Syntactic factors in memory? 9783111729169, 9783110996852

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JANUA LINGUARUM STUDIA MEMORIAE N I C O L A I V A N WIJK D E D I C A T A edenda curai C. H. VAN SCHOONEVELD Indiana University

Series

Minor,

168

SYNTACTIC FACTORS IN MEMORY?

by SAMUEL

FILLENBAUM

University of North Carolina, Chapel Hill

1973

MOUTON THE HAGUE • PARIS

© Copyright 1973 in The Netherlands. Mouton & Co. N.V., Publishers, The Hague. No part of this book may be translated or reproduced in any form, by print, photoprint, microfilm, or any other means, without written permission from the publishers.

Printed in the Netherlands by ZND, 's-Hertogenbosch.

PREFACE

This monograph seeks to assess the role of syntactic factors in memory, and much of the discussion will be concerned with justifying the question mark in the title. Two theses will be central to the presentation. I shall argue first that those who have studied memory for sentences generally have not been interested in memorial processes but only in using memorial data to provide information about the ways in which syntactic structures might be cognitively represented, and that there are very serious problems in drawing inferences about memorial processes from such studies, and second that there are good grounds for believing that sentence memory rather than being syntactically based is actually semantically based. The monograph is a revised and expanded version of a chapter 'Syntactic Factors in Memory' which appears in Current Trends in Linguistics, vol. 12, ed. by T. A. Sebeok. The principal addition to the earlier essay is a section titled "Memory not for sentences but for knowledge based on the information in sentences". The present work was supported in part by United States Public Health Service Grant MH 10006 from the National Institute of Mental Health. Samuel Fillenbaum Department of Psychology University of North Carolina Chapel Hill, N.C. July 1, 1972

CONTENTS

Preface

v

0. Introduction

1

1. Problems of inference from memorial data

5

2. Effects of some syntactic variables

13

2.1 Some consequences of syntactic malformation . . . 2.2 Learning and memory for well formed sentences . . 2.21 The role of surface structure 2.22 The role of deep structure 2.3 The processing of multiply self-embedded sentences .

13 19 19 23 42

3. Sentence memory as semantically based 3.1 Errors as meaning preserving 3.2 An example of some properties of a semantic representation relevant to sentence memory 3.3 Memory not for sentences but for knowledge based on the information in sentences

52 54

4. Models of human memory and memory for sentences

78

.

61 66

5. Coda

87

References

88

Author index

95

Subject index

97

0 INTRODUCTION

Much recent work in psycholinguistics, where "recent" refers roughly to the last decade, has been devoted to assessing the psychological reality and determining the cognitive representation of syntactic structures. The use of memorial techniques has been incidental to this purpose, with various memorial tasks used more or less casually as convenient if indirect devices to this end. The interest has not been in the ways in which syntactic factors might influence memorial processes or performance, but in the yield of memorial tasks as revealing something about syntactic structures, the memory systems characteristically being regarded as simple transducers of information which do not introduce any properties or biases of their own. Thus, to speak of "Memory" is misleading because the bulk of the work has really not been concerned at all with memorial problems. If one is concerned with memory then there are grounds for believing that semantic rather than syntactic factors may be of crucial importance, with syntactic factors relevant only insofar as they are necessary for determining the meaning of a given sentence, which, in some form, is what is stored. Thus, if one is really interested in problems of memory, to speak of "Syntactic Factors" may be misleading because the significant factors may be semantic ones. The above, if correct, may be taken as providing some justification for the question mark in the title of this monograph. One of the main purposes of this discussion will be to present evidence in support of the foregoing general contentions. In addition we shall seek to spell out some of the problems that arise when one attempts to assess underlying structures by use of memorial techniques which provide information simultaneously about putative properties of

2

INTRODUCTION

syntactic structures and about putative properties of memorial processes, and thus essentially block unequivocal inferences about either. In the course of that discussion we shall try to indicate some of the conditions that must be met, and which characteristically have not been met, in order to support legitimate inferences about memorial processes. Finally, we shall indicate why it would be difficult, if not impossible, to apply any of the recently developed models of human memory in a substantive way to the study of sentence memory. Before actually looking at examples of syntactic studies employing memorial techniques, a few general observations on the (experimental) psycholinguistics of the 1960's might be in order. If we distinguish between developments internal to psychology and external ones, i.e. ones stemming from linguistics, then it is clear that the decade was one of external determination. While there was some work generally concerned with syntax as an organizing factor, and while toward the end of the decade there was work which sought to demonstrate the importance of imagery in language (see e.g. Paivio, 1970), the most important influences certainly came from developments in linguistics. Further, with regard to the nature of such influences, while there was some research prompted by Yngve's phrase structure model (see e.g. Martin & Roberts, 1966) and some talk at least prompted by Lamb's stratificational grammar (see Reich, 1967; Reitman, 1969) it is clear that overwhelmingly the most important influence was due to developments in transformational generative grammar. Here the landmark works were Chomsky's 1957 monograph (Syntactic Structures) and 1965 book {Aspects of the Theory of Syntax). Developments since 1965 whether in Chomsky's own position (e.g. Chomsky in Steinberg & Jakobovits, 1971) or as represented in the work of people such as Fillmore, Lakoff, or McCawley have, as yet, had little real impact on experimental work in psycholinguistics. In all this traffic from linguistics to psychology the single most important individual has been George Miller, in terms of his own work, in terms of the work of his students and in terms of the persuasiveness of the arguments he addressed to his colleagues. Indeed his 1962 paper ("Some

INTRODUCTION

3

Psychological Studies of Grammar") first acquainted psychologists with some of the implications of developments in transformational grammar, and in a sense set or posed the problems which have engaged psychologists ever since, both with regard to the sort of underlying representation in which a sentence might be held in memory and with regard to the processes by which such underlying representations might be derived or determined from surface structures. Some feeling for the kinds of changes that have occurred in psycholinguistics in the 1960's at least with regard to an enormously greater sophistication concerning the issues we must face, if not with respect to any firm solutions, can be obtained by comparing Miller's seminal 1962 paper with Watt's magisterial review of issues in 1970. Or, to the same end, one may compare the arguments to be found in Mehler's 1964 Harvard dissertation, which constituted one of the first extensive studies influenced by work in transformational grammar with the vastly richer and more complex account to be found in Wanner's impressive 1968 Harvard dissertation. In the present essay while we shall restrict ourselves to studies using memorial techniques of various sorts we will not consider the study of structured sequences whose members or items are semantically empty. Thus we shall not be concerned with the learning or memory for syntactically structured nonsense strings i.e. nonsense strings where some functors, bound morphemes and surface-order-like relations have been introduced. For the classical study in this area see Epstein (1961), for a recent review and overview which argues that facilitation of recall through the introduction of linguistic structures is "a well-established though delicate effect" see O'Connell (1970). Nor shall we consider research in the learning of miniature artificial languages, which work may be regarded as the study of rule governed behavior in the case of specially contrived highly simplified and arbitrary, semantically empty micro-systems. An examination of the distribution of intrusions in free recall and of false positives on recognition tests in such studies of 'verbal reconstructive memory' suggests that subjects can indeed abstract certain regularities or structural properties

4

INTRODUCTION

of the presented materials and use these abstract representations to reconstruct what was presented. Attempts have been made to model in this context analogues to various simple linguistic rules including surface structure relations, transformational relations, and selectional restrictions. While the fact that various sorts of 'syntactic' properties, which are the only orderly relations obtaining here, may influence memorial performance when subjects are dealing with these semantically empty miniature systems is of considerable interest, it is not completely obvious what implications this may have with regard to the ways in which listeners cope with natural language materials derived from vastly more complex and semantically fraught systems. For a very valuable review of this work and its possible implications see Smith & Braine (in Bever & Weksel, in press). The following plan will be followed in the body of this monograph. We shall begin by noting some of the difficulties attendant upon any attempt to draw inferences either about memorial processes or about underlying syntactic structures solely on the basis of data yielded by memorial techniques and then, with these considerations in mind, we shall examine some examples of syntactic work falling into each of the principal sub-areas or dealing with each of the principal problems that have occupied psycholinguists in recent times. Next we will review some evidence that strongly suggests that sentence memory may be semantically based, indeed that memory may not be for sentences but rather for knowledge based on the information in sentences. And finally a consideration of the scope of current models of human memory will reveal why such theoretical accounts may not be useable by the psycholinguist interested in the study of memory for sentential materials.

1 PROBLEMS OF INFERENCE FROM MEMORIAL DATA

Right at the start it is necessary to emphasize a point already mentioned: psycholinguists have characteristically been concerned with the study of underlying syntactic structures not with the processes involved in memory for these structures. Most commonly they have not even explicitly discussed problems of inference from memorial data, and when they have, generally it has been only to note that there might be problems in drawing conclusions about putative underlying structures. To take an example, Wanner, in his dissertation (1968) points out: that it may be perilous to base inferences about the products of comprehension upon the contents of long term memory. The problem is that such inferences require the assumption that long term memory is a fairly veridical system of storage.... Human memory may be unstable losing or adding information with time... it may not store all information available from the comprehension process. Moreover long term memory may impose an organization of its own upon the information which it does retain... facts about memory do not require conclusions about comprehension. As another example, consider that Fillenbaum (1970) argues that "the distribution of confusions or errors on a memorial task cannot be considered as directly revealing of the structures underlying the string memorized, or of the similarities between such structures", without giving anything near as much attention to the fact that, equally, such findings cannot say anything directly about the nature of the memorial processes involved. Given such a concentration of interest it should not be surprising that psychologists have been very casual, not to say cavalier, in their use of memorial techniques. If such techniques are simply devices of convenience

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PROBLEMS OF INFERENCE FROM MEMORIAL DATA

to get at underlying structures then, more or less indifferently, one might employ a procedure involving a long term memory or a short term memory task, one might use recognition or recall techniques, one might use free recall or one might use prompted recall, one might use intentional learning tasks or incidental ones, one might present materials in one modality or another, etc. All this without worrying overmuch as to whether results might be contingent upon particular properties of the tasks involved. Since, insofar as the issue has been raised at all, it has been raised with regard to the 'use of memorial techniques to assess syntactic structures' we shall consider it in this form, with the caution only that the general problems that arise here necessarily arise equally when one wishes to draw inferences about memorial processes from such data. Why are there difficulties in using data gathered by memorial techniques to make inferences about underlying syntactic structures? The principal general reason is simply that such data provide information simultaneously about possible underlying structures and about memorial and retrieval (or perhaps reconstructive) processes, and characteristically it will not be possible to factor or decompose such information into its component parts. If there were strong constraints from a relevant theory of memory then, in principle, one might be able to deduce the properties of the object upon which these constraints operated to yield the output obtained. But no such powerful and relevant models of human memory are available. Equally, if one knew what a sentence was as an object of memory, then one might be able to draw some conclusions as to the nature of the memorial processes involved. But, of course, we do not know what the cognitive representation of a sentence might be like, and the major purpose of most of the studies to be considered was to attempt to discover this (indeed, had this been known already they would not have been done in the first place). We are only making the very obvious point that one equation in two unknowns does not yield a unique solution for those unknowns — obviously further constraints must be imposed. There are, of course, difficulties above and beyond this very general one. It may well be the case that the way in which a sentence

PROBLEMS OF INFERENCE FROM MEMORIAL DATA

7

is analyzed and stored in a memorial task may be quite different in important respects from the ways in which it is processed under normal circumstances or ones that require full understanding. One cannot even be sure, in general, that the subject has made a fairly complete analysis of the linguistic materials, and one must wonder about the effects of task instructions which tell him that verbatim recall or recognition will later be required. The most common way of presenting the materials "as lists of sentences in tasks which do not require understanding or use of the information in the sentences, may result in something much closer to parroting of words than complete structural analyses of sentences" (Fillenbaum, 1970). We must be alert to the possibility that often results may be as much a consequence "of special ad hoc strategies adopted for coping with particular laboratory tasks as of anything else, and that often subjects may not at all be dealing with what we want them to deal with and what we think they are dealing with" (Fillenbaum, 1970). This last, of course, is the issue involved in the general distinction between the nominal stimulus as defined by the experimenter and presented to the subject, and the functional stimulus as referring to those characteristics of the stimulus which the subject actually uses or selects to cue his responses. Consider one of many possible examples. If all sentences in a learning and recall task are of the surface form 'They are verb-ing N-pl', subjects may treat such items not as sentences but as nominalizations involving just the last two words, leading to quite different predictions from those that would have been made if full sentences were being processed; in the particular instance just cited (Rohrman, 1968) the author was sensitive to this possibility. To make sure that each sentence is fully comprehended one must force the subject to attend and process the materials. One possibility is to employ the sort of procedure used by Blumenthal & Boakes (1967) where two context sentences always preceded each critical sentence, and the subject was always required to paraphrase the critical sentence before repeating it a number of times in its original form (eventually he was required to recall it given a prompt word). While one cannot know what the results of the analysis were, with such a procedure

8

PROBLEMS OF INFERENCE FROM MEMORIAL DATA

at least one can be reasonably confident that a fairly full syntactic and semantic analysis was, in fact, performed. Comparable procedures will not always be possible, and certainly, possible or not, have seldom been employed. And note that if there is no guarantee that the sentence was initially comprehended then, even if we could decompose memorial data into their two sources, the results are hardly likely to be of any general interest since they would reflect the operation of memorial processes upon some object which stands in a quite indeterminate relation to the object in which we are actually interested (and given this queer or at least possibly very different sort of object there are not even compelling grounds for believing that the same sort of storage and retrieval processes are involved as might have been involved had the subject been dealing with a properly understood sentence). One can now indicate, in a very rough general way, the sorts of conditions that must be met if the results of studies using long term memory techniques are to be revealing regarding the role of syntactic factors in memory — basically what is called for are multiple assessment procedures. Thus for a given sentence one needs to use (1) some more or less direct procedure shortly after presentation in order to determine how it has been encoded and what its representation may be, i.e. what it may be as an object for memory. Such a procedure must itself satisfy a number of conditions (a) it should not be such as to permit some sort of 'echo box' response where the subject simply repeats back 'the relatively unanalyzed contents of a preliminary store', but rather (b) it should be such as to require full understanding of the sentence forcing the subject to analyze it carefully and to attend to nuances in meaning. Essentially what is needed is some task such as paraphrasing, question answering, drawing of inferences, following instructions, sentence verification, or whatever, successful performance of which guarantees that understanding has actually occurred, and where (c) the yield of the task is itself informative as to the nature of the object that is being input to long term memory. This last is perhaps the most difficult and the most essential of the conditions to satisfy since one needs to be sure not only that a sentence has been under-

PROBLEMS OF INFERENCE FROM MEMORIAL DATA

9

stood but also one needs to know how it was understood — which of its properties that understanding is sensitive to. It is precisely because of difficulties in this respect that experimenters have so often resorted to memorial techniques on the assumption, often tacit, that long term sentence memory must depend on comprehension and therefore ought to be informative about comprehension. If one is interested in (longer term) memorial processes then (2) one needs to determine the fate over time of the object of memory. This immediately raises questions regarding the time elapsed between initial presentation and assessment and the final assessment, regarding the (other) events occurring during that interval, regarding the subject's expectations as to whether or not there would be a long term memory test (i.e. whether the task is an intentional or incidental one), regarding the ways in which such a test is actually carried out, e.g. whether the task used is a recognition task or a recall task and, if a recall task, whether free or prompted recall is involved, regarding possible modality effects, etc. Obviously all or any of these may be significant determinants of the results of the long term memory test and one needs to determine the ways in which they are of consequence. Now given the results of the more immediate, direct assessment and those of the longer term memorial assessment, comparisons between them presumably will provide the relevant information as to the possible role of syntactic factors in (long term) memory. Insofar as the results are parallel, one may infer that the memorial processes have not imposed any properties of their own and that the differences obtained are due to differences in the structures involved in the initial understanding of the sentences. Thus, for example, if sentences differ in comprehensibility and such differences are directly related to differences in retention one might interpret the latter result in terms of the former. On this logic what would presumably be of particular interest would be discrepancies between the results of the immediate and those of the longer term determination, and the sorts of discrepancies obtained should provide clues as to the ways in which syntactic factors may affect memory.

10

PROBLEMS OF INFERENCE FROM MEMORIAL DATA

Given such interesting discrepancies then (3) one requires some well specified models of human memory which are relevant to and may articulate with these findings, such that the findings may be interpreted in terms of the models and that the findings are relevant in permitting us to choose among the models. The above is a grossly simplified sketch indeed, and each of the points mentioned in passing produces its own impressive set of difficulties. To expand briefly on only one of these, consider the possible consequences of the fact that most memorial studies have been ones where the subject knew in advance that his verbatim memory for the sentences would be tested. In many ways this constitutes a quite extraordinary task, not to say one which is rarely if ever required and literally quite impossible given not single sentences but the longer stretches of connected discourse encountered in everyday circumstances, where what is important is the sense of what is said, not the particular constellation of words in which the message is embodied. Thus it might well be the case that subjects told that they will be required to recall word-for-word may adapt "a special strategy to remember syntactic detail" (JohnsonLaird, 1970). If this is so, then even if syntactic factors do appear to figure in memory this may be a consequence, perhaps more accurately an artifact, of the kinds of tasks conventionally employed. There is research by Tieman (1971) on recognition memory for comparative sentences which is relevant here. Working on the hypothesis that "what is remembered can be radically affected by the strategies employed in order to cope with the requirements or presumed requirements of the moment" Tieman manipulated these requirements by systematically varying instructions to the subjects, some subjects being led to believe that they had to remember the exact wording of sentences, others that memory for meaning was the important thing. All subjects were told that they would be presented a long list of sentences and that afterward they would be tested on the content of the sentences. Subjects in a Visual Imagery condition were told to remember the sentences by forming a "visual image" of the relations in the sentences, not to worry about the

PROBLEMS OF INFERENCE FROM MEMORIAL DATA

11

wording, but just to get the meaning. Subjects in the Gist condition were told to remember the "gist" or "meaning", that they would only be tested on the meaning and not to pay attention to exact wording. Finally, subjects in the Exact Wording condition were told they would be tested on the exact wording "and that they should not be fooled by sentences which meant the same thing but were worded differently". After the presentation of the sentences all subjects were given a multiple choice recognition test and "told to check the verbatim correct answer for each set". The principal effect of instructions was on the nature of the errors made. Subjects in the Visual Imagery condition chose the distractor which maintained the correct meaning as did the subjects in the Gist condition (if not as consistently as the former subjects). On the other hand subjects in the Exact Wording condition tended to choose the distractor which maintained correct noun order but not correct meaning. This general pattern of recognition errors produced by instructions held for three different experiments. Results such as these are obviously subversive, and properly so, for they suggest that one cannot simply treat different sorts of instructional conditions as equivalent, that Johnson-Laird's speculations mentioned above may be well founded, and that there may be no warrant for generalizing results obtained in the most commonly employed paradigm for sentence learning and memory, where learning is intentional and instructions are usually for verbatim or exact wording memory (whether phrased so explicitly or by implication), to the circumstances of everyday life where, insofar as learning is intentional at all, the self instructions are much more likely to be meaning or gist instructions than verbatim instructions, except for extraordinary cases such as actors trying to memorize their lines. Note that Tieman's results were obtained under intentional conditions and that, of course, such conditions might yield results different from those that might be obtained under the perhaps ecologically more representative conditions of incidental learning or memory. In some ways the intentional/incidental contrast is surely a confounded one, since characteristically one will be comparing results obtained under verbatim instructions in an intentional

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PROBLEMS OF INFERENCE FROM MEMORIAL DATA

condition with results obtained under unspecified (self) instructions in an incidental condition. Such (self) instructions, insofar as they are specifiable at all, probably come closer to meaning or gist instructions than to exact wording or verbatim instructions. All the above is to raise questions only with regard to input conditions, to say nothing yet as to the ways in which memory is to be tested. In any case, to return to the general point, it seems clear that the conditions we have described as necessary ones are not satisfied in the work that has been accomplished, and what is worse, that it is by no means clear how they could have been satisfied. Nevertheless we may find these conditions or criteria useful in providing a methodological perspective on the work that has been done.

2 EFFECTS OF SOME SYNTACTIC VARIABLES

We may now consider some of the relevant research, looking in a very selective fashion at a few studies. First we shall note some of the effects of syntactic malformation, then examine performance for various cases of syntactically well formed structures which are intelligible, and finally consider a structure which is syntactically well formed but characteristically also quite unintelligible.

2.1 SOME CONSEQUENCES OF SYNTACTIC MALFORMATION

If in some fashion or other syntactic structure serves to organize a string, then degradation of that structure should make processing more difficult, and thus impair various sorts of performances. This is the logic that motivated a study by Marks & Miller (1964) on "The role of semantic and syntactic constraints in the memorization of English sentences". They constructed four kinds of strings: (a) normal sentences, (b) semantically anomalous sentences, i.e. sentences which are senseless but syntactically structured, (c) sentence anagrams constituted by scrambling word order in normal sentences, and (d) word lists comprised of haphazardly arranged unrelated words (actually obtained by scrambling the word order of semantically anomalous sentences). These strings were presented to subjects for five learning trials, each learning trial being followed by a free recall test. A number of different ways of scoring the results were employed and, in each instance, performance was distinctly best for normal sentences and worst for word lists, with semantically anomalous strings and anagram strings falling intermediate. Performance on anagram strings was slightly better than

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EFFECTS OF SOME SYNTACTIC VARIABLES

that for anomalous strings if percent of total words correct is considered (regardless of order errors), while performance on anomalous strings was definitely better if one considers the proportions of complete strings correctly recalled. This last finding is sensible enough bearing in mind that if the subject had understood the meaning of the sentence distorted in the anagram string he might well recall many of the words but not necessarily in the order in which they were presented, which would yield a relatively high word score and a relatively low sentence score. In terms of these over-all results and in terms of a more detailed analysis of the nature of the errors made Marks & Miller conclude that the "results demonstrate a differentiation between semantic and syntactic factors and a facilitatory effect of both on learning". It should be pointed out that the differentiation between semantic and syntactic factors is not a completely clear one, since the semantically anomalous strings were ones which violated all sorts of selection restrictions. Whether the constraints expressed in selection restrictions are to be considered as syntactic or semantic dependencies is of course currently at issue — see, e.g. McCawley (1968) who argues strongly for a semantic basis. Note further that the nature and the locus of the effects obtained by Marks & Miller is left indeterminate. Do the results represent differences in retention or only differences in the reconstructibility of the various sorts of strings at time of recall? And, if the former, are they due to differences in the initial comprehension of the strings, differences in memorial processes, or both? We shall now mention the results of some studies addressed to these questions. To make stimulus reconstruction by the subject unnecessary Slamecka (1969) used a recognition task for sentences, anomalous sentences, and word lists. Employing an analysis of the data based upon signal detection theory he obtained results similar to those of Marks & Miller. Of course this still leaves open the question of the locus of these retention effects. The fact that Miller & Isard (1963) had obtained similar sorts of results in an intelligibility task where subjects were required to shadow various sorts of strings in noise is, of itself, not conclusive in demonstrating that retention differences are due to

EFFECTS OF SOME SYNTACTIC VARIABLES

15

differences in understanding or initial acquisition because the shadowing task itself yields a 'production' measure and, more important, because it is not at all clear that such immediate repetition or shadowing requires full analysis or comprehension of the strings. There is a study relevant to this issue conducted by Wang (1970a). She wished to determine whether it was differences in the difficulty of comprehension that mediated the previously obtained differences in retention. The subjects were presented with strings of the four kinds employed by Marks & Miller, only involving more complex and varied source sentences, and were instructed to try to understand the meaning of each string "as they would an ordinary sentence" and then to rate the comprehensibility of each string on a 5-point scale. When the comprehension task was finished incidental learning of the strings was tested by performance on a recognition memory task. On the comprehensibility task the item types were arranged in the order: sentence, anagram, anomaly, word list. As Wang points out it is reasonable enough that sentences which satisfy both syntactic and semantic conditions be rated most comprehensible, and that word lists which satisfy neither condition be rated least comprehensible, and the difference between anagrams and anomalies may be taken as simply indicating the "primacy of semantic structure for comprehension". On the recognition task, performance was best for sentences and worst for word lists, with the other two item types falling intermediate, thus in general these results replicate the previously obtained results. However, while anagrams were rated significantly more comprehensible than anomalies they were recognized significantly worse, and there was only a very moderate relation (median r = .21) between comprehensibility ratings and recognition scores for the items. These results indicate that differences in retention cannot simply be attributed to differences in the initial comprehension of the items, and thus they raise problems as to unknown properties of the memorial system which might be responsible. Because there are data both with regard to initial comprehension and later (incidental) memory they at least permit us to raise the issue of the nature of possible memory effects. This of course is subject to a

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EFFECTS OF SOME SYNTACTIC VARIABLES

caveat about the technique used to assess comprehension, which required subjects only to rate their degree of comprehension of each item, without providing any further evidence about the nature or extent or correctness of that comprehension; thus the technique depends critically on the ability of the subject to monitor his own comprehension processes. There is evidence however (see e.g. Schwartz, Sparkman & Deese, 1970; Wang, 1970b) that such ratings can be made in a reliable and valid way, being sensitive to differences in the grammatical complexity of sentences, even in circumstances which preclude any complete analysis because of the speed with which items are presented and judgments made. The studies reviewed so far while they have attempted to distinguish between syntactic and semantic sources of sentence malformation have otherwise been quite unanalytic. Obviously there are different ways in which a sentence may be syntactically defective and some malformations may be more serious and therefore perhaps more consequential for performance than others. Let us now consider two studies which did approach this problem in a more analytic fashion, studies which made use of sentences involving known rule violations varying in generality and ordering of the rules violated. Downey & Hakes (1968) constructed normal sentences and sentences embodying three types of rule violations varying in generality from (a) violation of phrase-structure rules, through (b) violation of strict subcategorization rules, through (c) violation of selection restrictions. These types of violation are strictly ordered in that violating a phrase structure rule renders the subsequent subcategorization rules and selection restrictions irrelevant, and violating a subcategorization rule renders the subsequent selection restrictions irrelevant. Downey & Hakes had subjects rate the acceptability of these sentences and paraphrase them, and had another set of subjects learn them, with free recall required after each of the five learning trials. The acceptability ratings fell as predicted in the order: sentence, selection restriction violation, subcategorization violation, phrase structure violation. The free recall data, however, are rather different. While the sentences were learned most rapidly and the strings with phrase

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17

structure violations most slowly, the strings with violations of subcategorization rules were learned more readily than those with violations in selection restrictions. Given such results one has a choice of (1) accepting the rating data as representing differences in the comprehensibility of the various sorts of semi-sentences and concluding that the free recall results cannot be attributed to differences in initial comprehension but must be due to some systematic biases introduced by the memory systems, or (2) of challenging or rejecting the rating task as really one requiring the interpretation of the strings presented, in which case a simple relation between comprehension and retention might still obtain. In terms of some of their paraphrase results Downey & Hakes opt for the latter alternative. We shall not pursue this matter here since, of course, there is still another possibility, namely that the results obtained may not be replicable, that there may in fact be a simple relation between rating and memory data, as suggested by the findings of Stolz (1969) to be discussed immediately. In a study of 'queer' sentences Stolz employed (among other types of items) well formed sentences, sentences with selection restriction violations, sentences with subcategorization violations and sentence anagrams, with the items involving selection restriction violations being of two kinds: those involving violations with regard to the feature human, and those involving all other sorts of features (which are higher in a feature hierarchy and therefore characteristically more general). He had subjects rate these items for acceptability, considering the ratings as providing some "sort of global index of the cognitive irregularity" of the sentences, and also obtained data on a short term memory task involving Savin's (1965) Archimedean technique, and in a free recall task of the sort used in previously described studies. On the rating task the order of sentence types was: normal sentence, violation of selection restriction with regard to human feature, violation of selection restriction with regard to other features, violation of subcategorization rules, sentence anagrams (with almost all the differences between sentence types highly significant). The short term memory task employed is one where one tries to gauge the memory space needed for a sentence

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EFFECTS OF SOME SYNTACTIC VARIABLES

or string by noting how much irrelevant material can be remembered along with it. On this task the order of performance for the various item types considered here was exactly the same as that on the acceptability rating task, and the same is true if one considers the proportions of correct recall in the long term memory task. It should be pointed out, however, that on the memory tasks some of the differences between sentence types were quite small, and far from significant. Nevertheless, the over-all general agreement between the results of the rating task and those of the two memory tasks is quite impressive, and the lack of interaction between type of rule violation and performance in the short term and longer term memory tasks certainly provides some warrant for Stolz's conclusion that "linguistic rule violations primarily impair the comprehension phase rather than the perceptual, storage, or subsequent retrieval phases". Essentially he is arguing, for the case of semi-sentences, that to the degree anything makes it difficult to produce an acceptable semantic reading for a string this will uniformly impair all further or subsequent processing. Taken at face value his results are indeed consistent with this conclusion. But there is some question as to whether the results should be taken at face value. Thus the acceptability ratings may well be tapping something quite distinct from the comprehensibility or intelligibility of the sentences, since e.g. sentence anagrams which are very unacceptable as sentences may actually be quite intelligible, see the results of Wang (1970a) where this is exactly what was found, and difficulty in recalling such sentences, say on a long term memory task, may be due to difficulty in reconstructing them in their particular distorted form. Further, as we shall see presently, there are strong grounds for questioning the data yielded by Savin's Archimedean technique as really revealing of immediate memory storage requirements. In addition there is evidence, of the sort cited by Danks (1969) in the context of a study of the comprehension of deviant sentences, that variables such as interword associations and word frequency which can have substantial effects in a learning task may only account "for a minimal proportion of the variability in sentence comprehension". Thus, at most, Stolz's data can only

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be regarded as suggestive. In any case it must be obvious that even if comprehension and memorial performance stood in a simple relation for the case of syntactically malformed strings or semi-sentences, where one could perhaps argue that the listener was never able to get a proper semantic reading in the first instance and therefore had to burden his memory with a very queer sort of object, this would not necessarily require a similar relation between comprehension and retention for the case of well formed sentences where the listener can achieve an adequate interpretation or reading, and where there then arise questions as to the properties of this well formed reading as an object for memory, and with regard to the operation of memorial processes on such properties. Therefore we now turn to a consideration of memorial performance for the case of various sorts of syntactically well formed structures.

2.2 L E A R N I N G A N D M E M O R Y F O R WELL F O R M E D SENTENCES 2 . 2 1 THE ROLE OF SURFACE STRUCTURE

There is considerable evidence that phrase structure properties may be important in the learning and recall of sentences (see e.g. Bever, 1968a). For example, Anglin & Miller (1968) had subjects memorize prose passages presented in segments that conformed to the phrase structure of the sentences, and in segments which violated that structure, and on a free recall task found that performance was significantly better in the former case. They interpret this as an initial processing effect, arguing that subjects must do additional work to grasp the grammatical structure of the sentences when the grammatical units "are fragmented by a nonphrase type of segmentation", and that this is what makes it more difficult to memorize the materials. As another example consider one of the many studies conducted by Johnson (1965). This study was cast in a paired associates format with subjects required to learn sentences

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in response to digits as stimuli. Arguing that "grammar provides subjects with a ready-made and reliable recoding scheme" Johnson assumed that subjects would learn the sentences in terms of phrase-size chunks. Responses were scored for "the conditional probability that the words in the sentences were wrong given the immediately preceding word was right" and Johnson found that the conditional or transition error probabilities (TEPs) were not equal from word to word but that TEPs rose significantly at phrase-structure boundaries, i.e. that such conditional error probabilities are larger between than within constituents, suggesting that sentences may be learned and remembered in terms of phrase length units. Note that again the emphasis is on the role of surface structure properties in the initial encoding of the materials for learning. Note further that in the cases cited, and for others that might have been cited, surface structure effects are confounded with possible deep structure effects. Thus in the Anglin & Miller study the segmentation that violated the phrase structure of the sentences also characteristically impaired or destroyed underlying or deep structure units, and in Johnson's study a substantial elevation in TEPs between major surface structure phrases falls also at the break between subject and predicate in the deep structure. While it appears clear that the major impetus to experimental work has come from analyses due to transformational grammar, there has also been some work influenced by Yngve's formulations (1960) that has sought to account for findings in terms of surface or phrase structure properties only, albeit in terms of a particular sort of theory regarding the role of these in speech. Yngve's theory is a model of language production where the constituent structure tree is built from the top down and from left to right, under constraints of limited short term memory, which temporary storage capacity is or may be strained by 'regressive' left branching structures. Yngve stresses that the maximum allowable depth of a sentence is constrained by memory limitations on the part of the speaker. In some general respects Yngve's account would appear to be implausible as a psycholinguistic model, for it requires that performance proceeds from the top down as though a speaker first decides on the

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structure of a sentence before choosing what he is going to say, and as though "a hearer does not begin to process a sentence until after he hears it in its entirety", as well as entailing an asymmetry between a model for the speaker and one for the listener. More particularly, there are a number of difficulties with regard to the ways in which this approach or model has been adapted by psychologists such as Martin & Roberts (1966). First, the model as originally conceived was one for the speaker, while it has been adapted or employed as a model for the listener, and as has been pointed out by a number of people (see e.g. Rohrman, 1968) it is not at all clear that this can be plausibly done. The suggestion is that as the listener hears a sentence in addition to perceiving each word he makes "an encoding response a major constituent of which is the formation of an expectation of what is coming next — and that these responses are a major component of what is placed in memory store". Given the varied possibilities of the language such expectations may be insufficiently constraining and informative for the listener since "sentences can contain an indefinite amount of structure which in general cannot be anticipated" (Perfetti, 1969b). Second the model was one that characterized the short term memory constraints on the speaker and it has been transposed or applied as though it dealt with long term memory constraints operative for the listener. This would make sense only if one assumes that all effects are ones depending on the initial encoding of the sentence by the listener, i.e. as comprehension effects, or perhaps if one were to consider the subject who is the listener as a speaker at time of recall or retrieval. Finally, Yngve was concerned with the way in which maximum depth might exceed the temporary storage capacity of the speaker, as it were one might forget where one is in a sentence and therefore be unable to continue properly, while experimenters (with but a single exception which yielded negative results for the depth hypothesis, see Perfetti & Goodman, 1971) have always used mean phrase structure depth — average number of left branches per word — as a measure of structural complexity, and it is not at all clear that this is an appropriate embodiment of Yngve's model, that mean depth even

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if in some sense a measure of surface structure complexity is really relevant to problems of constraint on memory of a listener, whether short term or long term. Given these problems it may not be surprising to find that the results for learning and memory studies using the mean depth measure are mixed, at the very best. Thus Martin & Roberts (1966) in a study in which they independently manipulated mean depth and sentence kind (kernel, passive, negative, negative passive, etc.) found that differences in mean depth were significantly related to differences in free recall of the sentences, sentence kind was also significant (as was the interaction between the two factors). Because ease of recall for different sentence kinds did not at all correspond to the order predicted by a transformational grammar they conclude that when sentence kind is controlled mean depth is the crucial factor. However, as pointed out most cogently by Rohrman (1968), the study failed in its attempt to vary orthogonally surface structure (depth) and deep structure (transformational complexity), for while sentences were equated in terms of passive and negative constructions they were not equated in many other transformational respects. To keep sentences of equal length Martin & Roberts inserted modifiers which minimally affect surface structure, but which considerably complicate deep structure. Hence "in trying to manipulate surface structure complexity they systematically changed the deep structure" confounding the results, and making them "totally equivocal with respect to the relative power of surface and deep structure". In a further study (Martin & Roberts, 1967) recall was found to be unrelated to mean depth. Martin, Roberts, and Collins (1968) investigated depth in the context of a short-term memory study as opposed to the longer term free recall task of the studies just mentioned. While the depth effect was significant, so was the interaction between depth and sentence kind which they considered to be the more important effect. Analyzing the results in considerable detail they came to the conclusion "that in processing sentential messages the subjects focus on key elements, to the detriment of other, sometimes informative elements, and generate in recall an essentially 'new' sentence based on the elements

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retained". This may well be the case, but this is certainly a very far cry from an analysis in terms of Yngve's model or any recognizable offspring of that model. Indeed such an analysis which suggests that a sentence may be stored in terms of its underlying semantics and then reconstructed at time of recall from the surviving semantic properties is one that we shall argue for later. One might mention that Wright (1969) using Savin's Archimedean technique found little unequivocal support for the depth hypothesis. Perfetti (1969a) found no support for the depth hypothesis in two studies where subjects were required to recall individual sentences after a ten second interval filled with mental arithmetic; in some further studies (Perfetti, 1969b) mean depth again failed to have any significant effect on retention. Bearing in mind some of the problems with the depth hypothesis noted above (for some additional difficulties see e.g. Perfetti, 1969b) the lack of convincing support is perhaps not surprising. It should be stressed that the data surveyed so far do not demonstrate that, in principle, any account phrased in surface structure terms is, or must be, inadequate, only that a particular account or rather a particular version of such an account does not bear up well in the light of experimental evidence. Given some of the general difficulties with the depth hypothesis it is rather surprising that it has engendered as much experimental interest as it has. Perhaps the possibility of easily deriving some complexity metric for sentences was seductive since it appeared to offer a ready, linguistically derived and psychologically relevant solution to a crucial and hitherto intractable problem. 2 . 2 2 THE ROLE OF DEEP STRUCTURE

Mehler (1963), following Miller (1962), suggested that a sentence is processed by transformationally recovering its deep structure and argued that in a recall task the subject should store the deep structure of a sentence ("the underlying kernel") plus some "mental tags" or "footnotes" indicating the transformations to be applied to the underlying form at time of recall, with the deep structure

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information and the footnote information stored relatively independently of each other. He tested this hypothesis using a rote learning and prompted recall task where subjects were required to learn a set of eight sentences consisting of a simple, active, affirmative declarative (SAAD), a passive (P), a negative (N), a question (Q), plus all possible combinations of these. His hypothesis predicts that the SAAD or 'kernel' sentences would be learned most easily, that difficulty of the other sentences would be a function of the number of transformational tags, that syntactic errors would be more likely to involve single than multiple changes in transformational tags, and that errors would tend to omit transformations and thus regress or be closer to the 'kernel' forms. While on the whole consistent with the predictions, there are a number of questions that may be raised concerning the interpretation of Mehler's results. First, if deep structure includes elements representing negation, interrogation, and passivization, in line with developments in transformational grammar subsequent to the early 1957 formulation of Syntactic Structures, then as Wanner puts it "any evidence for these 'footnotes' is ipso facto only evidence that these aspects of deep structure are components of the memory trace". There is no need to assume that a full transformational history is also stored, and "the psychological operations which recover the deep structure of a sentence may be unrelated to the transformational cycle". Further, if the trace does reflect deep structure properties why should memory be biased for one aspect of deep structure (propositional content) and not another (whatever corresponds to the marking for negation, interrogation, passivization)? Actually the tendency to make errors in the direction of the 'kernel' appears principally due to a response bias in favor of SAAD sentences, and this response bias might well be due to the disproportionate use of SAAD sentences in every day speech (for statistics on the normal overwhelming preponderance of SAAD sentences see Goldman-Eisler & Cohen, 1970); for other possible interpretations of the effect in terms of the particular properties of the learning situation employed see Wanner (1968). One should point out too that, with one exception the case of affirmative and

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negative questions, Mehler systematically ignored the possible role of semantic factors in determining similarity among sentences, and that possible semantic and syntactic effects are partially confounded. A priori it seems quite implausible, for example, that a syntactic simplification which is radically meaning changing such as the dropping of the negative transformation should occur with any frequency, given the usually good memory for the gist of a message or sentence. Indeed a re-analysis of Mehler's data shows that when errors involving one-step transformation changes are considered, in seven out of eight comparisons meaning-preserving errors are on the average more common than meaning-changing ones. All this is not to say that Mehler is necessarily wrong in his interpretation, only that data of the sort he obtained do not unequivocally require such an interpretation. Psychologists have been interested in assessing the similarity relationships that obtain among related sentence constructions through the study of errors or confusions because of the hope that such data might indicate something as to the similarity among underlying representations and thus, indirectly, as to the nature of these representations. One excellent study which typifies this logic is that by Clifton & Odom (1966). They carried out a series of experiments investigating the similarity among sentences of the same eight types as those studied by Mehler. The main technique employed involved the examination of confusions among these sentence constructions on a recognition task. The situation was one where the subject was shown a list of sentences a few times and then shown a longer list "including sentences transformationally related to those on the first list" with instructions to signal every old sentence, i.e. every sentence that had appeared in the first list. The confusion matrix generated by the various kinds of false recognitions was analyzed principally by means of a nonmetric multidimensional scaling procedure which yields a dimensional representation of the distances among the various sentence constructions. Much the same pattern of structural relationships was found in all the studies, and also upon a re-analysis of Mehler's data. The findings in each case could be represented very adequately by a prism whose base

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is defined by SAAD, P, N, and PN all substantially separated, and whose top surface is defined by Q and NQ, and PQ and PNQ, with the members of each of these pairs very close together, and the pairs themselves midway between the affirmative and negative non-questions. The constructions fall into a pattern very consistent with that implied by a grammatical analysis due to Katz & Postal (1964) in which differences among the constructions are ascribed to differences in deep structure elements. The authors conclude that "these results indicate a powerful and consistent effect of grammatical relationships among sentences on their perceived similarity" (my italics), that the results support the hypothesis that sentences may actually be held in mind in a way consistent with a particular grammatical account of their structure. In an important sense such a conclusion is obviously not warranted since the data concern confusions on a memorial task "simultaneously providing information (a) regarding the possible cognitive representation of certain structures (or better the similarity between such representations) and (b) about possible memorial and retrieval effects" (Fillenbaum, 1970), and we have no way of factoring this information into its component sources. Let us consider one aspect of these results more fully in the light of some subsequent work. With regard to the distance between Q and NQ, and PQ and PNQ respectively, the results were clear and very similar in all experiments: these pairs of points fell very close to each other, and were much closer to each other than to any other points. Clifton & Odom interpret these results as corroborating the Katz & Postal analysis, that is, as evidence for the structural similarity or even identity of affirmative and negative questions. Actually, even taken at face value, these results can only indicate that certain structures (e.g. Q and NQ) are more similar to each other than are other structures (e.g. Q and N), without being strong evidence for the essential identity of the former structures, since what we are dealing with are relative distances. To determine whether affirmative and negative questions really do have the same underlying representation, one needs to determine as directly and fully as possible the ways in which they are under-

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stood. Fillenbaum (1970) attempted to assess such understanding by use of three different, relatively direct procedures: (a) paraphrase, (b) equivalence judgments, and (c) prediction of speaker expectations. In the first task the subject must rephrase each sentence in his own words while conserving meaning, in the second task he must judge whether or not two sentences are equivalent in meaning, and in the third task he must guess as to the answer expected by someone who poses a Yes/No question in a particular way. All of these are tasks which constrain the subject to analyze carefully the sentences with which he is presented and to attend to fine distinctions in meaning, something which is not required and may not happen at all when memorial tasks are used. The results can be summarized very readily: on all these direct tasks there were substantial differences between the affirmative and negative question constructions (which had appeared to be so similar in terms of the indirect data yielded by the memorial tasks). In the paper in which these results were presented the main methodological conclusion drawn was that one could not simply use the data yielded by memorial techniques as directly revealing of underlying syntactic structures. Here it might be appropriate to stress a somewhat different, if complementary point. Namely that if one considers the data yielded by the direct procedures in conjunction with those yielded by the memorial task then this suggests something about what sort of information is lost in memory, and might thus generate some speculations about the nature of memorial or retrieval processes. While in principle this argument is correct, it is subject to the proviso that the sort of information that the subject can extract, as revealed by the tasks used to examine understanding, was actually extracted in his initial processing of the sentences in the memorial task. If this is not the case, and we have no strong warrant for believing that it is, given the way the memorial tasks were and are usually posed, then there is hardly much point to speculating about how information was lost in long term memory, for it may not have been entered there in the first place. The experiments we have just been discussing involved longer term memory in tasks where whole lists of sentences had to be

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learned and remembered, tasks in which there might result all sorts of unspecifiable interference effects among sentences. It would obviously be desirable to investigate these sorts of problems in a short term memory situation in which the subject had to cope with only one sentence at a time. This way done by Savin & Perchonock (1965) in an experiment designed to demonstrate that transformations are encoded in immediate memory apart from one another and from the rest of the sentence, and to measure the amount of immediate memory occupied by several grammatical features. Assuming that immediate memory has a small fixed capacity, and that sentences are stored in terms of their deep structure, they suggested that the amount of memory space needed for a sentence could be measured by use of an Archimedean technique which notes how much irrelevant material could be remembered along with that sentence. By using sentences of different structure one could thus determine the amount of immediate memory occupied by different grammatical features such as negative, passive, question, negative-question, emphatic and w/j-transformations, on the assumption, noted above, that each of these features is encoded separately, and takes up a characteristic amount of space in immediate memory. The subject was always presented with a sentence followed after 5 seconds by a list of eight unrelated words, and was required to recall first the sentence and then as many of the words as he could. The results were very clear-cut: not only were fewer words remembered for sentences requiring more transformations, but the data had strong interval properties, permitting one to make consistent estimates of the amount of memory space taken up by each of the transformations. While for most of the sentence types employed grammatical complexity and sentence length are confounded, in two cases, emphatic affirmatives and wA-questions, added complexity does not result in increased sentence length, and, nevertheless, both of these transformations increased the difficulty of remembering sentences. Unfortunately it does not appear to be the case that analogous results obtain when this Archimedean technique is extended to the study of other syntactic relations (see Fodor & Garrett, 1966), it is not at all clear whether these results

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hold up even for the present case, i.e. affirmatives, negatives, passives, questions and emphatics, or whether they require the sort of interpretation advanced by Savin & Perchonock. Matthews (1968) replicated and extended their study but did not find any clear effect of syntactic form upon recall of unrelated words. Glucksberg & Danks (1969) found only weak effects of transformational complexity on word recall, and argued that these effects might well be attributable to differential word delay since the more complex the sentence the longer it tends to take to say it, and therefore the longer the delay between word presentation and recall. Word recall in their study was found to be significantly related to delay-in-wordrecall, as was the case in Matthews' study, where delay in word recall had been directly manipulated. As Glucksberg & Danks suggest, "forgetting as a simple function of time" may provide the most parsimonious explanation for the data. Finally, Epstein (1969) replicated the Savin & Perchonock study using two recall conditions — "sentence then words" or "words then sentence", with the cue as to which recall order was required coming after the last member of the list of words had been presented. With list words recalled second, as in the original study, Epstein obtained roughly the same results. However, when list words were recalled first these effects were almost completely eliminated. This suggests that differences in word recall may perhaps be due to interference from prior recall of the sentences, but in any case the results tell strongly against the original Savin & Perchonock formulation, which must surely require that there be no systematic differences in the results as a function of the order of recall of sentence and words, since it is an hypothesis regarding the initial encoding and storage of sentence materials. It should be pointed out that, taken in conjunction, the original results plus the results of the later experiments, particularly that of Epstein, do have something to say regarding recall or retrieval processes, but the question is whether this is in any sense linguistically relevant or in any sense implicates syntactic factors in short term memory, or whether it merely indicates that for the case of sentences, as indifferently for almost anything else, there may be retrieval or output interference effects, and the passage of

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time may degrade recall. One of the major themes of this essay has been that while many studies have ostensibly been studies of the memorial effects of syntactic factors, in fact the use of memorial techniques has generally been quite incidental, and the real concern has been with what gets entered as the object for memory, not with what happens to that object. This may be seen quite clearly in some studies apparently on the importance of deep structure properties in sentence memory, studies more particularly on the deep structure role of a word as determining its effectiveness as a prompt for recall (Blumenthal, 1967; Blumenthal & Boakes, 1967). While Blumenthal begins his first paper by saying that the purpose of the investigation "was to test for some memory effects of certain basic features of grammar" he stresses elsewhere (in Lyons & Wales, 1966) that these memory experiments "were intended as a competence study in that their purpose was to show experimental verification of the competence model; use of the memory modality was incidental" (my italics). In these studies Blumenthal asked subjects to commit a set of sentences to memory, and then had them attempt to recall the sentences, each sentence now prompted by a single word. In the first study the sentences all had the same surface structure, but differed in deep structure in that some of the sentences were standard passives (e.g. 'Gloves were made by tailors') while others consisted of passives with the agent ¿j-phrase replaced with a non-agent ¿»j-phrase ('Gloves were made by hand') such that the final nouns in the former case functioned as logical subjects, but in the latter served only as adverbials. It was found that nouns in the former case involving the more inclusive subjectof-sentence relation were significantly more effective prompts than the modifier nouns in the latter case. In the second study (Blumenthal & Boakes, 1967), distinguished for the care taken to ensure full initial understanding of the sentences involved, it was found that for sentences matched in terms of surface structure, a noun prompt that was the logical or underlying subject of the sentence facilitated recall more than a noun prompt which was the logical object, and that sentence modifiers were better prompts than noun

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modifiers. Thus given sentences of the form A: 'John is eager to please', and B: 'John is easy to please', the initial noun was a significantly more effective prompt in A than in B, and the adjective in B was a significantly more effective prompt than that in A, where prompt effectiveness is now defined in terms of the improvement in performance in prompted recall over that in free recall. Thus in both studies recall differences corresponded to the nature of the underlying relations among sentence parts, and the deep structure role of a word appeared to govern that word's effectiveness as a prompt, the more generally related a word to other words in the underlying syntactic organization of the sentence the more effectively it served to prompt retrieval of the rest of the sentence. It should be noted (see Wanner, 1968) that such results, which indicate that the more inclusive the grammatical relations involved the more effective the prompt, are direct evidence with regard to the psychological relevance of deep structure, as claimed by Blumenthal, only if the relation between deep structure and the basic grammatical relation is one of identity, but that it is in fact "quite possible to suppose that assigning the deep phrase marker is not the means by which the basic grammatical relations are determined" since deep structure displays many features irrelevant to the grammatical relations. Levelt & Bonarius (1968) take issue with Blumenthal on two general counts, one methodological and one theoretical. As to methodology, they argue that the use of different sentences to realize the various independent conditions in Blumenthal's experiments may result in some unknown artifacts as a function of some properties of the particular sentences used, and that it would be preferable to use sets of homonymous sentences which are deep structure ambiguous. Thus, with appropriate antecedent context, 'John was found by the dog' may be understood as either a normal passive or as an agentless passive, referring say to the fact that John's body was found next to that of the dog. As to theory, in place of Blumenthal's formulation which stresses that the effectiveness of the prompt word is a function of its place in the underlying structure of the sentence they offer what they call the deep structure

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clue theory, i.e. the hypothesis that subjects use "surface markers (clues) to determine underlying structure" directly, arguing that prompt effectiveness is determined by the deep structure information carried in the prompt word. As they note this is essentially the position taken recently by Fodor and his associates (see e.g. Fodor, 1971; Fodor & Garrett, 1968). Indeed, capitalizing on the possibilities inherent in cross-linguistic studies, the stated aim of their work is to "investigate the role of suffixes as possible guides to deep structure". Their research was carried out in Dutch and Finnish, the latter an agglutinative language which provides an abundance of underlying syntactical information in the suffix structure of the sentences, information which could allow the listener or subject to distinguish between different possible deep structures. Given sentences of the form 'The shop-girl is too ugly to seduce', whose translation equivalents in Dutch and Finnish can be understood as either 'The shop-girl is too ugly to seduce (anyone)' or as 'The shop-girl is too ugly (for anybody) to seduce', Levelt & Bonarius provided appropriate antecedent contexts at time of initial presentation to cue one meaning or the other. Then they carried out a study of prompted recall following a procedure similar to that used by Blumenthal. On Blumenthal's hypothesis the prompt phrase 'the shop-girl' should presumably be more effective if the shop-girl is understood to be the one who is doing the seducing, than if she is considered to be the object of the seduction, on the deep structure clue theory no difference is to be expected (and there should be no difference between Dutch and Finnish since the manifest form of 'shop-girl' is the same in each case for both possible underlying structures). On the other hand, in terms of the deep structure clue theory, but not in terms of Blumenthal's formulation, there should be a difference between Dutch and Finnish in the prompt effectiveness of the verb corresponding to 'seduce'. In Dutch precisely the same surface form occurs regardless of which sense of the sentence is involved, whereas in Finnish the surface form of the verb is very different depending on the sense intended. Examination of the results indicates that in both Dutch and Finnish 'The shop-girl' was equally effective as a prompt

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"independent of its deep structure role (subject or object) in the sentence". This evidence is of course inconsistent with Blumenthal's hypothesis. While the verb corresponding to 'seduce' was in fact a more effective prompt in Finnish than in Dutch, the differences were slight and far from significant. Some further results were such as to be inconsistent both with Blumenthal's hypothesis and the deep structure clue theory. Levelt & Bonarius conclude by suggesting that properties of the "semantic meaning of the prompt word" may be important factors in the recall results, without indicating how this may work. For our purpose these results should have some cautionary value, both in that they fail to replicate those of Blumenthal and thus raise some questions about his hypothesis, and in that they give only the most meager support to the deep structure clue theory which is very close kin indeed to the position espoused by Fodor and his associates. As we have pointed out above, Blumenthal argues that his results demonstrate that the underlying grammatical relations holding between a prompt word and its source sentence determine the ease of sentence recall, with recall better the more inclusive the grammatical relations that obtain. Thus e.g. subject nouns are better prompts than modifier or object nouns because the subject-of-sentence relation is the more inclusive one encompassing most of the sentence. Another possibility is that for sentences with more than one underlying proposition a prompt word is effective as a function of the number of underlying propositions in which it figures. As Wanner (1968) puts it "if the deep proposition is the mnemonic unit then conceivably the number of deep propositions in which a prompt word is involved enumerates the set of entry points available for successful retrieval of the sentence". Since the "atomic sentences defined by the base component of the grammar display considerably more information than the listeners would minimally require in order to determine the grammatically relevant grammatical relations. . . there is nothing necessary about the claim that deep propositions are determined during comprehension", and evidence that deep propositions are mnemonically relevant would thus be of some significance in that it is consistent with a sub-

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stantive hypothesis about comprehension, and thus poses problems for any "theory of comprehension which claims that deep propositions are not realized in the course of understanding a sentence". Here then we have a case where, with more justification than usual, information about memory for an object will be taken as revealing about the nature of the object memorized. In many instances the relational inclusiveness hypothesis and the deep proposition hypothesis will lead to similar predictions. Thus if one finds that 'John' is a better prompt for a sentence such as 'John is eager to please' than for a sentence such as 'John is easy to please' one can argue, with Blumenthal, that this is to because in the first but not the second instance 'John' enters into the more inclusive subject-of-sentence relation. Or one can note, with Wanner, that 'John' is involved in one more deep proposition in the 'eager' sentence than in the 'easy' sentence, and suggest that this is what may be responsible for the results. The two hypotheses need not always lead to the same prediction, however. Thus the fact that an adjective serving as a sentence modifier, as 'easy' above, is a more effective prompt than one serving as a noun modifier, as 'eager' above, is consistent with the relational inclusiveness hypothesis but cannot be explained in terms of the deep proposition hypothesis, since both types of adjectives are involved in only one underlying proposition. On the basis of a variety of evidence Wanner shows that the superiority of 'easy' over 'eager' adjectives as prompts may be based on semantic and pragmatic factors and may be entirely unrelated to their syntactic function, which leaves us with no basis to choose between the hypothesis. Wanner attempted to contrive a test case which might permit such a choice by constructing sentences where a prompt word varies in propositional involvement but not in relational inclusiveness. Sentences were constructed according to the format 'The governor asked the drinking'. Here 'detective' is a constituent detective to cease prevent of three deep structure propositions in the case of 'The governor asked the detective to cease drinking' but is a constituent of only two deep structure propositions in 'The governor asked the

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detective to prevent drinking'. On the other hand, the relation of 'detective' to the predicate string 'asked.. . to cease drinking' is the same as that to the predicate string 'asked. . . to prevent drinking' so that there is no difference in relational inclusiveness between the two cases. Note, further, that the deep proposition hypothesis predicts that in both 'cease' and 'prevent' sentences 'detective' should be a better prompt than 'governor' since the former word is involved in either three or two deep propositions, while 'governor' is never involved in more than one. Just the opposite prediction must be made from the relational inclusiveness hypothesis since 'governor' is the subject of the highest sentence in the phrase marker and is directly related to the rest of the sentence, while 'detective' is only the object of the highest sentence and therefore has no direct relation to the subject, 'governor'. Groups of subjects were exposed to ten sentences with 'cease' type verbs and ten with 'prevent' type verbs, half of the groups received 'detective' type prompts, half 'governor' type prompts. Eight groups of subjects were actually run in order to control for various confounding possibilities, e.g. to control for any possible topic/comment effect of the 'detective' and 'governor' prompts half the groups had the sentences in passive versions, such as 'The detective was ordered by the governor to

cease prevent

drink-

ing' and half in the active version already mentioned. The experiment was run and, with some changes and improvements in the definition of the prompt effectiveness scores, the data analyzed in the manner of Blumenthal & Boakes. The results tell against the relational inclusiveness hypothesis since control or 'governor' prompts failed to be more effective than the experimental or 'detective' prompts. On the whole the results support the deep proposition or propositional involvement hypothesis, indicating that the greater the number of underlying propositions per prompt word the more effective the prompt, thus e.g. 'detective' is a better prompt in 'cease' sentences than in 'prevent' sentences. While not overwhelmingly strong in statistical terms the overall pattern of results is consistent with the propositional involvement hypothesis

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suggesting "that the nuclear sentences specified by the deep phrase marker constitute basic mnemonic units". 1 But why should deep propositions rather than grammatical relations be retained in memory, even though the listener must be able to recover the latter in order to understand a sentence in the first place? If the long term representation of a sentence is 'semantic in content and abstract in nature', then there is no need for that semantic content also to maintain the original grammatical relations (although of course it may do so). Semantic relations may be maintained in paraphrases that reverse the underlying grammatical relations of the original sentence, thus 'John sold the book to Mary' and 'Mary bought the book from John' are semantically equivalent even though the grammatical relations into which the terms 'John' and 'Mary' enter are quite different in the two sentences. There is evidence, see e.g. a study by Fillenbaum (1968) on the learning of 'converses', which indicates that during learning confusions between such pairs of sentences are particularly common. What this suggests is that "a memory system which retains just the semantic content of a message need not include any information concerning the basic grammatical relations which were involved in determining that content". We shall return to this issue more generally later on, when we shall attempt to provide some additional evidence in support of the claim that sentence memory is semantically based. Here, following Wanner, we shall add only the suggestion that deep propositions may be retained in memory just because such propositions do have a direct semantic effect in that they may define the scope of selectional dependencies. A series of studies by Rohrman on the role of deep structure properties in the recall of nominalizations illustrates in miniature how research on syntactic factors in memory develops, and the 1

There are some recent results due to Lesgold (1972), who studied pronominalization as a device for unifying sentences in memory, which indicate that prompt words may not be successful just in proportion to the number of underlying propositions in which they figure, that certain properties of sentence structure such as pronominal reference may serve to unify linguistic inputs and thus systematically influence prompt effectiveness.

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sorts of problems of interpretation that often arise. Initially (1968) Rohrman sought to provide a clear test of the relative power of surface and deep structure accounts by pitting these against each other in a situation where subjects were presented with lists comprised of two sorts of sentences, and then tested in a free recall situation. The sentences were of two kinds: A sentences including object nominalizations ('They are digging holes') and B sentences including subject nominalizations ('They are growling lions'). In terms of an Yngve surface structure characterization the B sentences are slightly simpler, while in terms of a deep structure account the B sentences have a more complicated structure involving recursion and embedding (of the form 'they are lions — lions growl'). The results indicated that performance for the B sentences was significantly better, suggesting that surface structure properties might be the more important ones in governing recall. However, given that all the sentences begin with 'They are' it is more than possible that subjects were really only dealing with the remaining participle-noun segments, in which case they would be memorizing nominalizations only. So Rohrman repeated the experiment using just the last two words, i.e. the participle-noun fragments. The results were exactly the same as before, with subject nominalizations recalled better than object ones. Now in terms of surface structure both of these kinds of nominalizations are identical, consisting of a participle plus noun dominated by a NP node. However their underlying structures differ considerably. The deep structure of the subject nominalization is something like 'lions growl' while that of the object nominalization has the form '(PRO(dig holes))', thus the deep structure of the object nominalization is more complex in that it involves an extra node and dummy element. In addition, there are diiferences in the transformational histories of the two kinds of nominalizations. The subject nominalization has a permutation transformation to reverse the order of elements, whereas the object nominalization undergoes a deletion transformation to eliminate the PRO form. Either of these differences, that in number of nodes or that in transformational history might be responsible for differences in recall. Having re-

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peated and extended his nominalization study (including some additional controls) and having again found that subject nominalizations involving the simpler deep structure were better recalled than object nominalizations of more complex deep structure, Rohrman conducted a final experiment to determine whether deep structure complexity or transformational history was the (more) important determinant of the results. This experiment involved nominalizations equivalent in deep structure complexity but differing in their transformational histories. The same object nominalizations as before were used but now subject nominalizations such as 'boring lectures' which also involve a PRO form '(lectures (bore PRO))' were employed. Thus while deep structure complexity is equated there are differences in transformational history since the new subject nominalizations require both a permutation and deletion transformation, whereas the object nominalizations only require the latter. In this case no differences in recall were obtained, suggesting that differences in recall in all the experiments should be attributed to differences in deep structure complexity (differences in the number of deep structure nodes) rather than to the differences in the number or types of transformations involved in the derivations of the nominalizations from their deep structures. In addition (Rohrman & Polzella, 1968) it was found that nominalizations differing in deep structure complexity did not differ in verbal associative meaningfulness (i.e. in Noble's m measure, which indexes the ability to elicit free associates). So Rohrman was led to the conclusion that difficulty of recall of nominalizations is a function solely of deep structure complexity, and to the further suggestion that "difficulty of recall of any sentential material is a function of that same thing", that deep structure serves as the memory representation for sentences. Notice how we have gone from an initial confrontation between surface and deep structure hypotheses to a subsequent attempt to elucidate what it is about deep structure that is important, with results that suggest that deep structure complexity rather than transformational history may be the significant factor. In many ways this is similar to the sequence which has characterized the field as a whole.

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39

There is more to come, however. In a recent paper (Rohrman, 1970) it is pointed out that in subject nominalizations the verb is characteristically intransitive while in object nominalizations it is transitive, and that the noun in the former case is animate while in the latter case it is inanimate (compare 'growling lions' with 'digging holes' once more). Could it be that, nominalized or not, transitive verbs are more difficult to recall, and that inanimate nouns are more difficult to recall than animate ones? Testing memory for the nouns used in the earlier nominalizations in a free recall task of the sort employed previously, Rohrman found that animate nouns, those drawn from the subject nominalizations, were significantly better recalled than the inanimate nouns, stemming from the object nominalizations. Testing memory for the verbs phrased in the gerundive form (verb + ing), it was found that intransitives (stemming from subject nominalizations) were significantly better recalled than transitives (stemming from object nominalizations). This last result was again obtained, by Polzella & Rohrman (1970), with verbs now phrased in the infinitive form (and with some additional controls). While the results with regard to animate and inanimate nouns may not be crucial, see Rohrman's discussion on this point, those concerning the difference in memorability between transitive and intransitive verbs surely are of importance. Recall that in the original study (Rohrman, 1968) there was a difference in recall for subject nominalizations of the first sort and object nominalizations where intransitive and transitive verbs respectively occur ('growling lions' versus 'digging holes'), but no difference in recall for subject nominalizations of the second sort and object nominalizations where both verbs are transitive (e.g. 'contributing donors' versus 'contributing funds'). Thus, given that deep structure complexity and verb transitivity/ intransitivity are confounded, perhaps all we have is the finding that transitive verbs are more difficult to recall than intransitives, and any explanations of the results in terms of differences in underlying syntactic structure, "based exclusively on node-counting indices of syntacting complexity", can be called into question. Rohrman argues that perhaps the recall differences may be inter-

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preted in terms of differences in the lexical representations of the verbs, in line with some suggestions by Fodor, Garrett & Bever (1968) who on the basis of paraphrasing and anagram solution data speculate that "the exploration of the lexical analysis of the main verb of a sentence is a central heuristic in the strategy subjects use to recover its deep structure" (but see some cogent objections to this in Watt, 1970). Essentially, following Chomsky's 1965 analysis, Rohrman is suggesting that since the environment for transitive verbs (but not for intransitive verbs) is specified to include a noun phrase, there should be a very close relation between transitive verbs and nouns, which does not exist between intransitives and nouns. Consequently the subject may implicitly associate a noun object to transitive verbs "making a larger unit to store in memory and increasing the memory load". In fact, there is some evidence (Polzella & Rohrman, 1970) that transitive verbs elicit significantly more noun associations than do intransitive verbs, and that noun associations are made more rapidly to transitive than to intransitive verbs. However, while the above interpretation might perhaps be appropriate for the case of transitive and intransitive verbs presented in isolation, it is hard to see its relevance in the case of nominalizations, where a noun always comes supplied in the phrase. In any case perhaps the principal point to note is that there has been a shift in interpretation from one solely in terms of deep structure syntactic complexity to one in terms of possible differences in lexical representation, with regard to features or properties of the words (in particular the verbs) involved. Rohrman concludes (1970) that in any event recall appears to be influenced by some "very abstract information", that "all that is in dispute is what level of linguistic representation seems to be engaged" and that "the psychological utility and reality of linguistic constructs seem beyond doubt". At least with regard to the recall of nominalizations one may challenge all of these conclusions, particularly the last. This is exactly what Paivio (1971) has done. Paivio points out that a variable that "has proved to be very effective in various verbal learning and memory tasks is noun imagery, defined as the rated capacity of nouns to arouse sensory images"

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and raises the possibility that subject nominalizations may have exceeded object ones in imagery value, and that this may account for the better recall performance on the former than the latter, and that "If so, it may be possible to interpret the findings in terms of psychological processes without recourse to the linguistic concept of deep structure". Paivio obtained imagery ratings for the subject and object nominalizations that Rohrman had used originally and found indeed, that subject nominalizations had higher imagery ratings than did object nominalizations. To evaluate more directly the possible role of imagery and differences in imagery he repeated and extended Rohrman's experiment varying nominalization type and imagery level independently. Paivio found a highly significant imagery effect, with high imagery nominalizations consistently easier to recall, nominalization type had no main effect, and there was a significant interaction between the two variables which was relatively small, however, compared to the main effect of imagery. Paivio repeated the experiment twice with different lists of nominalizations and a modified procedure, and obtained essentially similar results. In each case there was a strong effect due to imagery, no overall effect due to nominalization type, and an interaction between imagery and nominalization type with the nature of this interaction effect varying inconsistently from experiment to experiment. This lack of any overall effect of nominalization type cannot be attributed to the fact that the subject nominalizations in these studies involved transitive verbs (as did the object nominalizations). Inspection of the nominalizations used by Paivio shows that quite a few of the subject nominalizations in his second and third experiments did appear to involve transitive verbs. However, there were few if any subject nominalizations involving transitive verbs in the first experiment, and yet the effect or rather the lack of effect, overall, with regard to nominalization type is the same in all three experiments.2 Why imagery differences should be so consequential 2 Although Paivio could hardly have anticipated the role that the contrast between transitive and intransitive verbs was to come to have in Rohrman's

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is of course an open question. In terms of some further correlational analysis of his data, indicating that noun imagery alone was the best predictor of nominalization recall, Paivio suggests that the subject need only recall "the referent object in order to reconstruct the 'scene' suggested by the nominalization as a whole, and then decode the latter into the appropriate verbal output". Whatever the plausibility of that particular suggestion, it is obvious that findings such as these of Paivio pose some very difficult problems for any attempt to explain the results for the recall of nominalizations in terms of properties of underlying syntactic structure, and equally for accounts in terms of differences in lexical representation of the verbs. Psychologists who have gone to linguistic theories for the source of their hypotheses need to show that such an approach will do a better job in accounting for the data than a very old fashioned formulation springing from within psychology of the sort offered by Paivio. If one does want to argue that semantic factors may play an important role here, one will need to spell out the relation between these and whatever is involved in the fact that some things are much more concrete and imaginable than others. 2.3 THE PROCESSING OF MULTIPLY SELF-EMBEDDED SENTENCES

Constructions involving relative clauses which make recursive selfembedding possible are of interest to the linguist since they demonstrate the inadequacy of finite state grammars and the need, at thinking, it is still rather puzzling that he should include among his subject nominalizations in the second and third experiments items (involving transitive verbs) such as 'frightening cliffs' or 'disgusting conditions' which have an underlying structure similar to that of 'boring lectures' which Rohrman had previously argued had as complex a deep representation as object nominalizations, and which Rohrman had demonstrated did not differ in recall difficulty from the latter. Obviously what is supposed to be critical here is not simply the difference between subject and object nominalizations qua subject and object nominalizations, but differences in the structures underlying various sorts of nominalizations.

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least, for phrase structure grammars. Constructions involving multiple self-embedding, as 'The nurse that the cook that the maid met saw heard the butler' are of interest to the psychologist because they indicate that sentences may be grammatically well formed and, nevertheless, psychologically or performatively unintelligible and impossible, constituting a case where grammatical sentences are completely unacceptable, which immediately raises all sorts of thorny questions as to how linguistic and psychological accounts are to be related. Further, that fact that multiply self-embedded sentences are particularly difficult to process, while related sentences including additional transformations may be much more manageable, is strong evidence that any theory which argues that degree of difficulty of processing a sentence is a simple function of its derivational complexity cannot be adequate in general. As in many other instances presented in this essay, difficulty of memorization has been used to index psychological complexity. But in the case of self-embedded or center-embedded sentences, more than in most other cases, workers have been quite clear and explicit in noting that what they were actually or principally interested in were comprehension effects or difficulties, and in conceding that ease of memorization could provide only the most indirect and limited measure of these. We shall begin by considering a study on the "free recall of self-embedded English sentences" (Miller & Isard, 1964), which was perhaps the first formal experiment conducted, and then examine some more analytic studies which seek to determine whether difficulties with such sentences are in fact attributable to comprehension effects, memory effects, or both, which seek to isolate some of the factors involved in the processing of such sentences, and which seek to identify more precisely the locus of the processing difficulties. In an early paper (1962) Miller pointed out that subjects had great difficulty in repeating back multiply self-embedded sentences and that such sentences were often repeated with list intonation, as though the listener had little or no idea as to what the sentence was about even when he was able to repeat correctly many of its words. Miller & Isard (1964) constructed different sentences con-

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taining exactly the same words but "re-arranged in different orders to give zero, one, two, three and four degrees of self-embedding". Subjects listened to a sentence and as soon as it was finished attempted to repeat it verbatim, this being done for five successive trials for each sentence. As predicted self-embedding made the sentences more difficult to remember. In general on every trial the number of errors increased as the degree of self-embedding increased. It appeared that no one had difficulty with single selfembedding, some had difficulty with two, and everyone had difficulty with three or more. Miller & Isard considered these results to be due to difficulty in comprehension of the more self-embedded sentences. As Miller put it, in Miller & McNeill (1969), "The source of the difficulty seemed to be the limited amount of immediate memory that was available for the cognitive task of unscrambling the syntax". More specifically Miller & Isard sought to interpret the results in terms of a "subroutine" hypothesis based on analogy to information processing by a computer system. They assume that subjects have command of a relative clause subroutine and that: ...when this subroutine is called the main sentence analyzing routine is interrupted, and the point at which it must be resumed is stored temporarily until the subroutine has been executed.... But now suppose that, while the subroutine is being executed a second such construction is encountered, so the subroutine is required to call itself. If this recursive feature were not available, confusion would result; the temporary memory for the point of re-entry into the main routine might be erased, so that when it is resumed the main routine would have to treat subsequent words as if they began a new constituent of the sentence. Essentially the suggestion is that people may have trouble with multiply self-embedded sentences because they do not have a 'push-down store' for remembering (many) re-entry points in their correct order. Thus not only is difficulty in sentence recall attributed to difficulties in initial sentence decoding, but more, if one takes the hypothesis seriously, one ought to be able to say where in the processing of such sentences difficulties should arise. Blumenthal (1966) and Stolz (1967) argue against the hypothesis

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that what happens is due to difficulties in retaining re-entry addresses in correct order, and suggest instead that multiply selfembedded sentences should be considered ungrammatical since subjects systematically misinterpret them. Blumenthal asked his subjects to re-write in more acceptable form each of a number of triply self-embedded sentences. Subjects had great difficulty in doing this properly i.e. in interpreting the grammatical subject of one clause appropriately as the object of its embedded clause. Characteristically subjects "either interpreted the sentences as having one relative clause containing a compound subject and a compound verb or they perceived three successive relative clauses, all referring to the initial noun", thus the sentences were generally perceived as though they were approximations to sentences containing one compound clause. Stolz asked his subjects to break each self-embedded sentence into its component clauses and to write down each clause as a single sentence. Subjects were given essentially unlimited time to perform this decoding task on doubly self-embedded sentences. Even under these circumstances only about half the subjects were able to successfully decode the selfembedded sentences in the absence of semantic constraints or support. In the presence of semantic constraints between subjectverb-object, performance was better, suggesting that subjects may make use of semantic clues to combine lexical items in the most plausible way, and that unique semantic constraints might allow the listener largely to by-pass syntactic factors (see Bever 1970a, for a discussion of this strategy). Corroborating evidence on the role of semantic factors in processing self-embedded sentences may be found in Schlesinger (1968). Both Blumenthal and Stolz conclude that since many subjects do not appear to be able to properly paraphrase or decompose multiply self-embedded sentences, even under liberalized circumstances, they just do not have command of the structures involved, and that consequently the sorts of processing mechanisms suggested by Miller & Isard are largely or entirely irrelevant to the processing that actually goes on. Note that Blumenthal and Stolz do not say anything as to why subjects have difficulties with multiply self-

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embedded sentences although they usually have no trouble with sentences involving only a single self-embedding. All that their data demonstrate is the fact that there are great difficulties in coping with sentences of the former kind. Basically their argument appears to be that if difficulties in processing self-embedded sentences are to be attributed to some difficulties in properly organizing or unscrambling information in short term memory, then a task format which minimizes demands on short term memory, by providing paper and pencil and plenty of time, should also eliminate these difficulties. Since it does not, this cannot be what is responsible for the results. Such objections are compelling if the only or principal reason for the difficulties in processing such sentences is the strain they impose on a limited temporary memory capacity during processing in real time, as in the situation actually employed by Miller & Isard. But, of course, this still leaves largely untouched the question of why subjects have difficulties with multiply self-embedded sentences, why they fail to understand such sentences properly, even with aids. What could be crucially informative is the locus of the difficulties, and the nature of the errors made. What is obviously needed are some more analytic studies, which seek to localize the difficulties subjects have with self-embedded sentences. This is what was attempted in an unpublished study by Phillips & Miller. They pointed out that memorial data might often not be particularly informative about comprehension, since after all people can memorize strings of words that make no sense at all, and developed a question-and-answer method to assess comprehension, and to determine where in particular comprehension went awry. They would present a self-embedded sentence and immediately afterward ask questions about the grammatical subject or object of each of its underlying propositions (actually, of course, only one question was asked for each test sentence). Consider a doubly self-embedded sentence such as 'The nurse that the cook that the maid met saw heard the butler'. The listener begins interpreting this sentence but immediately after 'nurse' there is an interruption and he must deal with the relative clause beginning 'that the cook'. While processing this relative clause and remembering 'The

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nurse' he is interrupted again by a new relative clause 'that the maid met'. Then he has to remember where to resume, and this is where difficulties should arise according to the Miller & Isard hypothesis, since the listener may not be able to remember both of the re-entry situations in their correct order. Consequently there should be particularly many errors regarding the underlying proposition for the in-between clause, e.g. in answer to the question 'The cook saw who?'. And this was indeed the case. While consistent with the Miller & Isard hypothesis in a number of respects, there were predictions for some related sentence constructions that were only partially supported, results which should lead to some caution regarding "the assumption that memory-load for a listener can be simply characterized in terms of re-entry situations and their order". Obviously there are problems with the question-answering technique in that one needs to remember a whole complicated sentence until the question is received and understood, and it is unclear what additional complexities this might introduce. There have been attempts to develop other sorts of analytic tasks by Rubenstein & Gilbert and by Stolz (see the citation in Miller & McNeill, 1969, and the reports of the Harvard Center for Cognitive Studies for 1965, and 1965-1966). Thus subjects may be asked to detect semantic anomalies in self-embedded sentences in a situation where the anomaly could be correctly reported only if the listener had understood the sentence by unscrambling the structure of the subordinate clauses. Indeed, in a study of this sort, Stolz found, consistent with the results reported above, that subjects had the greatest difficulty in detecting anomalies for the clause which was inside one other clause but outside another (the in-between clause). Now it may be that subjects have difficulties in coping with multiply self-embedded sentences for reasons of the sort cited by Miller & Isard. Or, if understanding of a sentence requires the identification of the unique logical function of each word in its deep structure propositions, they may have difficulties because in such sentences some terms have double functions, with the same noun subject of one clause and object of another (see e.g. Bever 1968a). Or they may have difficulties because multiply self-embedded

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sentences are complex in that they involve deep structure propositions with their components either interrupted or out of the canonical 'subject-verb-object' order. Whatever the reason the methodological point must be clear: only by use of analytic tasks can one hope to localize the difficulties in processing self-embedded sentences, and obtain data sufficiently specific to discriminate between hypotheses as to the grounds for such difficulties. So far we have been concerned primarily with difficulties in the 'computation' of the deep structure or comprehension of selfembedded sentences, we shall now consider some analytically designed research directed to determining whether such sentences have 'an especially complex representation in memory', whether memorial difficulties can simply be attributed to initial difficulties in understanding such sentences or whether there are additional memorial problems with them. Savin, reported in Wales & Marshall (1966), compared recall for surface structures derived by self-embedding or right branching from essentially the same underlying structure. Using his Archimedean technique self-embedded and right-branching sentences either followed or preceded by word lists were presented for recall. The results indicated that when sentences were followed by the word lists just as many words could be recalled correctly after either sort of sentence. "When the sentences were preceded by the word-lists, however, fewer self-embedded than right branching sentences could be recalled (after correctly remembered wordlists)". This is interpreted as demonstrating that both sorts of sentences take up equivalent amounts of 'memory-space' and that differences between them are due to differences in the difficulty of comprehending them initially (presumably on the assumption that there is enough computing capacity in immediate memory to determine the deep structure of either sort of sentence when the sentences come first but not enough left to do this for self-embedded sentences when word lists have been presented first and thus take up some of the capacity of immediate memory). Given that a full account of this research is not available, given results of the sort reported by Stolz indicating that subjects may not be able to understand

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self-embedded sentences even under optimal conditions, given some of the problems which we have noted earlier with regard to the Archimedean technique employed, and given some apparently contrary results in a quite analytic experiment by Foss & Cairns (1970) to be reported immediately below, the conclusion that difficulties with self-embedded sentences reside solely in the initial comprehension phase should probably be treated with considerable caution. Foss & Cairns conducted their study in order "to investigate the interrelations among the comprehension, rehearsal, and storage processes". They presented their subjects with word lists of varying length followed by either a right branching or a self-embedded sentence, and required first recall of the word list, then, if this was correct, recall of the sentence. In addition there was an Interruption condition where no words preceded the sentence during initial presentation but (two) words were inserted immediately after the sentence was presented and immediately before its recall was required. The results from this Interruption condition will obviously be of particular interest. In one respect it is similar to the condition in which no words were presented in that there was no additional load on short term storage during sentence comprehension, while in another respect it is similar to the condition in which two words were presented before the sentence in that the subject had to say two words before recalling the sentence. If the results for the Interruption condition are like those for the zeroword condition then any decrement in performance in the standard two-word condition must be attributed to the fact that some of short term storage is occupied while the subject is trying to comprehend the sentence. If the results are like those for the two-word condition then any decrements in performance in that condition must be otherwise explained, presumably in terms of interference with the rehearsal of the sentence, as storage interference effects. The results revealed that, as expected, performance was worse for self-embedded sentences than for right-branching ones, that sentence recall varied inversely with list length, and that recall of self-embedded sentences was impaired relatively more than that of right-branching sentences as list length increased. Further, the results for the Interruption

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condition essentially coincided with those for the two-word condition, suggesting that "giving the subject a word list to remember before he knows a sentence hampers recall of the sentence solely because of the requirement that the subject give back the words before he repeats the sentence", not because it preempts short term memory space at time of initial processing or comprehension. While the additional control of an Uninterruption condition with two words presented initially but immediate recall of the sentence (uninterrupted by any intervening recall of words) would have been desirable, the results are quite convincing as they stand, and consistent with the findings of Epstein (1969) and Glucksberg & Danks (1969) which we reported earlier. Essentially the results suggest that over and above greater difficulties in initial comprehension, the more complex self-embedded sentences are also more difficult to rehearse and store for later recall than are the simpler rightbranching sentences. While granting that their study does not really provide any real evidence for it, Foss & Cairns offer the speculation that the differential effect of interruption upon selfembedded and right-branching sentences could have occurred at the comprehension stage rather than at rehearsal or storage. This speculation is based on the general assumption that "unanalyzed linguistic material is forgotten more readily than analyzed linguistic material" together with the more particular, locally relevant assumption that at the end of input a self-embedded sentence is relatively less well analyzed than a simpler right-branching one. Obviously this issue cannot be settled in terms of the data at hand and requires further work. In terms of the foregoing it must be obvious that at present we know rather little, in any specific way, as to what it may be that makes it so difficult to understand multiply self-embedded sentences, and even less as to whether there are additional factors affecting memory for such constructions, and if so what these might be. And, speaking more generally, the same sort of conclusions would seem to hold for the other sentence constructions discussed earlier on. In most if not all cases one cannot tell what part of the memorial results is to be attributed to memorial factors, what part to com-

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prehension factors. One cannot tell whether, when it comes to memorial matters, syntactic factors are at all important in any ways beyond those which make it possible for the listener to interpret the sentence and obtain a semantic reading for it in the first place.

3 SENTENCE MEMORY AS SEMANTICALLY BASED

What sort of evidence is required to establish that sentence memory is not governed by syntactic factors, but, rather, that memory for sentences is semantically based, involving a 'meaning preserving code'? Basically one needs to show that (a) quite often there are verbatim errors at recall or false recognitions, and (b) that such errors or false recognitions which involve syntactic changes of various sorts are characteristically meaning preserving rather than meaning changing, essentially what is required is loss of syntactic information together with maintenance of semantic information. The first of these conditions is simple enough to satisfy for sentences of any complexity, the second condition (particularly when one considers the nature of the various sorts of syntactic changes involved) is the one of particular interest. If the sentence 'He called the girl up yesterday' is falsely recalled as 'He called up the girl yesterday', one can only safely infer that all surface structure information has not survived, but since the deep structure representation of these sentences is the same this could be what was stored in memory. However, if 'John lent the book to Mary' is falsely recalled as 'Mary borrowed the book from John' or if, to take a more florid example from Johnson-Laird (1970), 'James liked one particular painting very much and the painter sold it to him' is recalled or confused with 'One particular painting pleased James very much and he bought it from the painter' then one can draw the rather more powerful conclusion that matters of underlying semantics are important in the memory code, since the sentence pairs are more or less semantically equivalent and yet the erroneous sentences do not preserve the deep structure grammatical relations or perhaps even the underlying propositions. Errors in-

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volving paraphrases of the sort exemplified immediately above, if obtained under conditions of incidental recall where only a single recall or recognition test is involved, may constitute particularly relevant and convincing evidence with regard to a semantic hypothesis. If such errors occur even under conditions of intentional learning, where a verbatim set is commonly operative, they would constitute particularly impressive evidence for such an hypothesis, but if they do not this may not be very strong counter evidence, since as we noted earlier, results obtained under such circumstances may depend on some very special ecologically unrepresentative processing strategies adopted by the subjects, and thus may be largely artifacts of these strategies. Actually the second condition, that errors should be meaning preserving, should have been stated more generally, viz. that errors should be meaning related. However, it is difficult enough to specify meaning relations between single lexical items, and the job of characterizing meaning relations between sentences is even more intractable. While any complete account of sentence memory would obviously have to deal with the more general problem of characterizing meaning relations, for the initial purpose of establishing that memory for sentences is semantically based it may be sufficient to show that often errors are semantically roughly equivalent to the original items. The preceding should alert us to the fact that, in an important sense, far less is being demanded here of a semantic account than has usually been required of a syntactic account. With regard to syntactic accounts, these have usually sought to specify what sorts of structural syntactic properties were involved, and how they played the role they did, albeit usually with regard to matters of sentence comprehension rather than sentence memory. What seems to be the case is that such accounts are inadequate to the memorial data, that errors are often meaning preserving. What seems to survive is the message, or some abstract or précis of it which can provide the basis for an eventual reconstruction of the original sentence as the listener deploys his knowledge of the language upon the remembered meaning. But to say all this is not to say anything about the properties of the semantic

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structures involved, or how they play the role they do.

3.1 E R R O R S A S M E A N I N G PRESERVING

We shall begin by considering some studies which indicate in a general way that what survives in memory is semantic information rather than syntactic form, and then look at some work which is more analytic with regard to method and with regard to theory. While we could probably do as well by examining some early research by Binet & Henri (1894) or in more modern times research by Gomulicki (1956) or by Paul (1959), we shall take as our first example a recent study by Pompi & Lachman (1967) who proposed that memory for connected discourse is in the form of surrogate structures which may be themes, images, abstracts, or schemata of various sorts, that the critically important feature in the recall of prose is the "paraphrase of essential ideas", and that the particular wording is reconstructed from such surrogate processes at time of recall. They found that words thematically related to the content of a passage were often falsely recognized or recalled as having occurred in the passage, suggesting that it was meanings rather than particular lexical items that had been stored. While generally pertinent, the findings of such a study where memory was tested only for particular words do not have much to say directly with regard to the role of semantic factors vis a vis that of syntactic ones, so we turn now to some recent studies on 'Recognition memory for syntactic and semantic aspects of connected discourse' by Sachs (1967a, b). Sachs told her subjects that they would hear a short story after which they would be asked to judge whether a given sentence was identical to one they had heard or whether changed, and if changed whether changed in 'meaning' or in 'form'. The test sentences were unchanged, or differed either in meaning or in form (surface structure change only) or in voice from the original, or in terms of the substitution of a synonym for a particular lexical item. If the test sentence was presented immediately after the original sentence, retention was high for all sentence types. After 20 syl-

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lables of intervening material while recognition of semantic changes was high, recognition of other sorts of changes was already considerably reduced. By 40 syllables, and thereafter, while recognition of semantic changes remained high, recognition of stylistic changes, changes in voice, and lexical changes was quite poor. Insofar as formal changes were poorly recognized these results suggest that surface structure information is not maintained. Insofar as information about voice (or particular lexical items) is represented in deep structure, the fact that changes in voice or lexical items were poorly recognized suggests that sentence information is stored at a level more abstract than deep structure. Sachs argues that the original form of a sentence is held only for the short time necessary for comprehension, and that once a semantic interpretation has been made what is stored is "the information contained in the sentence" and "that later 'recall' is a reconstruction from the remembered meaning". Using rather different technique where subjects were exposed to a series of short sentences of varying grammatical form and then required to identify the form in which each sentence had appeared Bregman & Strasberg (1968) obtained results which led them to precisely the same conclusion as that reached by Sachs.3 3 There is a recent study by Begg & Paivio (1969) which indicates that under conditions where subjects are warned in advance that their memory for sentences will be tested, it makes a difference whether a sentence is made up of concrete or abstract materials, with semantic changes detected significantly more often than lexical changes for the former case, and the reverse true for abstract sentences. However, to judge from an example given in the instructions, 'The innocent occasion promoted a useless illusion', the abstract sentences were rather strange and perhaps in some measure unintelligible. In these circumstances where a sentence may be uninterpretable, and therefore held in mind as an unanalyzed or only partially analyzed string of words, a lexical change which always involved the substitution of a synonym or quasi-synonym for one of the sentence nouns may be relatively noticeable, and a semantic change, with the sentence hardly interpretable in the first instance, less so. While Begg & Paivio reject this possibility because of the absence of any main effect of sentence type in the results, their argument is not completely convincing and the implications of these findings are unclear. It might be noted that Tieman (1971) studying recognition memory for comparative sentences was not able to replicate Begg and Paivio's concrete-abstract sentence effect. Memory for

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There is work by Fillenbaum (1966) which indicates that people remember the gist of a sentence, not its syntactic structure, nor even perhaps its underlying propositions. For the case of sentences built around contradictories such as 'open/closed', 'alive/dead', he found substantial confusions on a recognition task such that e.g. 'The door is not closed' was more often falsely recognized as 'The door is open', a sentence similar in meaning, than as 'The door is closed', a sentence different in meaning but similar in underlying propositions. The fact that analogous effects were generally not obtained for sentences involving contraries such as 'hot/cold' or 'full/empty' where a sentence such as 'The plane is not full' is not equivalent in meaning to 'The plane is empty', is further testimony to the subjects' sensitivity to semantic considerations. We have already mentioned a subsequent study by Fillenbaum (1968) which revealed that during paired associate learning of sentences in various grammatical constructions semantically equivalent sentences built around 'converse' verbs were particularly likely to be confused. Thus when the correct response would have been 'John sold the book to Mary' the sentence 'Mary bought the book from John' was characteristically the most common erroneous response. Again one finds that, even under circumstances of intentional rote learning with emphasis on verbatim performance, sentences which are equivalent in meaning, although they differ in the basic grammatical relations in which their constituents enter and in their deep structure propositions, are the ones most likely to be mutually confused. We know that subjects have a remarkable capacity for remembering the meaning of sentences, or at least for remembering meaning was better than memory for exact wording when concrete materials were presented, but memory for exact wording was not better than memory for meaning when more abstract hard-to-visualize sentences were presented. In neither of the relevant cases did the data support Begg and Paivio's prediction that the relative percent of errors which maintain meaning would be higher for the concrete sentences than for the abstract ones. While there are various procedural differences between the Begg and Paivio study and that conducted by Tieman, it is not obvious how these might account for the differences in the results. At the very least the results of the latter study call into question the generalizability of Begg and Paivio's findings.

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whether or not a particular sentence has occurred previously in a list of sentences. Thus Shepard (1967) gave subjects an inspection series of over 600 sentences followed by some 68 sentence pairs, with one sentence in each pair an old one, one a new one and subjects required to decide which was the old sentence, which the new. He found that subjects were correct nearly 90 % of the time (this held even for a couple of subjects exposed to an inspection series of over 1200 items — now performance dropped from the previous 89 % correct to 88 % correct). But what about recognition memory for sentence wording as compared to sentence meaning? Begg (1971) presented subjects with about 400 sentences using a continuous recognition paradigm. Any given sentence might be a new one, an old one, or a paraphrase of one that had occurred previously, with paraphrases involving "formal (order, addition, deletion, and voice change) and lexical (synonym substitution) changes" of the sort employed by Sachs. For each sentence the subject was required to decide whether or not he recognized the meaning as one previously presented, and, if he did, whether or not the exact wording was that of an earlier sentence. While accuracy of meaning judgments decreased as a function of the lag between an item and its repetition (or the occurrence of its paraphrase) overall performance with regard to meaning judgments was high, on the average .86 even after 64 intervening items, and "meaning judgments were no less accurate if the test sentence was a paraphrase than if it was identical to the original". Accuracy of wording judgments although above chance was only moderate with an overall average of about .62, and was not systematically related to the lag between an item and its repetition, or to meaning judgments. Begg used both visual and auditory modes of presentation and found meaning judgments to be relatively little affected by stimulus modality, while there were some differences for wording judgments in favor of visual presentation. In general these results which indicate that memory for the meaning of a sentence is independent of memory for its wording, strongly support a position that argues that wording information is stored for a short time only, perhaps just long enough for comprehension to take place, and

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that after that recall depends upon some sorts of reconstructive processes. How the meaning of a sentence may be maintained is of course an open question. Although the results are certainly consistent with Begg's suggestion "that the meaning of a concrete sentence is represented in memory as a non-verbal spatial image, while the words are reconstructed from the image at retrieval", a suggestion based upon the fact that most of the sentences involved had been rated concrete and upon the fact that most subjects claimed that they remembered the sentences as pictures or images, they surely do not require that interpretation. The principal importance of the results is in showing that it is meaning rather than form that survives, and in posing questions as to how this might have come about. In Sachs' study subjects were able to retain some stylistic information and in Begg's study, too, accuracy of wording judgments was above chance. What might this mean? As Sachs notes, the subjects knew that they would be questioned about the materials, presumably subjects often were trying to remember the exact wording of what they encountered, so that these results can only provide "an upper limit to the ability to recognize form after the intervals tested". The results indicate that subjects can preserve some stylistic or surface information about sentences, if warned in advance that their memory will be tested. The question is whether such information is usually preserved, or whether these results are a consequence of some information processing strategies peculiar to the experimental situation (characteristically) employed. It could be that after a sentence has been understood both underlying semantically relevant information and information about its superficial structure are available for retrieval, with the latter sort of information prone to relatively rapid decay. Or it could be that under normal circumstances once a sentence has been understood the listener maintains control only of the relevant semantic information, which: ...may be a good deal less than the sum of all the superficial information in the sentence that would be required for immediate recall... [and that]... semantically relevant deep structure information is the exclusive

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product of comprehension; and differential decay is simply the result of the subject's artificial attempts to remember the superficial information which he normally forgets (Wanner, 1968). One possible, obvious, if experimentally expensive approach to this issue might be via the use of an incidental memory paradigm. What if one does not warn the subject that his memory will be tested, realizing circumstances more like those of normal comprehension? In a very ingenious experiment Wanner (1968) tested for incidental memory of a sentence in the instructions, and found that after some 50 interpolated syllables recognition of a semantic change was high, nearly 100%, whether subjects had been prewarned or not, whereas recognition for a stylistic change was substantially lower even when subjects had been prewarned, and no different from chance for subjects in the incidental or unwarned condition. Such results cannot tell us whether, for the case of unwarned subjects, semantically irrelevant, superficial information is lost immediately, or whether it just decays rapidly in the course of the ten seconds or so that elapse during the passage of 50 syllables, and it would be of considerable interest to know which is the case.4 But in general such results do strongly suggest that while meaning relevant information is retained well under normal conditions of comprehension, little if anything is remembered for any length of time about the superficial structure and stylistic properties of the materials. Some findings of an 'unsuccessful' experiment mentioned by 4 There are some data that may be relevant here. Present a singly self-embedded sentence such as 'The soldiers the Indians saw killed the buffalo' to a subject, and then, immediately afterwards, probe with a noun-verb pair, the subject being required to decide as quickly as possible whether that pair occurred in the sentence. Under these circumstances pairs that form deep structure units relevant to the correct semantic interpretation such as 'soldiers killed' or 'Indians saw' are recognized faster than other combinations, this being independent of the adjacency of the terms in a pair in the acoustic signal. The above suggests that hearing and understanding a sentence involves some sort of immediate structural reorganization, and while, of course, this does not prove that the original manifest structural relations are lost at the same time, it is hard to see what further function or role they can have (the example and the argument are due to a lecture by Philip Gough).

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Johnson-Laird (1970) are quite consistent with the above conclusion. To quote: "...when subjects were confronted with an unexpected test of their ability to recognize the sentences of a brief spoken story, they recalled actives as passives just as often as they recalled passives as actives. Yet their memory for meaning was extremely good." Using a short passage including as a critical sentence 'John liked the painting and bought it from the duchess' Johnson-Laird & Stevenson (1970) showed that upon a recognition test verbatim memory (and thus also memory for deep structure relations) was significantly better for subjects warned that their memory would be tested than for subjects not so warned. However, when it comes to semantic accuracy, involving response to meaningfully equivalent paraphrases such as 'The painting pleased John and the duchess sold it to him', there was no difference between the subjects in the intentional and incidental learning conditions, with performance high in both groups. Thus subjects appeared to retain syntactic information only if they knew that their memory was going to be tested. Consider one further experiment making use of an incidental recognition task in the context of a study of the meaning relations obtaining among 'if', 'and', and 'or'. Threats or warnings may be phrased as conditionals 'If you do that I'll hit you', as sentences phrased conjunctively 'Do that and I'll hit you', or as negative disjunctions 'Don't do that or I'll hit you'. These versions are different in surface form and presumably in underlying grammatical structure as well, and yet they are roughly equivalent in meaning. After performing a cover task involving a variety of sentences phrased in these different ways, subjects were given a new series of sentences, and for each required to decide whether or not they had encountered it earlier. Under these circumstances there were many confusions, and sentences different in phrasing but semantically equivalent to previously presented sentences were often falsely judged to be old sentences (Fillenbaum, in preparation). Results of this sort lead us to assent to JohnsonLaird's suggestion (1970) "that all forms of syntactic structure are normally lost to memory within a few seconds" and to conclude that what is normally stored is semantic information.

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Note, however, that, to this point, even if we have succeeded in demonstrating that sentence memory is semantically based, we have had essentially nothing to say as to how semantic information may be represented, stored, and lost (with the exception of a passing mention of Begg's speculation following Paivio, see e.g. Paivio (1970), that the meaning of a concrete sentence may be represented as a nonverbal spatial image). The reason for this is very simple — the studies which are most directly relevant are ones which tend to show the inadequacies of syntactically based formulations but are characteristically not sufficiently analytic to support specific hypotheses as to the nature of the semantic representation involved. Given the current or at least recent state of semantic theory, it is perhaps not surprising that these studies generally have not offered any specific hypotheses as to properties of the semantic representations which appear involved in sentence memory. Some research by Clark constitutes one of the few exceptions to this tendency.

3.2 A N EXAMPLE OF SOME PROPERTIES OF A SEMANTIC REPRESENTATION RELEVANT TO SENTENCE MEMORY

The work of Clark and his associates (Clark & Card, 1969; Clark & Clark, 1968; Clark & Stafford, 1969) not only seeks to demonstrate that memory for sentences has a semantic basis but, further, it attempts to characterize the form such knowledge takes and the processes by which it is retrieved. Essentially the view is that at recall the subject tries to reconstruct a sentence from the semantic information still available to him, and that the way in which it is stored and retrieved will determine the degree of success and the nature of the errors that will be made. A central notion in all this work is the distinction between marked and unmarked terms, where the unmarked term is simultaneously the label for a category or dimension and the label for one member of that category or pole, and the marked term can serve only the latter role, as e.g. in the contrast between man and woman. This involves the assumption that in the abstract representation of the information in long term

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memory the marked form is always more complex by one additional feature, and that memorial processes are such that this additional feature may be lost independently, with the result that at recall there is a systematic drift toward the simpler unmarked form. The principle of lexical marking plays a central role in the interpretation of the results of all the memory studies, and it is important to remember that this principle is not some specially contrived ad-hoc notion developed by Clark, but rather a general principle that has figured importantly in linguistic analysis and for which there is independent linguistic evidence (on this see e.g. Greenberg, 1966; Lyons, 1968, 1970). We shall indicate, in some detail, how this approach was applied to the study of memory for sentences containing verbs of varying form, and will also briefly mention two studies, one of complex two-clause sentences involving the ordering of events, and one of comparative and equative sentences. Clark & Stafford (1969) argue that a verb is stored in long term memory as a set of semantic features. They specify these as involving the contrasts between (a) present time and past time, (b) limited duration and unlimited duration (progressives versus nonprogressives), and (c) completion and noncompletion (perfect verbs versus nonperfect verbs), with the semantic features of a verb regarded as restrictions on its interpretation which more specifically delimit the meaning of the action described so that with the specification of any semantic feature "interpretation becomes more restricted, less general". They argue that in memory, verbs should simplify semantically by losing their restrictions, in each case going from the more complex 'marked' form to the simpler 'unmarked' form. Thus progressives should be recalled as nonprogressives and perfect verbs as nonperfect verbs, with loss, respectively, of the restriction with regard to duration and completion. These predictions, so far, are the same as those that may be made on the basis of a syntactic theory. If one assumes that a verb can be decomposed into an auxiliary plus main verb, with auxiliary involving an obligatory tense marking plus optional aspectual markings for perfective and progressive, and if verbs are factored into syntactic entities in memory, forgetting should involve

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simplifications of the auxiliary such that verbs where progressive or perfective aspects or both are specified, should "simplify to verbs without these aspects", while presumably simple verbs should characteristically stay that way. However, there are cases where the predictions from a semantic feature account and on the basis of a syntactic account diverge. On the basis of a semantic feature analysis present perfect verbs should simplify to simple past and present perfect progressives to past progressives. On the basis of a syntactic account if there is any tense simplification it should be toward present tense, as present is "the syntactically unmarked or simpler form in English". Note that the simple semantic change from present perfect to simple past requires two syntactic alterations, a change in tense from present to past (toward the more complex syntactic form) plus a loss of perfective aspect. Presumably errors involving two properties or features should be less frequent than those involving only one change, so on a syntactic theory loss of perfective aspect should be more frequent without change of tense than with it, while such changes, e.g. from present perfect to simple past, should be relatively common on the semantic feature hypothesis since they involve change in only one semantic property, i.e. a dropping of the restriction 'completed by present time'. Subjects were presented with sentences cast in eight verb forms, with verbs either present or past, either progressive or nonprogressive, and either perfect or nonperfect. Recall was cued by the subject noun from each sentence. At recall verbs underwent simplification such that perfect verbs were often recalled as nonperfect verbs, and progressives as nonprogressives. These results could be considered as evidence either for syntactic or for semantic simplification. However, present perfect verbs were often recalled as simple past verbs and present perfect progressives as past progressives and there was a distinct drift from present to past tense in recall errors, results which are consistent with the semantic account but difficult to interpret in terms of a syntactically based theory. While a revised syntactic formulation along the lines developed by Bach (1967) could handle some of these latter results, other results, particularly the bias toward past tense, cannot be

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explained. Thus all the changes could be interpreted as involving loss of one or more semantic features resulting in simplification in the interpretation of the verb. Essentially the recall of a complete verb was affected mainly by its semantic simplicity—complex verbs were often simplified, and thus poorly recalled. It might be mentioned that direct judgments of verb similarity yielded results quite parallel to those obtained on the memory task, e.g. subjects judged the pairs 'has watched' and 'watched', and 'has been watching' and 'was watching', respectively, to be highly similar in meaning. This may be considered as a further piece of corroborating evidence that meaning properties, or similarities in meaning as defined by overlaps or relations in semantic features, constitute an important factor in sentence memory. Actually the results are stronger than this, for confusions between meaningfully related forms are not symmetric but characteristically show systematic biases, permitting some inferences as to which is the simpler 'unmarked' form, which the more complex, 'marked' one. With regard to memory for complex two-clause sentences involving the ordering of events, Clark & Clark (1968), sentence confusions indicated that subjects remembered three semantic distinctions: temporal order, order of mention, and the main-subordinate relation of the two described events. The results could be accounted for if one assumed that order of mention may be marked, if the sentence is such as to indicate that the event mentioned first actually occurred second, that the main-subordinate relation may be marked, if the subordinated event is mentioned first, and that in recall there is a shift toward the unmarked forms. For some questions to whether difficulty in recalling the exact form of a sentence reflects difficulty in comprehension, see Smith & McMahon (1971); for some comments on their analysis see Clark (1972). In the case of comparative and equative sentences phrased either positively or negatively and involving either unmarked adjectives, like good, or marked ones, like bad, it was again found that subjects made systematic errors in recall, which were mostly predictable from a semantic feature theory — thus unmarked adjectives were often reconstructed from marked ones and positive sentences from

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negative ones, Clark & Card (1969). Looking back at the studies that we have reviewed one can see that they make a strong case against any syntactically based theory of the memory for sentences, that they clearly appear to demand some sort of interpretation in semantic terms. Others have, of course, reached similar conclusions with regard to the role of syntactic and semantic factors in sentence memory. Thus, e.g. Weisberg (1971) on the basis of work using an intrasentence word associations technique, where the subject is given a word from a previously presented sentence and asked to repond with whichever other word from that sentence comes most readily to mind, argues that "sentence structure serves as the basis for sentence interpretation but structure per se plays little part in sentence storage". However, the demonstration that sentence memory is semantically based is really more in the nature of the statement of a problem than anything else. If sentence memory is semantically based one needs to determine in some detail what properties the necessary semantic representations may have, and the fate of such properties over time. For various reasons, not the least of which was the overwhelming priority given to syntactic matters (because that was where the action was) together with the almost complete absence of viable semantic accounts, there has been very little work by psycholinguists directed to these problems. And, obviously, these are the problems where work needs to be done. Indeed the justification for presenting an example from the work of Clark at some length is precisely that this represents one of the few studies that goes beyond showing that meaning equivalent but syntactically different sentences are confused, that rather it constitutes an attempt to specify meaning relations obtaining among sentences and to predict errors at time of recall in terms of some relatively differentiated, specific properties of the putative semantic representations involved. Notice that as soon one does offer a relatively differentiated structural account in semantic terms, there arise problems very similar to those facing any structural account in syntactic terms, i.e. questions as to whether memorial data are revealing of memory, of comprehension, or what; questions as to the nature of the memorial processes

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operating now on semantic structures, etc. While such questions can perhaps be avoided so long as one is just seeking to establish the fact of semantic determination in memory, it turns out that they have only been postponed once one attempts to offer some specific hypotheses as to the nature of the semantic properties and representations involved.

3.3 MEMORY NOT FOR SENTENCES BUT FOR KNOWLEDGE BASED ON THE INFORMATION IN SENTENCES

We have been writing as though the central issue were memory for the exact meaning of single, individual sentences. There is perhaps some excuse if not justification for this insofar as the great bulk of the experimental work has dealt with memory for individual sentences, and, insofar as there has been concern with problems of meaning, it has been principally with regard to survival or distortion of information explicitly presented in single sentences. However, in many respects this may constitute a very gross simplification which misrepresents the task faced by the listener and the ways in which he may seek to cope with it, for the listener may often (need to) draw inferences from the information available in single sentences and compound and make deductions from the sets of sentences he encounters. We have suggested earlier that what survives is the gist of a message or some abstract or précis of it, without saying anything as to what might be involved in arriving at such an abstract. It may well be that this requires not only information based on the exact meaning of the individual sentences presented, but also information that can be inferred directly or indirectly from these sentences, singly or more likely in combination, given ordinary circumstances of continuous discourse. To take an example, after Tieman (1971), if I am told that 'John is tall, and he is shorter than Bill', I can deduce that, at least, 'Bill is tall', and this information may be part of the information entered into memory, such that on later test I may falsely recognize the sentence 'Bill is tall' which I never actually encountered. Or, to take another example from

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Bransford, Barclay, and Franks (1972), if I am told that 'There is a tree with a box beside it, and a chair is on top of the box. The box is to the right of the tree' I may infer that 'The chair is to the right of the tree' or that 'The tree is to the left of the chair', and may later falsely recognize or recall these propositions or sentences. Thus memory may not be for individual sentences so much as "for the overall semantic situations that such sentences describe", sentences may be viewed as: information which subjects can use to construct semantic descriptions of situations. These constructed descriptions may contain more information than is represented in the linguistic inputs and hence a purely linguistic analysis of the input sentences will not adequately characterize the information available to the listener (Bransford, Barclay, and Franks [1972], my italics). If indeed it is the case that when some relationship or fact is a reasonable deduction on the basis of the information explicitly provided, subjects will tend to recognize that deduction as something they have actually encountered, then any account of memory for information will also require a characterization of the inference strategies or the 'natural logic' employed by the subjects. Clearly anything of this sort and scope is quite beyond our reach at the present time. However, the issues involved are so significant, and questions as to the difference between memory for exact meanings and memory for what may be inferred are so important that it may be worthwhile to look briefly at some recent work which has begun to approach these problems. First we shall consider some work on 'linguistic integration and retention' that suggests that subjects may integrate the information involved in a number of semantically related but non-consecutively presented sentences into holistic 'semantic ideas' where these complex ideas contain more information than any particular sentence actually encountered (Bransford & Franks, 1971; Franks & Bransford, 1972), and then we shall examine some further work (Bransford, Barclay & Franks, 1972) which suggests that sentences may "have semantic implications that extend beyond the information they directly express", that one may (falsely) remember

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having encountered information that, given knowledge of language and the world, was inferable from the information actually presented. Both sorts of work are on the same theme of going beyond the givens, but the latter studies are particularly interesting in that they show that subjects may not only compound explicitly provided information into more complex forms, but that they may make use of information that is only implicitly provided. While the first sort of work might be interpreted as requiring only purely linguistic processes such as those involved in a relative construction which embeds one sentence within another, the second sort of work surely goes beyond purely linguistic processes, as usually conceived, and must involve the application of some sort of 'natural logic' to work out what is implicit from what is actually presented, given various sorts of prior knowledge. In a sense, of course, if one quits for a moment the station of the experimental laboratory all this may seem quite obvious and the demonstration of a truism. But given the tunnel vision with which we are often afflicted as researchers the opening up to experimental analysis of this area is very welcome. The following simple sentences: (1) 'The ants were in the kitchen', (2) 'The jelly was on the table', (3) 'The jelly was sweet', and (4) 'The ants ate the jelly', which we may call ONES, can be variously combined into more complex sentences. Thus by combining (3) and (4) we may get a TWO, viz. 'The ants ate the sweet jelly', by combining (2), (3), and (4) we may get a THREE, viz. 'The ants ate the sweet jelly which was on the table', and by combining all the simple or elementary sentences we may get the FOUR, the maximally complex sentence, viz. 'The ants in the kitchen ate the sweet jelly which was on the table'. Now consider a situation where a subject initially encounters a number of the elementary sentences and of their intermediately complex combination i.e. some ONES, TWOS, and THREES, and then at time of test is confronted with ONES, TWOS, THREES, and the FOUR, where some of these are sentences originally encountered and some sentences he has not heard before, and he is now required to say which sentences in the new set he had 'actually heard before', and to indicate his confidence in these

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judgments. This, with various controls, was essentially the experimental situation employed by Bransford and Franks (1971) and Franks and Bransford (1972), the main difference between the two studies being that the former made use of more concrete sentences, as illustrated above, while the latter made use of more abstract materials, e.g. a FOUR such as 'The unrealistic goals proposed by the leader resulted in frequent disillusionment'. Since the results of both studies were quite similar they will be discussed together. Notice that during acquisition subjects were never exposed to the maximally complex sentence, the FOUR, and that it, as well as some of the other sentences presented in the recognition task, contains "combinations of relations never expressed in any single sentence presented during acquisition", and that these separate pieces of information were originally encountered interspersed with other information from different sentence sets. One may now ask two questions with regard to the recognition results: (1) Can subjects distinguish between 'new' and 'old' sentences?, and, perhaps more interesting, (2) To what extent are the recognition ratings a function of the number of semantic propositions involved in particular sentences? As to (1) with the possible exception of ONES there was no difference in performance on 'new' and 'old' sentences; in general subjects "could not discriminate novel sentences consonant with the ideas acquired during acquisition from sentences that they had actually heard". As to (2) there is a very clear monotonic almost linear relation between the amount of semantic information in a sentence and recognition judgments. Subjects are most confident in their response to the FOUR which expresses all the semantic relations characteristic of the complex, complete idea, even though none of the originally presented sentences contained all such information, and subjects "became less confident of having heard a particular sentence as a function of the degree to which a sentence fails to exhaust all the semantic relations characteristic of a complete idea", i.e. recognition ratings are clearly ordered with FOURS > THREES > TWOS > ONES, with control NONCASE sentences which were neither heard during acquisition nor consonant with ideas presumably acquired rated lowest of all. Taken together the

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above results suggest that subjects may have integrated or compounded the partial information in the various semantically related sentences, presented non-consecutively, into a single unified semantic representation, into a memory organization as one complete, complex idea, and that later recognition performance is a function of the relation between any particular test sentence and this complex representation. Thus while there may be highly accurate specific sentence recognition when sentences presented in acquisition are semantically unrelated, specific sentence recognition may virtually disappear when intersentence relations are present. However, a question may be raised as to the appropriateness of the test instructions employed by Bransford and Franks. If one wishes to argue that the information in the various individual sentences is integrated into a unified semantic representation or a single complex idea which then represents the sole basis for the assessment or recognition of future test sentences then, on the recognition test, it does not seem appropriate to ask subjects to decide "which exact sentences" (my italics) they had heard during acquisition, but rather one should ask them to indicate which sentences had the same meaning as sentences encountered previously. At the very least, given the kind of interpretation offered by Bransford & Franks, one ought to expect that the sorts of results actually obtained with verbatim instructions would also be obtained if meaning instructions were to be employed. Just this was done by Katz (unpublished MS, 1972) who essentially replicated the work of Bransford and Franks using both actual or verbatim instructions and meaning instructions. Performance on 'new' sentences versus that on 'old' sentences was not affected by the instructions, again subjects essentially could not discriminate between these two kinds of items. Using the actual or verbatim instructions Katz replicated the earlier results, finding again a monotonic, essentially linear effect as a function of the number of propositions involved in each test sentence. However, there was a significant interaction between instructions and the linear trend for sentence complexity, the curve for recognition score as a function of sentence complexity lying considerably higher and being considerably flatter

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under meaning instructions than under verbatim instructions, with ratings for FOURS, THREES, and TWOS practically identical under the former instructions. What is one to make of this? We have been assuming that once a complete semantic representation has been arrived at and stored, memory for the components entering into such a representation is lost. If one assumes further that under meaning instructions a test sentence is assessed in terms of whether its meaning is included in the meaning of the complex, complete representation then, in general, the sorts of results obtained by Katz are to be expected. But then how is one to interpret the results obtained under verbatim instructions? Why should such instructions result in a recognition function linear in sentence complexity? At this time perhaps the only conclusion that can safely be drawn is that information in the various separate individual sentences is integrated into a complete complex semantic representation, recall that whatever the instructions Katz found that FOURS which had never been encountered were recognized at least as well as THREES and TWOS that had occurred previously, but that is not clear how a subject proceeds in assessing a test sentence against such a complex, unified representation. Presumably it is the matter or fact of such information compounding that is presently of prime interest, and that appears not to be challenged by Katz's results. Let us turn now to some studies which appear to show that subjects may remember not only the information explicitly stated in the materials they encounter, but also information implicit there, information that can be inferred or deduced from what is explicitly given. Tieman (1971) has shown that if a sentence pair such as 'John is tall. John is shorter than Bill' is presented, where the inference that 'Bill is tall' can be made, then 'Bill is tall' is more often falsely recognized at later tests than if the original sentence pair had been 'John is tall. John is taller than Bill', where the inference 'Bill is tall' does not necessarily follow. And, as Tieman points out, this is not a result that can be explained in terms of any simple hypothesis of sentence storage in terms of base strings, for the base strings for 'John is tall. John is shorter than Bill' do not include 'Bill is tall', while those for 'John is tall. John is taller than Bill' do include 'Bill is

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tall', and yet mistaken recognition of 'Bill is tall' is more common in the former case where it is inferable and absent from the base strings, than in the latter case where it is not inferable but present in the base strings. Let us look next at some work by Bransford, Barclay & Franks (1972), first at studies on recognition memory for information implicit in or inferable from single sentences, and then at studies of a similar import but now for cases where interest is in memory for inferences that may be drawn from sets of semantically related sentences, essentially short paragraphs. Let us examine two sentences: (1) 'Three turtles rested beside a floating log, and a fish swam beneath them', and (2) 'Three turtles rested on a floating log and a fish swam beneath them'. In many ways (1) and (2) are very similar, but there is at least one important difference between these sentences. In the case of (1) the fish may or may not have swum beneath the log, the matter is left open. However for (2) given knowledge of the meaning of the word 'on' we know that since the fish swam beneath the turtles and they were on the log it must have swum beneath, i.e. if X is on Y and Z is beneath X then, then for the sort of scenario under consideration, Z must be beneath Y. Now consider two further sentences differing from the original sentences only in a change with regard to the final pronoun, viz. (3) 'Three turtles rested beside a floating log and a fish swam beneath it', and (4) 'Three turtles rested on a floating log and a fish swam beneath it'. As argued above (3) may or may not obtain given (1), but given (2), (4) follows. We may present subjects with sentences of type (1) and type (2), as well as control filler sentences, telling them to listen carefully so that later they may be able to answer questions about the sentences. We may then provide a recognition task where subjects are confronted with sentences of type (1), type (2), type (3), and type (4), and ask them to indicate the exact sentences encountered earlier, and to rate their confidence in these judgments. The crucial question of course is whether subjects can distinguish between sentences of type (2) and type (4), where the previously presented sentence (2) and the previously non-presented sentence (4) describe the same situation,

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where (4) may be inferred if (2) has been given. The results are quite clear — subjects could not tell which had occurred, (2) or (4), and gave them equal ratings. Thus when subjects could come to the same conclusions whether 'them' or 'it' had been used they revealed no knowledge of which pronoun had actually occurred earlier. On the other hand they had no trouble in judging correctly that (1) had appeared earlier and that (3), which does not necessarily follow from (1) or describe the same situation, had not appeared earlier. There are some further corroborative recall results which confirm that indeed these memory differences are pronoun specific, that for sentences of type (2) and type (4) subjects had great difficulty in keeping the pronouns straight. Next consider a case involving not memory for inferences that may be drawn from single sentences, but rather memory for inferences that may be drawn from semantically related sets of sentences. Consider a paragraph such as: 'There is a tree with a box beside it, and a chair is on top of the box. The box is to the right of the tree. The tree is green and extremely tall'. Given this information the sentence 'The chair is to the right of the tree' follows, since if X is to right of Y and Z is on top of X, then Z must also be to the right of Y. Also given our knowledge of the meaning of 'right of' and 'left of' it follows that 'The tree is to the left of the box', and that 'The tree is to the left of the chair'. If we use the information provided in the paragraph to constitute a description of the situation all the above propositions, as well as others e.g. 'The box is underneath the chair' will hold. Following the same logic as earlier one may ask if subjects are prone to falsely recognize information implicit in the information actually provided them, whether they will remember the facts in a paragraph in such fashion as to be unable to discriminate between information explicitly asserted and information implicit and inferable from what has actually been asserted. The results indicate that if the original spatial terms are maintained, old sentences ('The box is to the right of the tree') are in fact recognized significantly more often than permissible inferences ('The chair is to the right of the

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tree'), indicating some tendency to remember the linguistic form in which information was originally expressed, but that the latter (i.e. permissible inferences) which may be termed 'situation-preserving responses' are recognized significantly more often than situation-distorting responses, such as 'The box is to the left of the tree'. When spatial terms are exchanged there is no difference between pseudo-old and inferred propositions which are situationpreserving viz. 'The tree is to the left of the box' and 'The tree is to the left of the chair', and both of these are recognized significantly more often than situation-distorting sentences such as "The tree is to the right of the box'. The proportion of responses consonant with the complete semantic description suggested by the passage is essentially the same whether the spatial terms 'right of' or 'left of' are employed, suggesting that what is important is the cognitive schema the subject has built on the basis of the information provided him, rather than the specific wording or phrasing of that information, or what is explicitly asserted in that wording or phrasing. In all the recognition studies reported in Bransford, Barclay & Franks subjects were asked to identify the "exact" actual sentence they had encountered previously, and again one may raise questions as to the appropriateness of such instructions. Given the general sort of analysis offered by Bransford, Barclay & Franks all that should have been required of subjects ought to have been the identification of sentences consistent in meaning with those encountered earlier. One may argue, however, that the results actually obtained under verbatim instructions a fortiori would have been obtained even more strongly under the more appropriate meaning instructions, which specify a more lenient recognition criterion. The matter may be worth checking out experimentally, nevertheless, for contrary or different results with meaning instructions would be very puzzling, and throw the whole account into question. In a sense two partly separable questions may be involved. We may ask (1) whether a person can discriminate between information actually, explicitly provided and information derivable from what was provided, whether there are any differences between memory

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for the exact meaning of a sentence and memory for what can be deduced from that meaning, and we may ask (2) whether a person can muster information never actually encountered, but derivable from or consistent with information previously encountered (in circumstances where such performance cannot be attributed simply to inference effects at time of testing). A negative answer to (1) is of course of great interest, but a positive answer to (1) by no means rules out a positive answer to (2). In some ways (2) may be the more generic, basic question if we are interested in how knowledge or a cognitive representation is built up and the uses to which it may be put. A person may not be able to recall exactly what he had heard earlier, he may know that he did not actually hear a particular test sentence offered for recognition, and yet he may claim, correctly, that the information it contains follows from or is consistent with the forgotten message. If this sort of thing can happen, as seems very plausible, it poses some very important and difficult questions. One way to speak of the results obtained by Bransford, Barclay, & Franks (1972), which they favor, is to say that sentences constitute sources of information "which the listener assimilates to his existing cognitive knowledge", that linguistic information is used together with previous knowledge to construct semantic descriptions, that it "is the synthesis of present input and previous knowledge which determines the nature of the semantic descriptions one constructs" and that allows one to go beyond the information directly and explicitly expressed in the sentences encountered. Perhaps one should put it even more strongly, noting that this interaction between present input and pre-existing knowledge not only allows or permits one to go beyond the present givens but rather makes it impossible not to do so, that just as there is information loss as one abstracts from the linguistic materials one encounters, so, equally and just as inevitably, there is information gain consequent upon the amalgamation of new linguistic information with already available knowledge. To make such a suggestion is easy enough, to say something as to what information is lost or gained and regarding the principles governing such losses and gains is, of course, now largely beyond

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our power. And one of the principal reasons for this is simply that we know very little about the abstract 'logical' form in which information is stored, the format, as it were, of meaning, or concerning the inference rules by which the information implicit in particular sentences or sets of sentences becomes accessible, or with regard to the ways in which inference rules may operate to relate particular messages to a person's general knowledge; for one recent attempt at approaching this problem see Kintsch (1972). Recall that the examples we have considered involved only some very simple cases of information compounding, or the drawing of very simple one-step inferences. We have very little knowledge as to what happens when more subtle sorts of inferences are involved even for the case of single sentences, say as regards the recall of what is presupposed or entailed by a sentence, over against recall for what is asserted by it. For example, if the subject hears a counterfactual conditional 'If Bill had caught the plane, he would have arrived on time' could it be that later he might falsely remember encountering the presupposition of this sentence, viz. 'Bill didn't catch the plane' or a possible implication of it, viz. 'Bill didn't arrive on time'? 5 Note that whether for this relatively simple case or for more complex cases involving the integration of information over a series of sentences we know hardly anything about the sorts of inference rules that a person might tacitly employ in processing new information and relating it to pre-existing information. About all we can say is something regarding what they are not. Thus, for example 'If.. . then. . . ' is not likely to be taken as material implication, and the fact that the inference 'Bill didn't arrive on time' in the example given above may not be logically valid does 5

There is now evidence that in fact this does happen. Thus, for examples of the sort mentioned, subjects falsely recognize both presuppositions and implications of a previously presented counterfactual conditional. Indeed they also falsely recognize related causal sentences, e.g., given "If Bill had caught the plane he would have arrived on time" they may falsely recognize "Bill didn't arrive on time because he didn't catch the plane", and, conversely, given the causal they may falsely recognize the counterfactual conditional (with the latter effect the stronger one). See S. Fillenbaum, "Information amplified: memory for counterfactual conditionals" (in preparation).

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not in any way say anything as to whether or not it may be made. We have been speaking as though these effects, call them information amplification effects, are effects at time of information input and comprehension, as the new information in a sentence or sentences feeds into, amalgamates with, and modifies and is modified by already existing information or knowledge. But it is at least possible that in good measure these are read-out effects as the subject scans the information available to him at the time that memory is being tested, and tries to determine what messages and thus sentences follow from or are consistent with that information. In general we just do not know how to parcel out these effects. Just to raise questions of the sort mentioned above is to testify to the breadth and depth of our ignorance in these matters. If memory is not for sentences but for knowledge based on the information in sentences as this interacts with already pre-existent knowledge, then just as verbatim models for sentence memory are irrelevant, just as syntactically based models appear to be inappropriate, so semantically based accounts may prove to be incomplete and insufficient insofar as they restrict themselves to the explicit meanings specifically embodied in particular sentences. If input information is conflated with pre-existent knowledge, then we shall need a theory of semantic memory which deals with the ways in which cognitive schemata are achieved, stored, modified, and accessed. All this is now vastly beyond our reach, but to mention such requirements may at least lead to some realistic modesty concerning our present achievements.

4 MODELS OF HUMAN MEMORY AND MEMORY FOR SENTENCES

It seems clear that psychologists studying the role of syntactic factors in memory have been far more influenced by formulations stemming from linguistics than by work in psychology proper directed to the development of models of human memory. In part this is so because, as we have argued at length, psycholinguists were really interested in the cognitive representation of syntactic structures, not in problems of memory per se. Further, while there has been much interest in problems of verbal learning and verbal memory, nevertheless, both with regard to personnel and intellectual background, this interest has been separate and distinct from work in psycholinguistics. Indeed, given the scope of recently developed models of human memory, see e.g. Norman (1970), it would appear that even if psycholinguists had actually wished seriously to consider memorial processes, they would have found it very difficult if not impossible to apply these models to the substantive cases in which they were interested. As was pointed out some time ago by Gough & Jenkins (1963) while verbal learning and psycholinguistics "share a concern with the verbal behavior of the human organism", the two areas have developed independently, with differences "in empirical domain and historical development". As Cofer notes, in Dixon & Horton (1968), "verbal learning as an area has its problems and they are largely different from those of psycholinguistics". Work in verbal learning and memory has always been in an externalist, empiricist tradition focused on the effects of environmental contingencies, concerned with the conditions of the formation, retention and transfer of associations, and "the study of language has been but a minor or secondary aspect" of such work. Psycholinguists, on

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the other hand, who are primarily concerned with systematic properties of language, have generally taken an internalist position arguing for the importance of underlying structures as governing the everyday use of language. In fact, the papers in the volume edited by Dixon & Horton are themselves a most impressive testimony to the schism between students of verbal learning and psycholinguists. Additional testimony to this general point, if it were needed, can be found in the different, quite distinct sorts of papers published in the Journal of Verbal Learning and Verbal Behavior, a journal which has as its contributors and audience workers in both of these intellectual traditions, or in the almost complete lack of overlap between the work on "Memory and Verbal Learning" reviewed by Tulving & Madigan (1970), and that surveyed under the title "Psycholinguistics" by Fillenbaum (1971). As a matter of historical fact the concerns of the student of verbal learning and memory and those of the psychologist of language have been, and are different. But what if the psycholinguist studying syntactic factors in memory had wished to make use of current theorizing about human memory, could he have done so in any substantive way? Very likely not. An absolutely basic presupposition of the linguist is that a sentence has internal structure, and most of the work of the psycholinguist can be regarded as constituting an exploration of the ways in which such internal structure affects various performances. But the internal structure of an item, where that item is a sentence, is just what most if not all present day models of human memory do not and cannot cope with. Consider, as a test case, the excellent recent book Models of Human Memory whose editor D. A. Norman justly claims that it contains "a reasonably complete sample of current work on models of human memory", but who is also constrained to point out that these models "do not attempt to describe performance with material that has been organized by the subject... [and] it is quite clear that linguistic performance depends upon the application of rules to the syntactic and semantic structure of language, rather than simple associations among previously encountered items". One or two of the contributors do see some

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relevance of their work to linguistic performance. Thus Morton who is seeking to develop a model for word recognition mentions that some "tentative extensions to more complex language behavior can be found elsewhere". Kintsch claims that the central problem for any model of recall is how organization of the learning material affects recall, asserts further that "meaning provides the most important principle of organization in memory", and does make some attempts to indicate how one might proceed in trying to describe the organization of verbal material in long term memory. But his concern is with the (semantic) relations obtaining among individual words, and this has been the principal concern too of people like Bower (1969) and Mandler (1970) who have shown how category relations obtaining among discrete words may be important factors in recall. But none of this has anything to say directly, or perhaps even indirectly, with regard to the organizational role of syntactic and semantic properties in the memory for sentences. In fact within the Norman book the case of Kintsch is rather atypical, for most of the authors are concerned with memory for individual items or lists of items "that one can reasonably assume are treated as independent units by the memory system. Thus the model will deal with experiments in short term retention and learning of items such as nonsense syllables, paired-associates, and the like" as Bernbach asserts while specifying the scope of his own model and explicitly pointing out that "it is not intended to handle the effects of context or structure (as in remembering sentences)". In this general stance Bernbach is representative of most of the other authors in the book, so we shall give only one additional example. In the course of specifying the restrictions upon the application of a "multitrace strength theory" Wickelgren writes that "the test event should be sufficiently simple that subjects handle it as a unit, making a single absolute or comparative judgment, not a sequence of elementary decisions combined into an overall decision by means of complicated logical reasoning", and goes on to observe that while in principle, at some future time, strength theory should be applicable "to memory for phrases, (and) sentences", no ap-

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plication of this theory to such complex events is now possible. Insofar as the papers in the Norman book are representative of current work on models of human memory, and this does seem to be the case, then in terms of actual practice, if one regards the defining data or the sorts of content for which such models were developed and to which they are applied, and in terms of explicit disclaimers as regards restrictions in scope, these models would appear inapplicable to the substantive problems of principal concern to the psycholinguist. To put it baldly, if the psycholinguist has as one central concern the study of memory for sentences, and if this is precisely what the memory theorists rule out of court as beyond the range of their models, then there is little possibility of substantive contact. Essentially the one psychologist is interested in sentences as analyzable and analyzed objects whose internal structure is of critical importance, and the other psychologist is interested principally in memory for items (or lists of items) constituting independent, atomic units. To the extent that this characterization is even roughly correct we are faced with incommensurables and, in principle, it may be impossible for the psycholinguist to make any use of the theoretical models developed by the student of human memory. With regard to the possibility, or rather the difficulty, of applying formulations based on memory for individual words to problems of sentence memory we should at least mention one possibly crucial difference between word memory and sentence memory. In the case of word memory "the subject stores the information that a particular word has occurred as a member of a list to be memorized. It is not the word itself which is stored, but a reference that the word has occurred .... Words themselves ... are already part of a subject's long term memory" (Kintsch [1970], my italics). Now obviously the above description cannot simply be transposed to the case of sentence memory by substituting "sentence" for "word" in the appropriate places, since a sentence qua sentence constitutes a new semantic object whose meaning is a compositional function of the meanings of the words involved, given the particular syntactic relations holding among them. With the exception of

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cliché expressions one cannot store a sentence by referencing its occurrence since there are indefinitely many possible sentences. Thus in a very basic respect the principles underlying the storage of sentences may have to differ from those involved in word storage. Although work on verbal learning and memory may not have any substantive, theoretical implications for the psycholinguist interested in sentence memory, it seems clear that the latter can draw all sorts of methodological and procedural lessons from such work. Consider a few examples. We have pointed out a number of times that some important properties of the results on sentence memory may be peculiar to the standard intentional learning format employed, that results different in important respects may obtain and do obtain (see e.g. Wanner, 1968; Johnson-Laird & Stevenson, 1970) under incidental conditions. If this is so, then the study of a paper such as that on "Short-term memory and incidental learning" (Postman, 1964) which critically and synoptically reviews and analyzes experimental methods and findings in this area should be of extraordinary value in alerting the psycholinguist to important methodological problems usually ignored. We know that there may be very substantial modality effects such that "auditory presentation produces performance superior to visual presentation for paired-associate and serial recall, recognition, and single-trial free recall" (Tulving & Madigan, 1970). If such modality effects are potentially as significant for theories of memory as Tulving & Madigan claim on the basis of a review of recent research, then they may prove to be of some relevance also with regard to sentence memory. At the very least this should caution against the casual, happenstance choice of input and test modalities, and, for particular cases, require us to determine whether or not given effects are modality specific. Next consider that if one is interested in memorial phenomena then one has to be concerned with effects as a function of the passage of time, and of the events occurring during the time elapsing between original input and the test for memory. Now in fact psycholinguists have been quite casual about this because, as we have stressed, they were characteristically interested in using

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memorial data to get at the cognitive representation of syntactic structures, not as revealing about mnemonic processes. But if one is interested in the latter sort of problem then surely one must systematically explore the effects of varying intervening time and interpolated events. And even if one is only interested in the former sort of problem one must still do this, as we have argued throughout, in order to decompose or factor the results into what is attributable to the object of memory or the representation in memory, and what is attributable to the fate of that representation over time and the vicissitudes of intervening events. Thus, to cite a couple of further examples, Bever & Mehler (see Bever 1968b) have obtained data indicating that for sentences with adverbs and verbal particles the nature of the errors made at recall is rather different for a short term memory paradigm than for a long term one. While one may quarrel with their interpretation of the results as indicating that recall errors tend to reflect the order of terms in the underlying structure for long term memory (30 second interval) but not for short term memory (see Wanner [1968] on this), the important point here is simply that the results do differ as a function of task differences. Bever (1970b) reports that when subjects were required to recall a small set of sentences immediately after briefly inspecting each, the order of recall performance was: actives, passives, pseudopassives. However, when subjects were to recall the same materials "after a relatively long period of time, from an hour to several days" the order of recall performance was: pseudo-passives, actives, passives. Our concern here is not with the fact that each of these orders, in turn, is in close correspondence to a particular sort of syntactic analysis, or in saying which analysis is the 'correct' one, but only to point out that the results do differ as a function of task variables, and that thereforewhether we are interested in problems of cognitive representation or of memorial process these variables need to be investigated.6 Such investigation has hardly begun, as yet. 6

It might be pointed out that results of the sort mentioned above do not require the strong conclusion voiced by Bever (see e.g. Bever 1970b) that "different (and sometimes incompatible) structural hypotheses about sentence

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Let us finally consider or at least raise the question as to whether there may be differences in memorial results as a function of whether a free recall task or a recognition task is used to test memory. Again students of sentence memory have been quite casual in their procedure, often using either sort of task indifferently. Whether recognition and recall involve basically similar psychological processes or whether there are "essential qualitative differences between them" is a matter subject to theoretical controversy. Kintsch (in Norman, 1970) argues for a two-process theory of recognition and recall, noting that while there are a large number of experimental manipulations that affect recognition and recall in similar ways, there are other variables which have a differential effect, e.g. "intention to learn improves recall considerably" suggesting that "efficient recall presupposes some active intentional process", while intention to learn appears largely irrelevant for recognition performance. The basic differences between recall and recognition, as Kintsch phrases it "appears to be that recall involves a search process and recognition does not". If this is so, i.e. if recognition does not involve search in an important way, then variables which facilitate retrieval in recall, such as the structure or organization of the learning material, should have little or no effect on recognition. Kintsch reviews some work which suggests that this expectation is in fact borne out; however, with one possible, remote exception (letter strings structured according to certain transition rules), none of these studies involved as their content syntactically structured materials. At this time there just is not evidence on which to base any firm conclusions as to whether or not syntax as an organizing factor yields similar results, principally because psychologists studying sentence memory have not been concerned to make any systematic contrasts with regard to performance on free recall and recognition tasks, or more specifically

structure are brought out by different sorts of behavioral tasks" since it is quite possible that rather different memorial data may result from the same cognitive representation as a function of what happens to that representation over time, and as a function of differing task requirements.

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to look at verbatim and gist memory with such questions in mind. About all one can do is to point to cases where recall and recognition measures give similar results, and cases where they give divergent results. Thus earlier we mentioned a study by Pompi & Lachman (1967) on "Surrogate processes in short term memory for connected discourse" which obtained parallel results using recall and recognition tasks. However, in a more recent study by Lachman and his associates (Dooling & Lachman, 1971) there were no differences "in the free recall of thematically relevant and irrelevant content words in contrast to very strong effects obtained in recognition". The authors attempt to account for these latter results in terms of differences in the information processing requirements of recognition and recall tasks when dealing with prose, in terms actually quite compatible with those argued by Kintsch above. However, this can hardly qualify as an example of the effects of syntactic organization, but must rather count as a case where semanticthematic properties are involved. In any case, the main observation to make here is that there are very few studies where experimenters have obtained, in parallel, results from a free recall task and from a recognition task, so that, in general, systematic comparisons cannot be made. We shall make only one further point. Kintsch observed that intention to learn improves free recall but is irrelevant to recognition. Does this hold also for the case of sentence memory, and if so are the results similar for verbatim memory and for gist memory? We have very little information on which to base any firm conclusions, but, in terms of Wanner's data and the findings reported by Johnson-Laird & Stevenson, it would appear that the intentional/incidental contrast does make a difference with regard to verbatim recognition memory for surface form but not with regard to recognition memory for semantic information (unfortunately for these cases we do not have any comparison free recall data, but one may suspect that similar results would also have obtained in that case). Quite what the implication of this difference between verbatim and gist recognition memory may be in the context of possible differences between the demands of free

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recall and recognition tasks is not clear. But if in fact it should be the case that here results are very much similar regardless of the technique used to assess memory, with intentional instructions facilitating in regard to verbatim memory but not so, or nowhere near as much so, with regard to gist memory, this should raise questions as to the ways in which sentence materials differ from other materials as objects for memory. Given that memory theorists have not been interested in studying sentential materials and that psycholinguists have not really been interested in problems of memory or the demands made by various sorts of memory tasks, it is not surprising that such problems have hardly been posed, let alone explored. To make the same general point one last time, it seems quite obvious that psycholinguists studying memory for sentences have been excessively casual with regard to many methodological matters, only some of which have been pointed out here, and that knowledge about these may be very important for the proper interpretation of experimental results.

5

CODA

By way of brief summary we can note that this monograph has been principally concerned with arguing two theses in the course of a highly selective review of the relevant literature. First, psychologists who have studied memory for sentences characteristically have not been interested in memorial processes at all, but rather have attempted to use memorial data to provide information about the ways in which syntactic structures are cognitively represented, and because memorial data provide information simultaneously about the object of memory and memory for that object, it would appear that inferences cannot legitimately, unequivocally be made about either. Second, so far as the data go, it appears that sentence memory is semantically rather than syntactically based, with syntactic properties relevant insofar as they are necessary for determining the meaning of a sentence, which, in some form that cannot now be specified, is what is stored in memory. In fact memory may not be for sentences but for knowledge based on or derivable from the information in sentences, as this information interacts with preexistent knowledge. Finally, we have pointed out that since most recent models of human memory have explicitly specified their scope so as to exclude sentential materials there are very good reasons why psycholinguists could not have made use of such models in a substantive way, even if they had really wished to do so. This notwithstanding, work in verbal learning and memory does have methodological implications for the psychologist interested in memory for sentences.

REFERENCES

Anglin, J. M. and G. A. Miller 1968 "The role of phrase structure in the recall of meaningful verbal material", Psychonomic science, 10, 343-44. Bach, E. 1967 "Have and be in English syntax", Language, 43, 462-85. Begg, I. 1971 "Recognition memory for sentence meaning and wording", JVLVB, 10, 176-81. Begg, I. and A. Paivio 1969 "Concreteness and imagery in sentence meaning", JVLVB, 8, 821-27. Bernbach, H. A. 1970 " A multiple-copy model for postperceptual memory", Models of human memory, ed. by D. A. Norman, 103-16 (New York: Academic Press). Bever, T. G. 1968(a) " A survey of some recent work in psycholinguistics", Specification and utilization of a transformational grammar, ed. by W. J. Plath, (= Scientific Report, No. 3) (Contract Nonr A F 19(628)-5127 Air Force Cambridge Research Laboratories). 1968(b) "Associations to stimulus-response theories of language", Verbal behavior and general behavior theory, ed. by T. R. Dixon and D. L. Horton, 478-94 (Englewood Cliffs: Prentice-Hall). 1970(a) "The cognitive basis for linguistic structures", Cognition and the development of language, ed. by J. R. Hayes, 279-362 (New York: Wiley). 1970(b) "The integrated study of language behavior", Biological and social factors in psycholinguistics, ed. by J. Morton, 158-209 (Urbana: University of Illinois Press). Binet, A. and V. Henri 1894 "La mémoire des mots", L'année psychologique, 1, 1-59. Blumenthal, A. L. 1966(a) "Observations with self-embedded sentences", Psychonomic science, 6, 453-54. 1966(b) Discussion of paper by R. J. Wales and J. C. Marshall, Psycholinguistics papers, ed. by J. Lyons and R. Wales, 80-84 (Edinburgh: Edinburgh University Press).

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Downey, R. G. and D. T. Hakes 1968 "Some psychological effects of violating linguistic rules", JVLVB, 7, 158-61. Epstein, W. 1961 "The influence of syntactical structure on learning", American journal of psychology, 74, 80-85. 1969 "Recall of word lists following learning of sentences and of anomalous and random strings", JVLVB, 8, 20-25. Fillenbaum, S. 1966 "Memory for gist: some relevant variables", Language and speech, 9, 217-27. 1968 "Sentence similarity determined by a semantic relation: the learning of 'converses' ", Proceedings of the 76th annual convention of the American Psychological Association, 3, 9-10. 1970 "On the use of memorial techniques to assess syntactic structures", Psychological bulletin, 73, 231-37. 1971 "Psycholinguistics", Annual review of psychology, 22, 251-308. In preparation "Some relations among the uses of 'and', 'or', and ' i f ' " . In preparation "Information amplified: memory for counterfactual conditionals". Fodor, J. 1971 "Current approaches to syntax recognition", The perception of language, ed. by D. L. Horton and J. J. Jenkins, 120-39 (Columbus: Charles E. Merrill Publishing Company). Fodor, J. and M. Garrett 1966 "Some reflections on competence and performance", Psycholinguistics papers, ed. by J. Lyons and R. Wales, 135-154 (Edinburgh: Edinburgh University Press). Fodor, J., M. Garrett, and T. G. Bever 1968 "Some syntactic determinants of sentence complexity. II. Verb structure", Perception andpsychophysics, 3, 453-61. Foss, D. J. and H. S. Cairns 1970 "Some effects of memory limitation upon sentence comprehension and recall", JVLVB, 9, 541-47. Franks, J. J. and J. D. Bransford 1972 "The acquisition of abstract ideas", JVLVB, 11, 311-315. Glucksberg, S. and J. H. Danks 1969 "Grammatical structure and recall: a function of the space in immediate memory or of recall delay?", Perception and psychophysics, 6, 113-17. Goldman-Eisler, F., and M. Cohen 1970 "Is N, P, and PN difficulty a valid criterion of transformational operations?", JVLVB, 9, 161-66. Gomulicki, B. R. 1956 "Recall as an abstractive process", Acta psychologica, 12, 77-94. Gough, P. B. and J. J. Jenkins 1963 "Verbal learning and psycholinguistics", Theories in contemporary

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1964 "The role of semantic and syntactic constraints in the memorization of English sentences", JVLVB, 3, 1-5. Martin, E. and K. H. Roberts 1966 "Grammatical factors in sentence retention", JVLVB, 5, 211-18. 1967 "Sentence length and sentence retention in the free-learning situation", Psychonomic science, 8: 535-36. Martin, E., K. H. Roberts and A. M. Collins 1968 "Short term memory for sentences", JVLVB, 7, 560-66. Matthews, W. A. 1968 "Transformational complexity and short-term recall", Language and speech, 11, 120-28.

Mehler, J. 1963 "Some effects of grammatical transformations on recall of English sentences", JVLVB, 2, 346-51. 1964 "How some sentences are remembered", Unpublished doctoral dissertation, Harvard University. Miller, G. A. 1962 "Some psychological studies of grammar", American psychologist, 17, 748-62. Miller, G. A. and S. Isard 1963 "Some perceptual consequences of linguistic rules", JVLVB, 2, 217-28. 1964 "Free recall of self-embedded English sentences", Information and control, 7, 292-303. Miller, G. A. and D. McNeill 1969 "Psycholinguistics", Handbook of social psychology, 2nd ed., ed. by G. Lindzey and E. Aaronson, 3, 666-794 (Reading: Addison-Wesley). Morton, J. 1970 "A functional model for memory", Models of human memory, ed. by D. A. Norman, 203-54 (New York: Academic Press). Norman, D. A., ed. 1970 Models of human memory (New York: Academic Press). O'Connell, D. C. 1970 "Facilitation of recall by linguistic structure in nonsense strings", Psychological bulletin, 74, 441-52. Paivio, A. 1970 "Imagery and language", Paper presented at a conference on The adaptive function of imagery, Center for Research in Cognition and Affect, City University of New York Graduate Center. 1971 "Imagery and deep structure in the recall of English nominalizations", JVLVB, 10, 1-12. Paul, J. H. 1959 "Studies in remembering: the reproduction of connected and extended verbal material", Psychological issues, 1, No. 2,1-152. Perfetti, C. A. 1969(a) "Sentence retention and the depth hypothesis", JVLVB, 8, 101-04. 1969(b) Lexical density and phrase structure depth as variables in sentence retention, JVLVB, 8, 719-24. Perfetti, C. A. and D. Goodman

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"Memory for sentences and noun phrases of extreme depth", Quarterly journal of experimental psychology, 23, 22-33. Phillips, J. R. and G. A. Miller " A n experimental method to investigate sentence comprehension", Unpublished paper. Polzella, D . J. and N. L. R o h r m a n 1970 "Psychological aspects of transitive verbs", JVLVB, 9, 537-40. Pompi, K . F. and R. Lachman 1967 "Surrogate processes in the short-term retention of connected discourse", Journal of experimental psychology, 75, 143-50. Postman, L. 1964 "Short-term memory and incidental learning", Categories of human learning, ed. by A. W. Melton, 145-201 (New York: Academic Press). Reich, P. A. 1967 "Competence, performance, and relational networks", Paper presented at annual meetings of LSA. Reitman, R . 1969 "Information-processing models, computer simulation, and the psychology of thinking", Approaches to thought, ed. by J. F. Voss, 243-286 (Columbus: Charles E. Merrill Publishing Company). Rohrman, N . L. 1968 " T h e role of syntactic structure in the recall of English nominalizations", JVLVB, 7, 904-12. 1970 " M o r e on the recall of nominalizations", JVLVB, 9, 534-36. Rohrman, N. L. and D. J. Polzella 1968 "Recall of subject nominalizations", Psychonomic science, 12, 376-77. Sachs, J. S. 1967(a) "Recognition memory for syntactic and semantic aspects of connected discourse", Perception andpsychophysics, 2, 437-42. 1967(b) "Recognition of semantic, syntactic and lexical changes", Paper presented at meetings of Psychonomic society. Savin, H. B. and E. Perchonock 1965 "Grammatical structure and the immediate recall of English sentences", JVLVB, 4, 348-53. Schlesinger, I. M. 1968 Sentence structure and the reading process (The Hague: Mouton). Schwartz, D., J. P. Sparkman, and J. Deese 1970 "The process of understanding and judgments of comprehensibility", JVLVB, 9, 87-93. Shepard, R . N. 1967 "Recognition memory for words, sentences and pictures", JVLVB, 6, 156-63. Slamecka, N . 1969 "Recognition of word strings as a function of linguistic violations", Journal of experimental psychology, 79: 377-78. Smith, K. H . and M. D . S. Braine In press "Miniature languages and the problem of language acquisition", The structure and psychology of language, vol. 2, ed. by T. G . Bever

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and W. Weksel (New York: Holt, Rinehart, and Winston). Smith, K. H. and L. E. McMahon 1970 "Understanding order information in sentences: some recent work at Bell Laboratories", Advances in psycholinguistics, ed. by G. B. Flores D'Arcais and W. J. M. Levelt, 253-74 (Amsterdam: North Holland Publishing Company). Stolz, W. S. 1967 "A study of the ability to decode grammatically novel sentences", JVLVB, 6, 867-73. 1969 "Some experiments with queer sentences", Language and speech, 12, 203-19. Tieman, D. G. 1971 "Recognition memory for comparative sentences", Unpublished doctoral dissertation, Stanford University. Tulving, E. and S. A. Madigan 1970 "Memory and verbal learning", Annual review of psychology, 21, 437-84. Wales, R. J. and J. C. Marshall 1966 "The organization of linguistic performance", Psycholinguistics papers, ed. by J. Lyons and R. Wales, 29-80 (Edinburgh: Edinburgh University Press). Wang, M. D. 1970(a) "Influence of linguistic structure on comprehensibility and recognition", Journal of experimental psychology, 85, 83-89. 1970(b) "The role of syntactic complexity as a determiner of comprehensibility", JVLVB, 9, 398-404. Wanner, H. E. 1968 "On remembering, forgetting, and understanding sentences: a study of the deep structure hypothesis", Unpublished doctoral dissertation, Harvard University. Watt, W. C. 1970 "On two hypotheses concerning psycholinguistics", Cognition and development of language, ed. by J. R. Hayes, 137-220 (New York: Wiley). Weisberg, R. W. 1971 "On sentence storage: the influence of syntactic versus semantic factors in intrasentence word associations", JVLVB, 10, 631-644. Wickelgren, W. A. 1970 "Multitrace strength theory", Models of human memory, ed. by D. A. Norman, 65-102 (New York: Academic Press). Wright, P. 1969 "Two studies of the depth hypothesis", British journal of psychology, 60, 63-69. Yngve, V. 1960 "A model and an hypothesis for language structure", Proceedings of the american philosophical society, 104, 444-66.

AUTHOR INDEX

Aaronson, E., 92 Anglin, J. M., 19, 20, 88 Bach, E., 63, 88, 91 Barclay, J. R„ 67, 72-74, 75, 89 Begg, I., 55-56, 57-58, 61, 88 Bernbach, H. A., 80, 88 Bever, T. G„ 4, 19, 40, 45, 47, 83-84, 88, 90, 93 Binet, A., 54, 88 Blumenthal, A. L., 7, 30-31, 32, 33, 34, 35, 44, 45, 88, 89 Boakes, R., 7, 30-31, 35, 89 Bonarius, M., 31-33, 91 Bower, G., 80, 89 Braine, M. D. S., 4, 93 Bransford, J. D., 67, 69, 70, 72-74, 75, 89, 90 Bregman, A. S., 55, 89 Cairns, H. S„ 49-50, 90 Card, S. K„ 61, 65, 89 Chomsky, N„ 2, 40, 89 Clark, E. V., 61, 64, 89 Clark, H. H., 61, 62-63, 64, 65, 89 Clark, M. C., 89 Clifton, C., 25-26, 89 Cofer, C. N„ 78, 89 Cohen, M., 24, 90 Collins, A. M„ 22, 92 Cowan, J., 91 Danks, J. H„ 18, 29, 50, 89, 90 Deese, J., 16, 93 Dixon, T. R., 78, 79, 88, 89 Donaldson, W., 91 Dooling, D. J., 85, 89

Downey, R. G., 16-17, 90 Epstein, W., 3, 29, 50, 90 Fillenbaum, S., 5, 7, 26, 27, 36, 56, 60, 76, 79, 90 Fillmore, C. J., 2 Flores D'Arcais, J. B., 94 Fodor, J., 28, 32, 33, 40, 90 Foss, D. J., 49-50, 90 Franks, J. J., 67, 69, 70, 72-74, 75, 89, 90 Garrett, M„ 28, 32, 40, 90 Gilbert, K„ 47 Glucksberg, S., 29, 50, 90 Goldman-Eisler, F„ 24, 90 Gomulicki, B. R„ 54, 90 Goodman, D., 21, 92 Gough, P. B„ 59, 78, 90 Greenberg, J. H„ 62, 91 Hakes, D. T„ 16-17, 90 Harms, R. T., 91 Hayes, J. R., 88, 94 Henri, V., 54, 88 Horton, D. L., 78, 79, 88, 89, 90 Isard, S„ 14, 43-44, 45, 46, 47, 92 Jakobovits, L. A., 2, 89 Jenkins, J. J., 78, 90 Johnson, N. F., 19-20, 91 Johnson-Laird, P. N., 10, 11, 52, 60, 82, 85, 91 Katz, J. J., 26, 91

96

AUTHOR INDEX

Katz, S„ 70-71, 91 Kintsch, W„ 76, 80, 81, 84, 85, 91 Lachman, R., 54, 85, 89, 93 Lakoff, G., 2 Lamb, S„ 2 Lesgold, A. M„ 36, 89, 91 Levelt, W. J. M„ 31-33, 91, 94 Lindzey, G., 92 Lyons, J., 30, 62, 88, 90, 91, 94 McCawley, J. D„ 2, 14, 91 McMahon, L. E., 64, 93 McNeill, D., 44, 47, 92 Madigan, S. A., 79, 82, 94 Mandler, G., 80, 91 Marks, L. E„ 13-14, 15, 91 Marshall, J. C., 48, 88, 94 Martin, E., 2, 21, 22, 92 Marx, M. H„ 90 Matthews, W. A., 29, 92 Mehler, J., 3, 23-25, 83, 92 Melton, A. W., 93 Miller, G. A., 2-3, 13-14, 15, 19, 20, 23, 43-44, 45, 46, 47, 88, 91, 92, 93 Morton, J., 80, 88, 92 Norman, D. A., 78, 79, 84, 88, 91, 92, 94 O'Connell, D. C., 3, 92 Odom, P., 25-26, 89 Paivio, A., 2, 40-42, 55-56, 61, 88, 92 Paul, J. H„ 54, 92 Perchonock, E., 28, 29, 93 Perfetti, C. A., 21, 23, 92 Phillips, J. R„ 46-47, 93 Plath, W. J., 88 Polzella, D. J., 38, 39, 40, 93 Pompi, K. F., 54, 85, 93 Postal, P. M., 26, 91

Postman, L., 82, 93 Reich, P. A., 2, 93 Reitman, R., 2, 93 Roberts, K. H„ 2, 21, 22, 92 Rohrman, N. L„ 7, 21, 22, 26-40, 41, 42, 93 Rubenstein, H., 47 Sachs, J. S., 54-55, 57, 58, 93 Savin, H. B„ 17, 28, 29, 48, 93 Schlesinger, I. M., 45, 93 Schwartz, D., 16, 93 Sebeok, T. A., v, 89 Shepard, R. N., 57, 93 Slamecka, N., 14, 93 Smith, K. H., 4, 64, 93 Sparkman, J. P., 16, 93 Stafford, R. A., 61, 62-63, 89 Steinberg, D. D., 2, 89 Stevenson, R., 60, 82, 85, 91 Stolz, W. S., 17-18, 44, 45, 47, 48, 94 Strasberg, R., 55, 89 Tieman, D. G., 10-11, 55-56, 66, 71, 94 Tulving, E„ 79, 82, 91, 94 Voss, J. F., 93 Wales, R. J., 30, 48, 88, 90, 94 Wang, M. D„ 15, 16, 18, 94 Wanner, H. E., 3, 5,24, 31, 33, 34-36, 59, 82, 83, 85, 94 Watt, W. C., 3, 40, 94 Weisberg, R. W., 65, 94 Weksel, W„ 4, 93 Wickelgren, W. A., 80, 94 Winzenz, D., 89 Wright, P., 23, 94 Yngve, V., 2, 20-21, 94

SUBJECT INDEX

Anomalous sentences, 13-14, 15, 47 Archimedean technique and short term memory, 17-18, 23, 28-29, 48-50 Comprehension semantic factors in, 15, 16 syntactic factors in, 9, 15, 16, 44 "Converses" learning of, 36 Deep proposition hypothesis, 33-36 Deep structure clue theory, 31-33 Errors as meaning preserving, 25, 52-53, 54-61 as meaning related, 53 Imagery, 2, 10-11, 40-42, 58, 61 Inference strategies, 67, 68, 76 Lexical markings, 62, 64 marked terms, 61-64 unmarked terms, 61-64 Memorial data problems of inference, 5-12, 26-27, 43 Memory criteria for semantic basis of, 52-53 deep structure and, 23-42 deep structure role of prompts in, 30-36 for gist, 11, 56, 57, 70-71, 85, 86 for inferable information, 66-69, 71-74, 75, 76, 87

for semantic situations, 67, 68-69, 72-74, 75 for sentence wording 57, 58, 59 for surrogate structures, 54 form of semantic representation in, 61-66

free recall versus recognition, 84, 85 incidental, 11-12, 15, 59, 60, 82, 85 information gain in, 75-76 intentional 10-12, 82, 85 models of, 4, 6, 10, 78-86, 87 semantic factors in, 1, 4, 23, 33, 36, 63-64, 65, 80, 87 sentence "depth" and, 22-23 short term versus long term, 83 strategies, 10-12 surface structure and, 19-23, 37 syntactic factors in, 1,6,8-9,12-19, 30, 62-63, 65, 78, 79, 87 syntactic malformation and, 12-19 transformational history and, 37-38 verbatim, 10, 11, 60, 70-71, 74, 85, 86 Miniature artificial languages, 3-4 Modality effects, 82 Multidimensional scaling of similarities, 25-26 Multiply self-embedded sentences locus of difficulties in comprehension, 46-48 processing of, 42-51 recall of, 43^4, 48-50 semantic constraints as aids in comprehension of, 45 "subroutine" hypothesis for, 44-45 Nominalizations, 7, 36

98

SUBJECT INDEX

object and recall, 37-42 subject and recall, 37-42 Nonsense strings, 3 Phrase structure models, 2, 20-23 as psycholinguistic accounts, 20-23 Phrase structure violations, 16-18 Pronominalization, 36 Relational inclusiveness hypothesis, 30-31, 33-35 Selection restrictions, 14 violations of, 16-18 Semantic factors in comprehension, see Comprehension, semantic factors Semantic factors in memory, see Memory, semantic factors Semantic relations, 36, 60 Sentence anagrams, 13-14, 15, 17, 18 Sentence "depth", 20-22 Similarity relations among sentences, 24-29

Stimulus, functional versus nominal, 7 Stratificational grammar, 2 Subcategorization violations, 16-18 Syntactic factors in comprehension, see Comprehension, syntactic factors Syntactic factors in memory, see Memory, syntactic factors Syntactic structure and transition error probability, 20 cognitive representation of, 1, 5, 78, 83, 87 Transformational grammar, 2, 20, 22, 24, 26 and psychological accounts, 3 Verbal learning, 78-79 Verbs intransitive, 39-40, 41 lexical representation of, 40, 42 transitive, 39-40, 41

JANUA L I N G U A R U M STUDIA MEMORIAE NICOLAI VAN WIJK DEDICATA Edited by C. H. van Schooneveld SERIES MINOR 42. 44. 45. 47. 49. 50. 51. 52. 54. 55. 56. 58. 59. 60. 62. 63. 64. 65. 66.

Trends in Linguistics. Translated by Muriel Heppell. 1965.260 pp. Gld. 28.— THEODORE M. DRANGE: Type Crossings: Sentential Meaninglessness in the Border Area of Linguistics and Philosophy. 1966. 218 pp. Gld. 29.— WARREN H. FAY: Temporal Sequence in the Perception of Speech. 1966. 126 pp., 29 figs. Gld. 23.— BOWMAN CLARKE: Language and Natural Theology. 1966. 181 pp. Gld. 30.— SAMUEL ABRAHAM and FERENC KIEFER: A Theory of Structural Semantics. 1966. 98 pp., 20 figs. Gld. 16.— ROBERT J. SCHOLES: Phonotactic Grammatically. 1966. 117 pp., many figs. Gld. 20.— HOWARD R. POLLIO: The Structural Basis of Word Association Behavior. 1966. 96 pp., 4 folding tables, 8 pp. graphs, figs. Gld. 18.— JEFFREY ELLIS: Towards and General Comparative Linguistics. 1966. 170 pp. Gld. 26.— RANDOLPH QUIRK and JAN SVARTVIK: Investigating Linguistic Acceptability. 1966. 118 pp., 14 figs., 4 tables. Gld. 20.— THOMAS A. SEBEOK (ED.): Selected Writings of Gyula Laziczius. 1966. 226 pp. Gld. 33.— NOAM CHOMSKY: Topics in the Theory of Generative Grammar. 1966. 96 pp. Gld. 12.— LOUIS G. HELLER and JAMES MACRIS: Parametric Linguistics. 1967. 80 pp., 23 tables. Gld. 14.— JOSEPH H. GREENBERG: Language Universals: With Special Reference to Feature Hierarchies. 1966. 89 pp. Gld. 14.— CHARLES F. HOCKETT: Language, Mathematics, and Linguistics. 1967. 244 pp., some figs. Gld. 28.— B. USPENSKY: Principles of Structural Typology. 1968. 80 pp. Gld. 16.— v. z. PANFILOV: Grammar and Logic. 1968.160 pp. Gld. 18.— JAMES c. MORRISON: Meaning and Truth in Wittgenstein's Tractatus. 1968. 148 pp. Gld. 20.— ROGER L. BROWN: Wilhelm von Humboldt's Conception of Linguistic Relativity. 1967.132 pp. Gld. 20 — EUGENE J. BRIERE: A Psycholinguistic Study of Phonological Interference. 1968. 84 pp. Gld. 14.— MILKA IVIC:

67. 69. 70. 71. 72. 73. 74. 76. 77. 106. 107. 110. 113. 114. 117. 119. 123. 134.

ROBERT L. MILLER: The Linguistic Relativity Principle and New Humboldtian Ethnolinguistics: A History and Appraisal. 1968. 127 pp. Gld. 20 — I. M. SCHLESINGER: Sentence Structure and the Reading Process. 1968. 172 pp. Gld. 22.— A. ORTIZ and E. ZIERER: Set Theory and Linguistics. 1968. 64 pp. Gld. 12.— HANS-HEINRICH LIEB: Communication Complexes and Their Stages. 1968. 140 pp. Gld. 20— ROMAN JAKOBSON: Child Language, Aphasia and Phonological Universals. 1968. 104 pp. Gld. 12.— CHARLES F. HOCKETT: The State of the Art. 1968.124 pp. Gld. 18.— .A. JUILLAND and HANS-HEINRICH LIEB : "Klasse" und "Klassifikation" in der Sprachwissenschaft. 1968. 75 pp. Gld. 14.— URSULA OOMEN: Automatische Syntaktische Analyse. 1968. 84 pp. Gld. 16.— ALDO D. SCAGLIONE: Ars Grammatica. 1970.151 pp. Gld. 18.— HENRIK BIRNBAUM: Problems of Typological and Genetic Linguistics Viewed in a Generative Framework. 1971.132 pp. Gld. 16.— NOAM CHOMSKY: Studies on Semantics in Generative Grammar. 1972. 207 pp. Gld. 24.— MANFRED BIERWISCH: Modern Linguistics. Its Development, Methods and Problems. 1971.105 pp. Gld. 12.— ERHARD AGRICOLA: Semantische Relationen im Text und im System. 1972. 127 pp. Gld. 26.— ROMAN JAKOBSON: Studies on Child Language and Aphasia. 1971. 132 pp. Gld. 16.— D. L. OLMSTED: Out of the Mouth of Babes. 1971. 260 pp. Gld. 36.— HERMAN PARRET: Language and Discourse. 1971. 292 pp. Gld. 32.— JOHN w. OLLER: Coding Information in Natural Languages. 1971. 120 pp. Gld. 20.— ROMAN JAKOBSON : A Bibliography of His Writings. With a Foreword by C. H. Van Schooneveld. 1971. 60 pp. Gld. 10.—

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