the debate regarding the origin of grammar. As discussed extensively in chapter two, social impairments are a core feature of the disorder, meaning studies of the process of language acquisition in children with autism can contribute to the understanding of the role played by social

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cognition in language development. Early accounts of grammatical development in autism described syntactic and morphological development as atypical (Kanner 1946) and the reliance of children on echolalic utterances for communicative purposes was considered indicative of an atypical process of grammatical development (Prizant 1983; Simon 1975). However, other studies found evidence that the grammatical knowledge of children with autism does not differ from either typically developing children or children with intellectual disabilities (Bartak, Rutter, and Cox 1975; Bartolucci, Pierce, and Streiner 1980; Bartolucci et al. 1976; Howlin 1984; Pierce and Bartolucci 1977). Tager-Flusberg et al. (1990) conducted a longitudinal study of the language acquisition process for six high functioning children with autism. Transcripts of spontaneous speech samples were analysed for grammatical development by charting mean length of utterance (MLU), and the order of emergence of grammatical constructions was assessed using the Index of Productive Syntax (IPSyn) (Scarborough 1990). Tager-Flusberg et al. (1990) found that the MLUs of each child followed the developmental patterns observed in typical development and were consistent with the MLU development of the six children with intellectual disabilities which formed the control group. Similarly, both the children with autism and the children with intellectual disabilities profiled in accordance with typical development on the IPSyn, with the emergence of grammatical features occurring in the same order and rate of frequency as documented for typically developing children. TagerFlusberg et al. (1990) concluded that the language difficulties of children with autism do not include an underlying impairment in grammatical ability. Furthermore, Tager-Flusberg (1988; 1994) argued that the evidence from language acquisition in children with autism does not support social-pragmatic theories of grammatical development, but is indicative of the autonomy of syntax from other aspects of communicative development. In contrast to the Tager-Flusberg et al. (1990) study, a more recent examination of the relationship between pragmatic skills and grammatical development in children with autism which used the same data sample yielded conflicting results. Rollins and Snow (1998) also used the IPSyn scores as reported in Tager-Flusberg et al. (1990) as a measure of syntactic abilities, but they also calculated rates of change for each child using a Hierarchical Linear Modelling technique. Social-pragmatic skills were assessed using the Inventory of Communicative Acts – Abridged (INCA-A) (Ninio et al. 1994) for the categories of: negotiation of immediate activity, social participation and joint attention – all of which were language-based. Rollins and Snow (1998) found that those children who demonstrated good joint attention skills

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also showed significant growth in syntax. Conversely, those children with consistently poor joint attention skills during the time period language samples were collected did not show significant growth in syntax. In contrast to TagerFlusberg (1994), Rollins and Snow (1998) concluded that there is a strong relationship between grammatical development and pragmatic skills, both in typical development and in autism, which they argued offers support for social-pragmatic theories of language acquisition. However, they also conceded that their study could not determine the direction of this relationship. Kjelgaard and Tager-Flusberg’s (2001) large scale study on the language abilities of children with autism revealed significant heterogeneity within the sample of eighty-nine children in regard to language skills. Using a battery of standardized language tests, they found that the language abilities of some children were equivalent to their typically developing peers, some of the children performed substantially below age expectations, while other children profiled like children with Specific Language Impairment, displaying deficits in grammatical ability and tests of non-word repetition (Tager-Flusberg and Cooper 1999). Thus, there does not appear to be a single profile of linguistic abilities for autism. While grammatical development proceeds according to typical development for some children with autism, others demonstrate atypical development which parallels the strengths and weaknesses of children with SLI. There is conflicting evidence regarding the nature of grammatical development in autism, as compared with the profile of typical development. A large number of studies revealed that the children with autism who participated showed no indication that syntactic development proceeds in an atypical manner, in spite of the social impairment which is central to the disorder. In addition, research has established that there are a small percentage of children with autism who do not exhibit any delay in the course of language development. These studies offer support for the theories of Universal Grammar in which the language apparatus is both modular and innate. However, later research offers some support to the social-pragmatic accounts. The finding that there is a significant relationship between joint attention skills and the rate of growth in grammatical development in children with autism accords with the central tenet of usage-based theories that linguistic knowledge is acquired via the general cognitive processes of intention reading and pattern finding. For the present study, I considered whether the pattern of development in complex clauses would be indicative of usage-based approaches to language acquisition. The data from the Australian children is not inconsistent with the premise that language acquisition is a by-product of social interaction, as their more

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advanced syntactic development could be attributed to their stronger sociocognitive skills reflected in their theory of mind development. Similarly, the exclusive use of the cognition verb think with first person singular subjects by David, Peter and Joseph and the predominance of constructions in the present tense with true propositions embedded in the data of all the Australian children is consistent with usage-based accounts. To recapitulate; early production of complex syntax is organized around formulaic matrix clauses, before this framework is expanded to include features such as subjects other than the speaker, tenses beyond simply present and adverbial modifiers in the verb phrase (Diessel 2004; Diessel and Tomasello 2001). However, as noted in section 3, Mullan (2006) found that the predominant use of “I think” in conversational data of adult speakers of Australian English was also as an opinion marker which is consistent with previous studies of adult conversational data (Thompson and Mulac 1991). Therefore, it could also be argued that use of “I think” constructions in children’s conversational data simply mirrors adult use, and may not be indicative of an item-based approach to grammatical development. This argument is supported by Bartsch and Wellman’s findings that, although rare, genuine examples of embedded complements in the form of false propositions are present in the language of typically developing children shortly after the first appearance of complex clauses with the verb think. Moreover, the Australian children in the present study have problems with joint attention while simultaneously demonstrating a sensitivity to grammatical rules such as coreferentiality and verb phrase ellipsis. The syntactic development of the US children Brett and Jack is more problematic for usage-based theories. As noted in section 5, the problems in social cognition of these two children is manifest in their problems with joint attention and the lack of linguistic evidence to suggest they recognize that the actions of other people are motivated by their desires, emotions and beliefs. Consequently, a theory which explains language acquisition, including grammatical development, in terms of children’s ability to engage with and process linguistic input predicts that these two children should demonstrate limited ability with the syntax of complex clauses. While this is true for complement clauses with mental state verbs, the data on infinitival clauses appears to be in conflict with this prediction: despite their problems with social cognition, Brett and Jack reach a level of development in the syntax of complementation with verbs of desire which is not easily explained by usagebased theories of language acquisition. There were no examples of complementation for mental state verbs; however, Brett and Jack produced syntactically advanced sentences with verbs of desire such as “I need to go to

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the closet” (J4: 201) and “I don’t want mum to sing” (B1: 1021) which are argued to appear after complex sentences with the verb think in typical development because of their syntactic and morphological complexity (Diessel 2004). If a child’s ability to acquire language is dependent on his or her capacity for social cognition, the uneven profile of syntactic development evident in the data of these children would not be an expected result. In contrast, the expression of concepts for which Brett and Jack have at least a limited understanding reveal a knowledge of syntax more easily explained on the basis of a set of innate linguistic principles and a specific language acquisition device (LAD) which are not dependent on non-linguistic skills such as joint attention. 7. Conclusion Across all three semantic categories there is considerable variation between the children in the extent to which complex clauses have been acquired. While the data of some children reveals quite limited semantic and syntactic development, others demonstrate advanced skills in their expression of desires, mental states and communication. On the issue of false belief reasoning and complementation with cognition verbs, the results are mixed. Liam’s production of false complements with the verb think and his understanding of false belief in other domains is concordant with the claim that the acquisition of false complements with non-factive verbs enables full comprehension of false belief. However, the apparent understanding of false belief by Kevin and Joseph in the absence of any contrastive utterances in the data is not. Similarly, there was no clear pattern in regard to whether the development of syntax in complex clauses with verbs of communication was more advanced than with verbs of cognition. The final issue considered was the nature of complex clauses in the language of children with autism and their contribution to the debate on theories of language acquisition. Examination of the data revealed that the pattern of development of complex clauses in the data was not consistent with the predictions of usage-based approaches to language acquisition.

Chapter 6 Issues and implications

1.

Overview of study

The primary purpose of the present study was to investigate semantic development in the acquisition of verbs and, as a related issue, the acquisition of prepositions. The development of verbs in the language of children with autism is a relatively unexplored domain, and the focus of the study was to investigate whether the process of acquisition accords with typical development. It was hypothesized that the acquisition of verbs would proceed as documented for typically developing children where semantic categories overlap with concepts centred on sensorimotor development, but profile as disjointed for categories whose semantic properties are concerned with social knowledge and awareness of the internal states of others. The analysis of verb use indicated that the order of emergence of category types is concordant with typical development, and examination of misuses revealed no evidence to indicate atypical development, despite the process of category acquisition being slowed. That is, the types of misuses identified in the data were comparable to those identified in the language of typically developing children. Consistent with the hypothesis, categories denoting sensorimotor perception and simple internal states, such as verbs of activity, change of state and desire, were well represented in the verb lexicons of all children. In contrast, the results did not support a profile of disjointed, or uneven, development. That is, the following categories were better developed in the lexicons of some children than expected on the basis of previous studies: categories concerned with psychological states (e.g. verbs of emotion and cognition) and other concepts which require greater abstraction, such as communication, causative and the general category of abstract verbs. A similar profile of semantic development was revealed in the data on preposition use. That is, the acquisition of prepositions proceeds in accordance with the order of emergence of category types observed in typical development. Once again, there was little evidence to support the claim of many researchers that preposition development is atypical in the language of children with autism. While the hypothesis predicted that a semantic profile of the acquisition of prepositions in children with autism

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would be consistent with typical development for highly salient, concrete spatial relations but the encoding of more complex spatial relations as well as temporal and abstract relations would result in limited or erroneous preposition use, examination of the data revealed that this was not the case. Consistent with preposition development in typical development, there was evidence in the data of all children that concrete spatial relations were encoded before the more semantically complex notions of proximity, followed by projective relationships. Similarly, temporal and abstract relations (where they were present) never occurred in the absence of spatial relations. Moreover, quite advanced uses of temporal and abstract prepositions were present in the data of some children, as well as grammatical prepositions and aspectual uses of the preposition up. As with verb use, the rate of misuses in the data was both unexpectedly small and paralleled the semantic overextensions observed in typical development, offering further support to the conclusion that there was no evidence indicative of atypical development. I examined semantic development as evinced in the production of complex sentences in the context of a number of theories addressing the process of language acquisition. On the issue of semantic development per se, I hypothesized that the nature of complex clauses present in the data would not indicate advanced semantic development within the targeted categories of desire, cognition and communication. While the data of some children was consistent with the hypothesis, other children demonstrated quite advanced development in the expression of desires, mental states and communication. In regard to the relationship between theory of mind development and the acquisition of complex clauses, I hypothesized that there would be no evidence of false belief understanding without expression in the syntax of complementation. Only the Australian children produced complement clauses, and the results were mixed. While the data of David, Peter and Liam were consistent with the hypothesis, the apparent understanding of false belief of Kevin and Joseph in the absence of false complements was not. Further to the issue of theory of mind and complex clauses, I hypothesized that the syntax of complex clauses would be more advanced with verbs of communication than with verbs of cognition. Once again, the results were mixed. The profiles of some children offered support to the theory that complementation with verbs of communication develops prior to complementation with verbs of cognition. However, other children demonstrated more advanced development with verbs of cognition – including the production of false propositions. The final issue considered in

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the present study was the development of complex clauses in the language of the children in the context of theories of language acquisition. I considered whether the pattern of development in complex clauses would be indicative of usage-based approaches to language acquisition. I concluded that the pattern of development observed in the data was not consistent with the predictions of usage-based approaches to language acquisition. 2.

Semantic development

For semantic development in the acquisition of verbs and, as a related issue, the acquisition of prepositions, the primary question I asked was whether or not there was evidence of atypical development. As noted above, the results do not support the theory of atypical acquisition as posited by Menyuk and Quill (1985). Furthermore, the results on verb use did not fully support a profile in which psychological state terms are infrequent or markedly absent (Hobson 1986; Hobson and Lee 1989; Leslie and Frith 1988; TagerFlusberg 1992). Rather, the results are more closely aligned with studies in which children with autism demonstrated abilities in the production of mental state terms comparable to that of the control groups of typically developing children and children with intellectual disability (Capps, Kehres, and Sigman 1998; Tager-Flusberg 1995; Tager-Flusberg and Sullivan 1995). The Australian children, in particular, presented a greater capacity to articulate concepts centred on desires, emotions and beliefs – both their own and those of others – than predicted by previous accounts of the language abilities of children with autism. This is evident in the general production of verbs and the expression of conceptually and syntactically complex sentences. A further reinforcement to the claim that lexical acquisition proceeds in accordance with typical development in children with autism, is the presence of lexical innovations in the data of some of the Australian children. This is a result not previously encountered in the literature. While lexical innovations in the form of neologisms or odd phrases have been observed in the language of children with autism as early as Kanner’s original case studies (Kanner 1943; Volden and Lord 1991), the coining of new verbs from nouns, and the overextension of the causative meaning encoded in many English verbs to noncausative verbs which was observed in the data of some of the Australian children signifies an awareness of covert semantic patterns not predicted by previous accounts of lexical

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development in children with autism (Menyuk and Quill 1985; Paul 1987; Rutter 1970). This lexical creativity indicates that not only do children with autism acquire verb categories along the same developmental path as typically developing children, but it is also possible for them to acquire covert semantic principles such as the causative element of transitive verbs in English leading to overextensions and innovations as documented in typical development (Bowerman 1982; Clark 2003). For the semantic development of prepositions, the extent to which many of the children had acquired terms within this lexical category was a surprising result. Although studies specifically examining the acquisition of prepositions in the language of children with autism are scarce, previous research has revealed that children with autism often demonstrate limited ability in the use of prepositions. That is, prepositions are often omitted, or used erroneously in the language of children and adolescents with autism (Bartolucci , Pierce and Streiner 1980; Kehrer 1977; Wing 1969). Churchill (1972) found that a child with autism was unable to generalize directional prepositions to novel situations, despite successful learning in an educational setting. Similarly, in their account of problematic areas of semantic development for children with autism, Menyuk and Quill (1985: 136) argued that since prepositions encode relations between objects and events, and are highly polysemous, they are an extremely difficult lexical class for children with autism to acquire. McGee, Krantz, and McClannahan (1985) found increased preposition use in free-play sessions after classroom interventions; however, the overwhelming majority of studies present findings that indicate only limited acquisition of prepositions in the language of individuals with autism. As discussed in chapter three, research focussed on the acquisition of verbs suggests that children with autism display limited knowledge of abstract categories in which meaning is not grounded in sensorimotor experience, and the general language use of individuals with autism is frequently described as pedantic, with somewhat extreme concrete precision (Ghaziuddin, Tsai, and Ghaziuddin 1992; Lord and Paul 1997; Mayes et al. 1993). Therefore, it was expected that preposition use in the data of the children of the current study would be both highly restricted, and include many misuses. As presented in chapter four, there was considerable variation between the children regarding the extent to which prepositions featured in the data, however, the results indicated that the acquisition of prepositions proceeds in accordance with the order of emergence of category types observed in typical development. Moreover, the number of misuses identified was remarkably low for the majority of the children, with only Mark from the

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US data set and David from the Australian children demonstrating difficulties encoding spatial relations, as discussed in chapter four. What is particularly interesting about the data is the lexical diversity within the vocabularies of many of the children. While the number of different spatial prepositions within their lexicons was quite low for the US children Stuart, Rick and Mark (seven or less), this is consistent with their level of language development, as measured by MLU (Stuart: 1.17, Rick: 1.73, Mark: 1.46). For the remaining children, the number of different spatial prepositions was surprisingly high, with six of the eight producing between twenty and twenty-seven different spatial terms, including the complex relations of proximity, and (for two children) projection. Further evidence of advanced semantic development is found in the use of less conventionalized abstract prepositions in the language of Peter, Liam, Kevin and Joseph (Australian data set). Closer investigation of the context of preposition use for those children with larger vocabularies of spatial terms revealed convincing evidence that the prepositions had been generalized, and were not restricted to a set of fixed expressions, as might be anticipated on the basis of the literature. While general purpose verbs such as put, go, and be feature strongly in the data, there was diversity in terms of the relations between objects and events encoded, and prepositions were extended to use with other verbs. Therefore, unlike the child with autism in Churchill’s (1972) study, the preposition use of the children of the present study indicates that it is possible for children with autism to acquire spatial prepositions (as well as temporal and abstract) at a level of semantic development which does not accord with the linguistic profile of autism in which language use is predominantly concrete and restricted. The advanced level of development in the present study is also reflected in the extent to which many of the children had acquired grammatical prepositions. Not surprisingly, there were very few instances of grammatical prepositions in the data of the US children Stuart, Rick and Mark. Table 23 of chapter four indicates that Jack (US) and David (Australian) used prepositions to encode five different grammatical relations; however, their actual token counts were quite modest. In contrast, the data of the remaining five children includes a broader range of grammatical prepositions, which have been generalized to their lexicons, encoding complex relations such as purpose (“that’s for screwing things” (P1: 160)) and dative (“Shannon gave this to me” (B3: 46)). Moreover, the data of Liam and Joseph (Australian) contain examples of later emerging grammatical prepositions in the use of genitive of (“that was the end of

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Christmas” (L4: 534)) and, for Joseph, full passive constructions (“he got caught by a man” (Jo1: 49)). The sophisticated preposition use of these five children is noteworthy, since grammatical prepositions encode highly abstract relations between people and objects. Once again, these results are not consistent with the language profile typically associated with autism, but reflect a level of development not anticipated on the basis of previous research. While there was no evidence of atypical development, the considerable variation between the children in terms of their semantic development needs to be addressed. In particular, is there an explanation for this variation that can be identified? As discussed in chapters three through to five, it was not the case that the older children displayed more advanced use of verbs and prepositions than the younger children. Specifically, there was no parallel between the progression of chronological age and semantic development. However, given the heterogenous nature of the autistic disorder, this is not a surprising outcome. Only a small proportion of individuals with autism have productive speech (Lord and Paul 1997), and within that sub-group there is a large amount of variation in terms of language ability (Kjelgaard and Tager-Flusberg 2001). Similarly, Performance IQ was not a good indicator of semantic ability in the use of verbs and prepositions. Those children with a high non-verbal IQ did not necessarily demonstrate more advanced development. Nonetheless, this is not an unexpected result, since one of the features of autism is a unique cognitive profile. Typically developing children display an even level of performance across the range of verbal and non-verbal tasks of standard IQ tests, whether they be high or low results. In contrast, children with autism tend to perform more strongly on non-verbal tasks and less strongly on tasks which assess verbal ability (DeMyer et al. 1973). Moreover, this result is consistent with the findings of Kjelgaard and Tager-Flusberg’s (2001) investigation of the language abilities of a large, heterogeneous sample of children and adolescents with autism. In this study, the subgroup of children with autism who scored in the normal range on a battery of standardized language tests included children whose IQ scores fell into the below normal range. As I discussed in chapters three and four, language development (as measured by MLU) appears to offer a better explanation for the ranking of children in terms of the stages of verb and preposition acquisition reached. For verb acquisition, children with an MLU of less than two are in the early stages of development as represented in the developmental flowchart in section 4.2 of chapter three; children with an MLU between three and four

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demonstrate further progression; and children with an MLU above four demonstrate the most advanced semantic development in their production of verbs. There is an even stronger parallel in the development of prepositions. The ranking of the children for the acquisition of prepositions as represented in Figure 20 in chapter four directly corresponds to their ranking for language development as determined by MLU. However, as discussed in chapter three, the role of MLU as an indicator of semantic development is problematic inasmuch as the relationship between MLU and expressive vocabulary skills renders MLU more of a global measure of expressive language ability (Dethorne 2002; Dethorne, Johnson, and Loeb 2005; Miller 1991). In the context of the present study, then, MLU does not provide an independent measure which can account for the variation in lexical acquisition between the children. An alternative explanation for the rate of semantic development in the acquisition of verbs and prepositions for each child is the role of social cognition, or theory of mind abilities. The ranking of children in terms of their theory of mind development as presented in Figure 21 of chapter five profiles very closely with the ranking of children in regard to their lexical acquisition presented in chapters three and four, and in their verb diversity figures as represented in Figure 16 of chapter three. That is, Stuart shows the least developed social cognition as well as the least advanced semantic development, followed by Rick and then Mark, all US children. Similarly, those children who demonstrate the most advanced theory of mind skills also have the most advanced semantic development in the target categories of verbs and prepositions: the Australian children Peter and Kevin, consistently rank seventh and eighth of the ten children on lexical development and theory of mind development, while Liam is the most advanced in verbs and theory of mind, and only marginally behind Joseph on prepositions, both of whom are also from the Australian data set. There is more variation in the order of Brett and Jack from the US data set and David from the Australian data set. While Jack demonstrates more advanced development than David and Brett in the acquisition of verbs, it is Brett whose development of prepositions is superior to that of David and Jack. In terms of theory of mind abilities, David has reached the stage of recognising beliefs, while Jack is slightly more advanced than Brett in the understanding of simple emotions. However, there are only marginal differences between these three children in their rates of development across the lexical categories, and they are consistently middle-ranked in the distribution of the children’s overall rankings. Consequently, the extent to which the children have advanced in the acquisition of verbs and

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prepositions could be attributed to their capacity for social cognition as evident in their theory of mind development. An interesting pattern in terms of the ranking of children is that the Australian children are consistently the most advanced, while the US children are consistently among the least advanced. Theory of mind development can account for the differences between the US and Australian children as well as the rankings in regard to semantic development. However, an explanation for the variation in theory of mind abilities between the children is impossible to ascertain in the context of this study. The role of social cognition in semantic development is well supported by previous studies of the language of typically developing children, as well as children with autism. Investigations into lexical acquisition in typical development have revealed that early vocabulary development is associated with the theory of mind skill of joint attention (Rollins 1999; Tomasello and Farrar 1986). Typically developing children can acquire object labels on the basis of an adult’s intention towards an object (Tomasello and Barton 1994), even when that object remains unseen during the experimental phase (Akhtar and Tomasello 1996) or the experimental design demands a sophisticated reading of the adult’s communicative intentions (Akhtar, Carpenter, and Tomasello 1996). The ability to infer the intentions of others is especially important for the acquisition of lexical categories where ostension does not play a role, such as verbs. Many verbs are uttered in the form of requests for action, in anticipation of an impending action or after the action has been completed but very rarely during the course of the action (Tomasello and Kruger 1992). Investigations into the process of verb learning have found that young children are very sensitive to pragmatic cues, such as adult behaviours and emotions, in the process of learning novel verbs. Tomasello and Barton (1994) tested the ability of twenty-four-month-old children to acquire novel verbs on the basis of pragmatic cues under two experimental conditions. In the first condition, an adult performed a novel action preceded by the comment “I’m going to plunk Big Bird!” which was followed by an accidental action to which the adult responded with “whoops”. Children participating in the second condition observed the “accidental” action first. When children in both conditions were asked to perform the action, they did so based on the adult’s intentional action. Further studies revealed that children can still acquire this knowledge if they do not see the intended action performed (Akhtar and Tomasello 1996). Even sixteen-month-old and eighteen-month-old infants are more likely to imitate an adult’s intentional action as opposed to an accidental

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one (Carpenter, Akhtar and Tomasello 1998) whether or not they see the action completed (Meltzoff 1995). Sabbagh and Baldwin (2001) argued that theory of mind abilities affect word learning beyond the early skills of joint attention. They found that three- and four-year-old typically developing children showed better word learning when the source of a novel word was a knowledgeable speaker. Furthermore, the more highly developed understanding of knowledge states typically associated with four-year-olds was reflected in the better performance of this age group in learning novel words from knowledgeable speakers who, nonetheless, expressed hesitancy. For children with autism, researchers have argued that a relationship exists between theory of mind development and language skills. Previous studies indicate that preschool-aged children with autism who demonstrate strong joint attention skills such as gesture and eye gaze develop more receptive language at an earlier age than children with deficits in nonverbal communication (Charman et al. 2003; Lord and Schopler 1989; Mundy, Sigman, and Kasari 1994). In an earlier study, Mundy, Sigman, and Kasari (1990) found that joint attention and play skills in young children with autism also predicted their language development as assessed twelve months later. These results have been supported by other studies where dyadic orienting and joint attention were found to be linked with language development in children with autism (Leekam, Hunnisett, and Moore 1998; Leekam, López, and Moore 2000; Leekam and Ramsden 2006). Similarly, Sigman and Ungerer (1981) found that the ability to engage in pretend play, such as interaction with dolls modelled on interaction with people, was highly related to receptive language levels in children with autism who had a mental age of approximately two years. The importance of the ability to understand speaker intention in the context of language development has been examined in individuals with autism. Paul and Cohen (1985) concluded that in the absence of explicit cues, individuals with autism experience difficulty in processing the communicative intention behind requests such as “can you colour this circle blue?”. Studies have also investigated the role of theory of mind manifest in joint attention skills in the vocabulary development of children with autism. Baron-Cohen, Baldwin, and Crowson (1997) assessed whether children with autism who had a language comprehension age of approximately two years used the gaze direction of a speaker uttering a novel word to infer the speaker’s intended referent. They concluded that the children with autism in their study did not often use the speaker’s direction of eye gaze as a strategy to infer speaker intention, leading to a high rate of failure in the

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acquisition of the novel word. Rollins (1999) undertook a longitudinal study to examine the relationship between vocabulary development and pragmatic skills in five children with autism. She, too, found that joint attention skills influenced the rate of vocabulary growth in the prelinguistic to early one-word stage of language acquisition. Sigman and Ruskin (1999) also undertook a longitudinal study on social competence in a sample of children with autism in which they discovered that the children who engaged in more joint attention behaviours achieved greater verbal skills over the course of the study. In the context of the present study, the direction of the apparent relationship between theory of mind skills and semantic development cannot be ascertained on the basis of the observational data. Nonetheless, it is clear that the results are consistent with the large body of work, in both typical development and language acquisition in children with autism, in which theory of mind skills are argued to play a significant role in lexical development. Another explanation for the pattern of results which is argued to be related to theory of mind development is the role of mirror neurons in the development of social cognition and, by extension, language development. Mirror neurons are a particular class of brain cells originally identified in the brains of monkeys (Di Pellegrino et al. 1992; Gallese et al. 1996; Rizzolatti et al. 1996). Early studies discovered that mirror neurons fire not only when a monkey performs a goal-directed action such as grasping an object, but also when a monkey observes another individual performing the same action. Further research found that mirror neurons also fire if a monkey hears a noise uniquely associated with an action (Kohler et al. 2002), or produces a mental representation of an action (Umiltà et al. 2001). Neurophysiological studies showed that a comparable mirror neuron system must exist in the human brain. Similar to the monkeys, mirror neurons fire when humans observe an action performed by another individual, as well as when the action is performed by the person (Altschuler et al. 2000; Cochin et al. 1998; Cochin et al. 1999; Hari et al. 1998; Fadiga et al. 1995). Moreover, while mirror neurons in monkeys fire simply on the basis of a simple action, the situation is more complex in humans: Iacoboni et al. (2005) found that the act of grasping a cup presented in different contexts (e.g. to serve tea versus clearing the table) produced differing activation of mirror neurons in humans. Further important distinctions between the mirror neuron systems of monkeys and humans are that, for humans, mirror neurons are argued to be of significance for higher-level cognitive processes such as imitation,

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language, theory of mind, and the understanding of emotions (Carr et al. 2003; Gallese and Goldman 1998; Iacoboni et al. 1999; Rizzolatti, and Arbib 1998). Notably, these are all areas of cognitive impairment in individuals with autism. Research in autism has revealed that the mirror neuron system in individuals with autism is dysfunctional. Analysis of the mu wave component of an electroencephalogram (EEG), which is related to the firing of mirror neurons, revealed that for individuals with autism, mirror neurons fire during actions performed by the individual such as opening and closing the hand, as for typically developing individuals. However, observation of the same action performed by another person does not result in the firing of the mirror neurons in individuals with autism as it does in typically developing individuals (Oberman et al. 2005). A similar profile of results was obtained in a study investigating mirror neuron activity in tasks designed to target responses to facial emotional expressions. That is, while the imitation and observation of emotional expressions triggered mirror neuron activity in the control group of typically developing children, the mirror neuron activity in the children with autism was significantly less (Dapretto et al. 2005). Moreover, the investigators found correlations between the level of mirror neuron activity in the children with autism and their scores on the social subscales of the Autism Diagnostic Observation Schedule – Generic (ADOS-G) and the Autism Diagnostic Observation Interview – Revised (ADI-R). That is, the higher the level of mirror neuron activity, the higher the individual child’s level of social abilities. As I noted above, mirror neurons have been associated with the development of imitation, language, theory of mind, and the understanding of emotions. Along with interpreting action events, these cognitive skills are directly relevant to the acquisition of verbs, which suggests that mirror neurons are also involved in the process of verb learning. In support of this view, researchers have found that mirror neurons are activated when typically developing individuals listen to sentences describing actions (Hauk, Johnsrude, and Pulvermüller 2004; Pulvermüller, Hummel, and Härle 2001; Tettamanti et al. 2005). In terms of language development in autism, the research on mirror neurons accords with expectations in the literature regarding verb acquisition in children with autism. That is, verbs whose meaning is centred on perceptible attributes such as physical movement are easier to acquire than verbs encoding intentional actions and abstract categories, particularly those related to psychological states. Oberman et al. (2005) showed that mirror neurons do not fire in typically developing children when the action observed does not involve human

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participation (e.g. two balls bouncing). Therefore, as Menyuk and Quill (1985) predict, simple verbs of activity should feature in the vocabularies of children with autism because the ability to acquire such concepts should not be affected by mirror neuron dysfunction. The results of the present study are only partly consistent with the claim that a dysfunctional mirror neuron system offers a unifying explanation for the social deficits observed in autism, manifest in language impairment. The semantic profiles of verb use of the US children Stuart, Rick, Mark and, to a lesser extent, Brett are consistent with the prediction that verbs grounded in sensorimotor experience will feature more strongly in the vocabularies of children with autism than verbs encoding intentional action and psychological states. However, these children did extend their use of activity and change of state verbs to encode actions initiated by people other than themselves with greater frequency than might be expected on the basis of the mirror neuron research. Furthermore, the extent to which many of the Australian children demonstrated knowledge of semantically advanced concepts centred on emotions and cognition does not accord with the mirror neuron dysfunction account of autism. While Dapretto et al. (2005) found that there was variation in the level of mirror neuron activity within the autism group, this level was still significantly below the mirror neuron activity of the typically developing control group. The ability of some children with autism to acquire these highly abstract concepts is an issue which has not been addressed in the area of mirror neuron dysfunction in autism. In terms of a theoretical explanation for the variation in semantic development observed in the present study, the theory of mind account is more consistent with the data than that offered by the mirror neuron dysfunction approach to autism. The connection between theory of mind and lexical development is better substantiated, and allows for the type of variation in abilities between children with autism which is currently problematic for the more uniform explanation of a faulty mirror neuron system. 3.

The effect of autism on the interrelatedness of verbs and prepositions

The results of the present study indicate that the acquisition of both verbs and prepositions in the language of children with autism each proceed in accordance with typical development. While there was evidence of delay,

on the interrelatedness of verbs and prepositions

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there was no evidence to suggest that the order of emergence of subcategories within these lexical domains deviates from the path of acquisition posited for typically developing children. However, it is apparent that factors such as general language delay and, in particular, delay in theory of mind development (see Figure 21 of chapter five) do have an effect on the rate and extent of semantic development within each category. Considering the close relationship between verbs and prepositions (Blake 1994), an interesting question arising from the present study is whether variation occurs in the rate of acquisition between these categories. That is, do language delay and theory of mind impairments affect development in one lexical category more than the other, despite this interrelationship? As I discussed earlier in this chapter, examination of the developmental flowcharts for acquisition of both verbs and prepositions presented in chapters three (Figure 15) and four (Figure 20) reveals that there is minimal variation between the children in terms of their verb use as compared with their preposition use. Stuart was the least advanced in the acquisition of both verbs and prepositions, followed by Rick and then Mark, all US children. Brett and Jack from the US data set and David from the Australian data set clustered together in terms of development across both lexical categories: Brett was more advanced in preposition use than Jack and David, while Jack’s verb use was more highly developed, semantically, than David’s and Brett’s. The Australian children Peter and Kevin consistently ranked seventh and eighth in the semantic development of verbs and prepositions. Of the remaining two Australian children, Liam was the most advanced in the acquisition of verbs and Joseph was marginally more advanced than Liam in the acquisition of prepositions. Moreover, while there is clear evidence of language delay in many of the children, the level of semantic development reached by each child is consistent across both lexical categories in terms of an approximate age equivalence in typical development, as represented in Figure 22. As illustrated in Figure 22, Stuart and Rick have reached the level of a typically developing child approximately two years of age in their use of verbs and prepositions, while Mark’s verb and preposition use is comparable to a typically developing child a little over two years of age. Brett, Jack and David demonstrate semantic knowledge in their use of verbs and prepositions which approximates that of an almost three-year-old typically developing child, while Peter’s semantic development in terms of production in both categories is in the region of a typically developing three-year-old. Finally, Kevin’s use of verbs and prepositions is roughly

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equivalent to a typically developing four-year-old, while Liam and Joseph reveal semantic development in their use of both lexical categories approximating that of typically developing children approaching the age of five.

Approximation of lexical development: Verbs and prepositions

Age level in typical developmen

6 5 Liam

4

Joseph Kevin

3 Brett Jack

2 1

Stuart

Rick

David

Peter

Mark

0 Prepositions

Verbs

Figure 22. Semantic development in verbs and prepositions

In support of the interrelatedness of verbs and prepositions, those children whose semantic development had progressed to a sound understanding of the intentionality of people’s actions were the children whose preposition lexicons were more likely to include a larger number of grammatical prepositions. Thus, rather than simply describing the perceptual attributes of events and activities in constructions such as “ride a horse” (R3: 727) and “play with yarn” (M4: 1551) which featured strongly in the data of the US children Stuart, Rick and Mark, the remaining children used prepositions in similar constructions to encode relations such as beneficiary “mummy I do it for you” (D1: 1082), reason “I went over for a sleep over” (L1: 488), and purpose “they for magic” (Jo4: 1504). Similarly, the same

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children also had examples of dative constructions such as “maybe you can give that game to me” (K4: 2017) in their data. The recognition by these children that actions are motivated by intentions is manifest in the use of these types of grammatical prepositions in combination with more semantically complex verbs. The results from the present study suggest that the cognitive and linguistic impairments which form part of the autistic disorder do not affect the interdependency of verbs and prepositions in the acquisition process. Similar to the profile of development for verbs and prepositions as separate lexical categories, the data suggest that delay in language acquisition and theory of mind development do influence the acquisition process, but do not lead to atypical development such as an uneven rate of acquisition between verbs and prepositions. 4.

Theory of mind and complementation

A further issue I examined in the present study is the relationship of theory of mind to other aspects of language acquisition: in particular, the syntax of complementation and the understanding of false belief. De Villiers and colleagues (de Villiers 2000; de Villiers and de Villiers 1999; de Villiers and Pyers 1997) have argued that only when children have mastered the syntax of complementation – specifically the recognition that non-factive verbs such as think can have propositions which are either true or false – can they reason about false belief. Furthermore, de Villiers (2000) contends that verbs of communication (which can also be non-factive) facilitate the acquisition of complement structures through recognition of false statements in the overt act of speech. However, other studies have yielded results conflicting with de Villiers work in typical development and in oral deaf children. Cheung et al. (2004) found that general language abilities and not the syntax of complements was a more important factor in the development of theory of mind abilities for English- and Cantonesespeaking children aged four. In a study with four-year-old children with SLI, Miller (2001) concluded that age was a better indicator of theory of mind abilities than language development. Whitehouse and Hird (2004) proposed that children with autism who pass theory of mind tests are those who can conceptualize the false belief situation, irrespective of their syntactic ability. The well-documented difficulties with theory of mind associated with the autistic disorder mean that children with autism offer an interesting

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perspective on this issue. This is especially relevant in light of the fact that the acquisition of syntax in children with autism proceeds in accordance with typical development (Bartak, Rutter, and Cox 1975; Pierce and Bartolucci 1977; Tager-Flusberg et al. 1990). Tager-Flusberg (2000) investigated the role of complementation in theory of mind development with older children and adolescents with autism. She found that individuals with autism are more reliant on the syntax of complementation with verbs of communication than with verbs of cognition as an entry point to the understanding of false belief. The Australian children from the present study demonstrated unexpectedly advanced skills in the production of complex sentences, including the use of mental state terms. Moreover, it appeared likely that at least some children possessed an understanding of false belief. Therefore, the data from these children provided the opportunity to investigate this issue with children of a much younger age than were in Tager-Flusberg’s (2000) study, or are generally investigated on the issue of false belief reasoning (Baron-Cohen 1992; Prior, Dahlstrom, and Squires 1990). The data from the present study neither supports nor refutes de Villier’s theory that mastery of the syntax of complementation is developmentally prior to false belief reasoning. As presented in chapter five, the results were mixed. The US children did not produce any complex clauses with verbs of cognition and the profiles of three of the Australian children were consistent with the claim. That is, David and Peter did not demonstrate an understanding of false belief either in the production of false complements with verbs of cognition, or in their interaction with others: the majority of their complement constructions with the verb think seemed to function as opinion markers, and they had reached the understanding that seeing leads to knowing in regard to theory of mind development. Liam did produce false complements with the verb think on three occasions and there was strong evidence to suggest he also understood the concept of false belief. In contrast, the data from Kevin and Joseph appeared to be in conflict with the idea that false belief reasoning is possible only after the syntax of false complements has been acquired. Neither Kevin nor Joseph produced false complements with either the verbs say or think and yet there were specific occasions during the course of the sessions where it appeared they did recognize that people can have thoughts separate from reality, in Kevin’s joke with his mother about there being a spider on her back, and in Joseph’s discussion about the game hide and seek. While it is not possible to make claims either in support of or against de Villier’s theory, an inference can be drawn on the basis of the data from the observational study. Kevin’s and

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Joseph’s apparent recognition of the false belief of another combined with the absence of false propositions implies that knowledge of the syntax of complementation may not be a prerequisite for false belief reasoning. Little comment can be made in regard to Tager-Flusberg’s (2000) claim that it is the syntactic structure of complex clauses with verbs of communication which enable children with autism to reason about false belief. As I discussed in chapter five, there was no clear pattern of development which indicated that complex sentences with verbs of communication were more advanced semantically and syntactically than with cognition verbs. However, the data from Liam did not appear to support Tager-Flusberg’s theory. That is, while Liam produced false propositions with the mental state verb think on three separate occasions, there were no examples of false statements with communication verbs in his data. More particularly, this is despite the presence of at least one situation in which Liam accuses his mother of regularly making false statements, but not within the syntactic framework of complementation as might be expected. This indicates that for Liam, complementation with mental state verbs is more advanced than with verbs of communication, suggesting that perhaps not all children with autism acquire knowledge of false belief via structural mapping with communication verbs. The present study raises some interesting questions regarding the role of complex sentences in the development of theory of mind. While there was no clear overall pattern of results, the data from a number of children appear to be in conflict with the theory that the ability to recognize false beliefs occurs via acquisition of complex sentences with verbs of either cognition or communication. 5.

The origin of grammar: A perspective from autism

The question of whether there is a developmental relationship between language and cognition continues to cause debate among researchers of language acquisition in both typical development and in autism. That is, to what extent, if any, is appropriate cognitive development a pre-condition for language and vice versa. Since problems in social cognition are a diagnostic feature of autism, the linguistic and cognitive development of these children offers a unique contribution to this debate. The critical issue is centred on the question of how children come to acquire knowledge of grammar. Researchers from nativist traditions argue that all grammars of natural language consist of universal principles which

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are innately specified (Chomsky; 1975; 1986; Crain 1991). Within the framework of UG, theorists postulate that children approach the task of language acquisition equipped with a language acquisition device (LAD). The LAD hypothesizes a series of grammars on the basis of the input from the language environment, the final hypothesis being the target grammar (Crain 1991). The hypotheses generated by the LAD are also constrained by the Continuity Hypothesis which stipulates they can only differ from adult grammar to the same extent that adult grammars differ from each other (Crain 1991; Crain and Thornton 1998; Pinker 1984). In contrast, researchers from usage-based models of language acquisition argue that the concept of an innate language faculty is superfluous because it is through the processes of grammaticalization and syntactization that grammatical structures originate (Bybee, Perkins, and Pagliuca 1994; Tomasello 2003). In regard to language acquisition, it is argued that children’s understanding of grammar is derived from the language input they receive, and that they make sense of this input through the general cognitive, social-cognitive and learning skills (Bates and Goodman 1999; Slobin 1973; Tomasello 2003; Van Valin 1986). In the present study, data from the Australian children appear to be consistent with usage-based accounts of the acquisition of complex sentences. As I detailed in chapter five, they possess stronger sociocognitive skills manifest in their theory of mind development, alongside more advanced syntactic development. However, the problems in joint attention demonstrated by the Australian children are not consistent with the idea that their knowledge of syntax is based entirely on the processing of linguistic input. The most interesting data for the purposes of addressing this issue came from Brett and Jack of the US children. These two children (especially Jack) displayed problems with joint attention, as well as a limited understanding that people are intentional beings whose actions are motivated by their desires, emotions and beliefs. In regard to their syntactic development, Brett and Jack display an uneven profile in the acquisition of complex clauses with verbs of desire and cognition. While mental state verbs were found only in the routine expression “I don’t know”, verbs of desire occurred in complex sentences with additional features such as locational expressions (e.g. “I need to go to the closet” (J4: 201)) and negation (e.g. “I don’t want it to break” (B3: 61)), but with only the self as subject. Data of this nature is arguably problematic for usage-based theories of language acquisition. On this approach, one would expect that the grammatical development of Brett and Jack would be uniformly inhibited

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and present with a large number of errors. However, despite their difficulties with social cognition, Brett and Jack display areas of grammatical competence not easily attributed to their ability to attend to, and process linguistic input in the absence of constraining principles such as those provided by the LAD. Moreover, the absence of syntactic errors does not accord with a prediction of usage-based theories, namely, that the acquisition of grammar would be made exceedingly difficult by the social impairments which are a hallmark of the disorder. The data on lexical development does support the claim that social cognition influences acquisition at a vocabulary level. However, the data from Brett and Jack, in conjunction with the syntactic skills demonstrated by the Australian children, do not support the theory that grammatical development is dependent on social and general cognition. The fact that these children by their diagnosis have problems in social cognition, and yet demonstrate quite strong syntactic skills, is more in accordance with idea that the language apparatus is modular (Crain and Thornton 1998). I have addressed in previous chapters a number of usage-based theories, including item-based learning (see section 6.4 of chapter five and above) (Lieven, Pine, and Baldwin 1997; Pine, Lieven, and Rowland 1998) – in particular the Verb-Island Hypothesis (Diessel 2004; Tomasello 1992; Diessel and Tomasello 2001). The common thread to these usage-based accounts is that grammatical development is learned via language input, with a reliance on social-cognitive skills and I have argued that this approach is problematic in the context of the data from this study. A further usage-based theory is connectionism. Various theoretical models have been proposed within this approach (Rumelhart and McClelland 1986; Elman 1990; 1991; Elman et al. 1996), but essentially, connectionism is about explaining human intellectual abilities using neural networks – simplified models of the brain made up of networks of processing elements called nodes or units. These interconnected nodes collect input from a variety of sources: some nodes receive and send input to other nodes; some nodes receive input from outside the system; other nodes send the activation outwards; and there are nodes which perform all three tasks (Elman et al. 1996). The way in which the nodes distribute the input is determined by weighted probabilities which characterize their interconnection with other nodes. Learning is achieved by the network via repeated exposure to examples of the pattern to be acquired. This repeated exposure, combined with internal feedback mechanisms, can change the weighting of probabilities which determine internodal connections. This process is considered analogous to learning. Connectionist networks are considered to

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apply to all situations of learning, including language acquisition. In connectionist models, children learn language on the basis of the linguistic input to which they are exposed. The role of the connectionist network is to engage in inductive learning. All aspects of language are acquired by the network determining generalizations through repeated exposure to the less than perfect input of the language environment. As with all usage-based theories, what sets connectionism apart from nativism is the argument that there is no innate specification for language acquisition in the human brain. Elman et al. (1996) argued that what is known about brain development means it is unlikely that Universal Grammar could be genetically encoded. Connectionism has been applied to many aspects of language acquisition, including lexical development and grammatical development (Rumelhart and McClelland 1986; Elman 1990; 1991; Lewis and Elman 2001). Saffran, Aslin, and Newport (1996) investigated whether the performance of eight-month-old babies in a word discrimination task indicated behaviour suggestive of inductive processes. A network had been designed, described in Elman (2001), which included a basic memory and predictive powers enabling it to successfully predict the next letter in a string of letters on the basis of statistical regularities in the input. Saffran, Aslin, and Newport (1996) found that when these infants listened to a string of nonsense three-syllable words, they were able to discriminate between the old string and a new string with the same syllables in a different order on only a few minutes exposure. The authors argued that this was evidence for behaviour much like the predictive network. Lewis and Elman (2001) investigated whether a network could be created which would learn complex structures of the kind “Is the boy who is smoking crazy?” from exposure restricted to less complex structures, and thus allow argument that children learn syntactic patterns on the same basis. Previous research had revealed that networks can learn abstract grammatical structure (Elman 1993), and Lewis and Elman’s simulation showed that a network can predict a sentence it has never encountered on the basis of the input. Therefore, they concluded that since children appear to be cautious in their early production of syntax, it is entirely conceivable that they are learning the grammar of the linguistic environment using similar inductive processes as the artificial network. Connectionist accounts are difficult to reconcile with the profile of linguistic and cognitive abilities in children with autism. One of the basic premises of connectionism is that all knowledge is acquired via the same general inductive processes (Elman et al. 1996). In the context of the present study, some of the children with autism displayed surprisingly

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advanced semantic and syntactic development which is hard to explain under a connectionist account of language acquisition. If all human cognitive abilities are acquired via the same general mechanism, then how is it that children with below normal intelligence can demonstrate surprisingly advanced linguistic knowledge, as in the Australian children of the present study; or demonstrate language development that is within the normal range (Kjelgaard and Tager-Flusberg 2001), despite below normal intelligence? Previous research has demonstrated that while some aspects of linguistic development are affected by cognitive impairments in autism, grammatical development is not (Tager-Flusberg 1994). Moreover, Smith and Tsimpli (1995) found that typically developing young adults could not learn a structure independent rule (such as add a suffix to every third word of a sentence to indicate emphasis) in the context of a language learning task, despite being able to perform comparable tasks in a non-linguistic context. They concluded that structure dependence and modularity are critical for language learning, and are not outcomes of the process of language acquisition. In sum, connectionism does not appear to offer an adequate account of the language abilities of the Australian children from this study. A final matter to consider is the clear variation in the rate of acquisition of verbs and prepositions between the children, as represented in the developmental flowcharts of chapters three and four. Under usage-based approaches, the acquisition of lexical and grammatical elements is asynchronous, and is a gradual process (Bates and Goodman 1999; Tomasello 2003). The question needs to be considered, then: are these results incompatible with Universal Grammar, pointing instead to some type of usage-based approach? While the variation in development is irrefutable, the results are not inconsistent with generative approaches. Firstly, the variation in rates of development can be, at least in part, attributed to the population group. The heterogeneity of the disorder means that the children are inevitably located on different points of the spectrum, with some being higher functioning than others, and this is reflected in their language development (Kjelgaard and Tager-Flusberg 2001; Prior et al. 1998). Secondly, these flowcharts represent lexical development, which is considered a separate domain to grammatical principles such as those discussed above (Grinstead 2000; Pinker 1999). The fact that some aspects of the grammar are lexical (such as modals and determiners) is often taken as evidence that grammatical development is gradual (Bates and Goodman 1999). However, this overlap is not inconsistent with Universal Grammar in which the lexicon consists not just of semantic information, but also

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phonological and grammatical information (Chomsky 1995; Grinstead 2000; Smith and Wilson 1979). These elements are separate from the computational aspects of language proposed by nativists. In summary, the data from the present study are not compatible with the idea that all language develops as a result of general cognitive growth. While the data support the view that lexical development is influenced by social cognition, the data also suggest that syntactic development is, at present, better explained by a theory of Universal Grammar. TagerFlusberg, Paul, and Lord (2005) observed that individuals with autism are less skilled in their ability to manage discourse than would be expected on the basis of their syntactic abilities. Tomasello (1999) acknowledged the unique difficulties experienced by individuals with autism in regard to their limited skills in social cognition. However, the fact that there are individuals with autism who develop language skills on a par with typical development poses problems with usage-based accounts which are yet to be addressed. 6.

Final comments

A number of important findings from the study are worth highlighting. A key result of the investigation into the semantic development of verbs and, by extension, prepositions was the evidence in favour of a profile of semantic development which accords with typical development. Moreover, the extent to which the Australian children, especially, had acquired advanced semantic concepts argued to be problematic for children with autism was a surprising feature of the data. That is, it was not expected that categories encoding abstract meanings, especially internal states, would be as well developed as they were in the language of some of the children. Moreover, the surprising extent to which some of the children demonstrated awareness of semantic knowledge was revealed in the presence of lexical innovations which indicated an engagement with covert semantic categories. Additionally, the small percentage of misuses recorded in the data of each child provided further evidence against a theory of atypical development. Another noteworthy result was the unexpected theory of mind abilities of many of the Australian children, which revealed that children with autism who are much younger than previously supposed are capable of recognising that people can have beliefs which are separate from reality. Furthermore, the unexpected grammatical competence of many children in

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the study was in contrast to the pragmatic difficulties and often poor joint attention identified in the transcripts and during the course of the elicitation tasks. This pattern of development is problematic for usage-based theories: skills in social cognition which must be impaired for a diagnosis of autism are the very skills on which usage-based theories are contingent. In contrast, despite the presence of other cognitive impairments, the modularity of the language apparatus proposed in Universal Grammar in combination with the LAD give an account consistent with the development of grammatical skills observed here. While some pertinent results arose regarding the semantic and syntactic development of verbs and prepositions in the language of children with autism from the present study, I must acknowledge that there are limitations on the extent to which conversational data can allow comprehensive investigation of the issues targeted. As other researchers have cautioned, correct contextual use of a lexical item may be purely incidental and may not mean the speaker possesses full semantic knowledge of the word (Leekam 2007: 121; Perkins et al. 2006: 800). A difficulty with naturalistic data on the issue of verb use and complex sentences is that the absence of a particular construction from such language samples does not necessarily entail its absence from the grammar of the individual child. A series of experimental studies are reported in Douglas (2007) in which I examined the extent to which the Australian children with autism from the present study demonstrated knowledge of grammatical processes in the production of complex wh-questions. Notwithstanding the limitations of the research design acknowledged above, there are some interesting theoretical implications from the study which I review here. For the semantic development of verbs and prepositions, a number of issues were raised by the data. One issue is that theories which postulate a path of atypical development for the acquisition process were not supported by the data. Rather, the profile of semantic development for these relational categories accords with the profile of typical development and is consistent with earlier studies on the acquisition of object labels in children with autism in which similar conclusions were reached. While verb development may be significantly delayed, or even plateau, the order in which the various sub-categories of verbs and prepositions are acquired does not appear to deviate from typical development. A second issue relates to the rate of development as observed in the present study. The considerable variation between the children regarding the extent to which they had acquired the semantic categories of verbs and prepositions was not accounted for by age, Performance IQ or

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language development as measured by MLU. I argued that theory of mind development appeared to influence the acquisition process: the role of social cognition in lexical development is well established in studies on typically developing children, and the results of the present study contribute to the body of literature investigating the effect of social cognition on lexical development in children with autism. A number of possible directions for future research arise from the results of the present study. Since the analysis of verb acquisition was based exclusively on production data, a study examining verb comprehension in children with autism across the range of subcategories within this word class would be of interest. This would add to the profile of semantic development determined in the present study as well as address the limitations of conversational data outlined above. Another area which warrants further investigation is the relationship of verb acquisition to theory of mind development. While the data from the study were certainly suggestive of a link between social cognition and verb development, a more systematic investigation of this relationship would clarify the extent to which theory of mind affects the rate of verb acquisition. As verb acquisition in children with autism is an area of language development about which there is much still to learn, I hope this monograph can offer a contribution to advance our understanding of this process, and possibly stimulate further research.

Notes 1. 2. 3. 4. 5. 6. 7.

MLU scores of Liam, Kevin and Joseph are recorded as 4+ since the usefulness of MLU as a measure of grammatical complexity decreases after Stage V of language development (Brown 1973). Percentages for activity verbs also include verbs of motion. Tager-Flusberg’s (1992) study was based on the full set of transcripts sourced for the present study. As discussed in section 3.6, Stuart’s use of the emotion verb like is anomalous and not indicative of his general profile. This study used the large data sample from which four sessions per child are used for the present study. Only the verb say was sufficiently well represented in the data to allow analysis. It must be noted that the beginning point of the developmental stage reached by each child is not known, making it impossible to speculate on the ageequivalence in typical development for the children.

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Index

Asperger, Hans, 14, 15, 16, 17, 18, 19, 24, 42 Asperger Syndrome, 35, 41, 42 associationism, 3, 8 and autism, 39 autism aetiology, 23 prevalence, 23-24 definition, 24-25, social recognition, 20-21 social communication, 21 social imagination, 21-22 triad of impairments, 19-22

deixis, 1, 37, 46, 47, 56-58, 82, 85, 86, 87 see also verbs pronoun reversal, 16, 37, 56 diagnosis of autism, 15, 17, 18, 19, 20, 22, 34, 39-42 ADI, 41, 42, 171 DISCO, 41-42 ADOS, 42, 171 CARS, 10, 42 DSM-III, 9 DSM-IV, 9, 40-42 DSM-IV-TR, 40

Baron-Cohen, Simon, 28, 30, 32-33, 39, 48, 51, 72, 144 Bates, Elizabeth, 130, 153, 178, 181 biases and constraints, 4, 5, 7, 8, 155 Bloom, Paul, 2-3, 4, 6 Bowerman, Melissa, 84, 94, 96

Echolalia, 11, 16, 34, 36, 45, 106, 123, 157 executive function, 30-34 Wisconsin card sorting test, 31 Tower of Hanoi, 31-32, 32

categorization, 3, 4, 8, 11, 86-87, 91, 96, 100, 105, 129, 147, 153, 161, 164, 167, 168, 173, 174, 183, 184 categorization deficit, 1, 37 central coherence, 33-34 embedded figures test, 33 Chomsky, Noam, 154-155 Clark, Eve, 4, 56, 72, 83, 100, 106 complex sentences semantic development, 12, 60, 130-160, 162-163, 176, 177, 178 syntactic development, 11, 12, 60, 67, 130-160, 162-163, 176, 177, 178, 180, 183

ICD-10, 40-42 Index of Productive Syntax, 35, 151, 157 intention/intentionality, 6, 28, 44, 48, 50, 60, 78, 79, 130, 153, 158, 168, 171, 172, 174, 175, 178 internal states, 11, 45, 53, 59, 61, 74, 75, 84, 91, 182 see also psychological states IQ tests, 25-26, 33 Leiter International Performance Scale, 9 WPPSI-R, 10 WPPSI-III, 10 WISC, 26, 33

Index joint attention, 38, 50, 124, 129, 143, 144, 145, 146, 153, 157-158, 159, 160, 169, 178, 183 and vocabulary development, 5, 8, 38, 168, 169-170 Kanner, Leo, 14, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 36, 39, 42, 75, 93, 100, 163 language acquisition in autism morphology, 10, 35-36 phonology, 35 pragmatics, 36, 39, 89, 157, 158, 170, 183 prosody, 35 syntax, 35, 36, 130-160, 163, 175-177, 178-182 language comprehension in autism, 36, 37, 38, 48, 53, 61, 70, 71, 75, 151 Leekam, Susan, 30, 32, 38, 143, 169, 183 lexical innovation, 83-84, 91, 163-164, 182 Lord, Catherine, 34-35, 37, 86, 182 mean length of utterance, 9, 10, 11, 46, 48, 88, 90, 91, 92, 95, 98, 128, 157, 165, 166, 167, 184 Menyuk, Paula, 1-2, 48, 51, 59, 75, 86, 100, 105, 119 metaphor, 75, 76, 100, 101, 102, 104, 105, 122, 123, 127 mirror neurons, 170 and autism, 171, 172 and verb learning, 171 modal verbs, 47, 59, 78-81, 181 and autism, 79 deontic, 78, 79, 80 dynamic, 78, 79-80 epistemic, 78, 79, 80-81

223

quasi-modals, 78, 79, 80, 83 root, 78 overextension prepositions, 117-118, 119, 121, 129, 162 verbs, 81-82, 83, 163-164 perspective-taking, 46, 56, 58, 75, 150 see also self and other prepositions abstract, 95, 102-105, 109, 110, 114-115, 119, 122-123, 127 aspectual, 95, 104-105, 118119, 121 grammatical, 95, 105-107 misuses, 95, 107-109 particles, 94, 96, 105 projective relationships, 96, 99, 99, 127 spatial, 95, 95-99, 109-111, 114-115, 118-120, 122-126, 127, 162, 165 temporal, 95, 100-102, 110, 114, 122, 127 Principle of Contrast, 4 Principle of Conventionality, 4 psychological states, 1, 38, 44, 71, 142, 161, 163, 171, 172 self and other, 56, 59, 69, 132, 136, 139, 142, 178 sensorimotor perception, 3, 8, 11, 45, 48, 53, 91, 161, 164, 172 social cognitive skills, 5, 11, 13, 14, 19-21, 26, 27, 30, 35, 37-38, 39-42, 45, 53, 68, 77, 78, 85, 125, 153, 156, 157-160, 167170, 172, 179, 182, 184 social-pragmatic theories, 4-5, 39, 153, 155, 156-160, 178-179, 183

Index 224 see also theories of language acquisition; usage-based theories Specific Language Impairment, 89, 148, 158, 175 Tager-Flusberg, Helen, 1, 9, 35, 36, 56, 67, 70, 79, 86, 89, 139, 144, 151, 157, 158, 166, 176, 177, 182 theories of language acquisition connectionism, 179-181 Language Acquisition Device, 155, 178-179, 183 nativist theories, 154-156, 159-160, 182 Universal Grammar, 154-58, 177-178, 180, 181-182, 183 usage-based theories, 153154, 158-160, 163, 178-182 Verb Island Hypothesis, 153 theory of mind, 5-7, 8, 27-30, 37-39, 70, 75-76, 143-147, 167-170, 182 and lexical development, 5-6, 7, 8, 37-39, 167-170, 173-175 and syntactic complements, 147-152, 175-177 false belief, 28-30, 76, 136137, 143-144, 145, 146-152, 160, 175-177 first order theory of mind, 30, 75-76 pretend play, 143-144, 145, 146 Sally-Anne task, 28, 29 second order theory of mind, 30 Tomasello, Michael, 5-6, 51, 94, 106, 107-108, 135, 147, 150, 153-154, 168-169, 178, 182

underextension, 96, 109, 113, 121, 126 verb diversity, 49-50, 52-53, 55, 58, 60, 63, 65-66, 69, 71, 74, 77, 79-80, 88-91 verbs in typical development, 7-8, 44, 47-48, 51, 53, 56, 58-59, 61, 64, 67, 70-71, 72, 75, 78, 82, 83-84 verbs abstract, 47, 75-77, 85, 87 activity, 47, 47-51, 85, 87 causative, 47, 72-75, 85, 87 change of state, 47, 51-53, 85, 87 communication, 47, 67-69, 85, 87 deictic, 46, 47, 56-58, 85, 87 desire, 47, 58-61, 85, 87 emotion, 47, 61-64, 85, 87, 86-87 general purpose/light verbs, 49, 77, 112, 116, 122, 165 mental state, 47, 61, 63-64, 69-72, 85, 87 misuses, 47 81-83 modal, 78-81 overextensions, 81-83 perception, 47, 64-67, 85, 86, 87 stative, 47, 53-56, 85, 87 de Villiers, Jill, 135, 147-148, 150, 175 Wild Boy of Aveyron, 13 Wing, Lorna, 18, 19-22, 41