Hierarchical coding in speech timing

The analysis of syllable and pause durations in speech production can provide information about the properties of a speaker's grammatical code. The present study was conducted to reveal aspects of this code by analyzing syllable and pause durations in structurally ambiguous sentences. In Experiments 1–6, acoustical measurements were made for a key syllabic segment and a following pause for 10 or more speakers. Each of six structural ambiguities, previously unrelated, involved a grammatical relation between the constituent following the pause and one of two possible constituents preceding the pause. The results showed lengthening of the syllabic segments and pauses for the reading in which the constituent following the pause was hierarchically dominated by the higher of the two possible preceding constituents in a syntactic representation. The effects were also observed, to a lesser extent, when the structurally ambiguous sentences were embedded in disambiguating paragraph contexts (Experiment 7). The results show that a single hierarchical principle can provide a unified account of speech timing effects for a number of otherwise unrelated ambiguities. This principle is superior to a linear alternative and provides specific inferences about hierarchical relations among syntactic constituents in speech coding.     

The processing of fundamental frequency in a dichotic matching task

The temporal characteristics of auditory memory were investigated using a reaction time paradigm. The study attempted to determine whether or not there are functionally distinct left and right hemisphere components of auditory memory with different capacities for the retention of nonlinguistic information, such as fundamental frequency, over the course of several seconds. The results indicated that fundamental frequency information in auditory memory remains substantially unchanged over the course of 2 sec. No evidence was found for the existence of separate left and right hemisphere components of auditory memory with different temporal characteristics. The implications of this finding for the organization of auditory memory in the brain are discussed.     

Artificial intelligence,language, and the study of knowledge

This paper studies the relationship of Artificial Intelligence to the study of language and the representation of the underlying knowledge which supports the comprehension process. It develops the view that intelligence is based on the ability to use large amounts of diverse kinds of knowledge in procedural ways, rather than on the possession of a few general and uniform principles. The paper also provides a unifying thread to a variety of recent approaches to natural language comprehension. We conclude with a brief discussion of how Artificial Intelligence may have a radical impact on education if the principles which it utilizes to explore the representation and use of knowledge are made available to the student to use in his own learning experiences.     

Against definitions

Definitional accounts of language structure are explored in this paper. Several classes of arguments for definitions are reviewed; those which connect to: classical theories of reference, theories of informal validity, theories of sentence comprehension, and theories of concept learning. We suggest that, for each of these areas, accounts which rely upon definition are, in fact, not to be preferred on evidential grounds to plausible non-definitional alternatives. We also present a series of experimental observations bearing on one of these areas — that of sentence comprehension. We show that one widely cited class of examples of definitional structures — that of “causative verbs” — fails to affect subject judgements of those relations among the words of causative sentences which depend upon the putative definitional structures. Such subject judgements are independently demonstrated to be sensitive to structural relations of comparable type for other linguistically non-problematic types.     

Formal models of language learning

Research is reviewed that addresses itself to human language learning by developing precise, mechanistic models that are capable in principle of acquiring languages on the basis of exposure to linguistic data. Such research includes theorems on language learnability from mathematical linguistics, computer models of language acquisition from cognitive simulation and artificial intelligence, and models of transformational grammar acquisition from theoretical linguistics. It is argued that such research bears strongly on major issues in developmental psycholinguistics, in particular, nativism and empiricism, the role of semantics and pragmatics in language learning, cognitive development, and the importance of the simplified speech addressed to children.     

Perceptual and conceptual organization of facial emotions: Hemispheric differences

Patients with lesions to either the right or left hemisphere and control subjects were asked to judge the similarity of pairs of photographs of a person displaying different emotions, and of pairs of emotion words. The results were submitted to a multidimensional scaling analysis. Right-hemisphere-damaged subjects were found to be more impaired at perceiving facial emotions than were left-hemisphere-damaged subjects or controls, and this impairment was not confined to the perception of a subset of facial emotions nor to judging emotional valence (Pleasantness versus Unpleasantness). Rather, subtle impairments in perceiving a wide range of facial emotions were found, mostly concerning differentiation of the Positive-Negative and Attention-Rejection dimensions, and concerning the strategies the subjects used to make their judgments. The right-hemisphere-damaged subjects performed comparably to controls in their ratings of emotion words, suggesting that their ability to conceptualize emotional states was intact and that their impairment was strictly in the perception of emotion.     

The efficacy of progressive relaxation in systematic desensitization and a proposal for an alternative competitive response--the relaxation response.

The theoretical basis of systematic desensitization is reciprocal inhibition in which an alternative, competitive response to anxiety is conditioned to arousal-producing, phobic stimuli. Abbreviated training in progressive relaxation is believed to serve as a competitive response to anxiety by decreasing autonomic nervous system activity. However, physiologic studies of progressive relaxation have not substantiated that its practice is associated with such decreased autonomic activity. Consequently, the use of progressive relaxation has been a confounding factor in the determination of the function of reciprocal inhibition in systematic desensitization. To confirm and refine the theoretical constructs of reciprocal inhibition, it is necessary to test the effects of a response which is competitive to the anxiety response. Such a response may be the relaxation response which is characterized by physiologic changes consistent with decreased autonomic nervous system activity. Derived from meditational practices, techniques which ehcit the relaxation response incorporate the element of focused attention which has been implicated as a critical factor in systematic desensitization. Thus, the use of the relaxation response should be a more appropriate method than progressive relaxation if the therapeutic usefulness of systematic desensitization is indeed due to reciprocal inhibition.     

The effect of grammatical complexity upon disfluency behavior of nonstuttering preschool children

The effect of grammatical complexity on the disfluency behavior of nonstuttering 3- and 4-yr-old children was examined. Thirty normal children repeated after the examiner 30 sentences which represented six different grammatical constructions. These grammatical constructions represented a range of grammatical complexity.The total number of disfluencies that occurred in each sentence type was compared. The occurrence of specific disfluency categories in each sentence type was also examined. Subjects produced significantly more disfluencies on passive sentences than on any other sentence type. The passive elicited significantly more interjections, word repetitions, and revisions than the other sentence types.The effect of sentence type on imitation performance was also examined. The auxiliary Have and negative sentence types elicited significantly more imitation errors than other sentence types. Initiation and fluency performance for individual subjects were also examined.The results of the present investigation suggest that when grammatical complexity is controlled, the relationship between disfluencies and grammatical complexity is complicated. When grammatical constructions were relatively difficult for children, complexity affected the occurrence of disfluencies. However, factors other than grammatical complexity affect the occurrence of disfluencies in pre-school children.     

The functional equivalence of mental images and errors of movement.

Four experiments are reported demonstrating that mental images are functionally equivalent to physical errors of movement in producing changes in visual-motor coordination, at both central and peripheral levels of the visual-motor system. In the first experiment, subjects in one condition pointed at a target seen through laterally displacing prisms and were instructed to imagine pointing errors identical to those recorded previously for subjects in a separate condition who actually observed their pointing errors. Changes in pointing accuracy during adaptation procedures and visual-motor aftereffects following these procedures for subjects who imagined their errors were proportional to visual-motor shifts and aftereffects for subjects who observed their errors. In the second experiment, these same imagery instructions resulted in identical pointing shifts and aftereffects even in the case where prisms did not displace the target. The third experiment showed that when subjects believe that their mental images of pointing errors do not correspond to their actual pointing errors, pointing aftereffects result that are characteristic of the processing of error information at peripheral, but not central, levels of the visual motor system. The final experiment showed that when subjects do believe that their images of pointing errors correspond to actual pointing errors, but imagine the pointing movement itself in addition to their errors, pointing aftereffects result that are characteristic of the processing of error information at central, but not peripheral, levels of the visual-motor system. Contributions to visual-motor aftereffects from these two levels appear to be additive. Another significant result was that, in the imagery feedback conditions of each experiment, subjects who gave high ratings of vividness to their mental imagery showed the greatest magnitude of pointing aftereffects. These findings establish that mental images for errors of movement can produce stable visual-motor changes that cannot be accounted for simply by subjects' expectations regarding the actual consequences of their actions.     

The onset of stuttering following drug overdose

Recently, some attention has been focused on acquired stuttering, disfluencies that begin in adulthood. The nature of acquired stuttering differs in several respects from developmental stuttering. A case of acquired stuttering following drug overdose is presented and contrasted with previously reported cases. The case is noteworthy in that, while many characteristics of acquired stuttering are evidenced, several symptoms associated with developmental stuttering are also observed. The findings are discussed in terms of a possible link between developmental and acquired forms of stuttering.     

The effect of punishment and reinforcement procedures on a stutterer's factor II avoidance response

The purpose of this clinical experiment was to investigate the manipulability of a Factor II avoidance response (arm movement). The substantive hypothesis under test was that its suppression would be enhanced by repeated punishment sessions. During the first of nine therapy sessions response-contingent negative stimulation was not delivered. In the next five, after a base-rate period, “wrong” was made consequent upon the target response. In each of these sessions the suppression of arm movement was apparent. However, the magnitude of the suppression decreased from session to session. Evidently, the continued use of punishment did not enhance suppression. Because of this finding procedural changes were introduced in the next three therapy sessions. Verbal praise was added as a consequence of increasingly stringent omission criteria and three consecutive units of praise led to time-out from the reportedly fatiguing task of continuous speech. A marked reduction and then complete extinction resulted. Moreover, learning was evidenced since the frequency of arm movement lessened in the base-rate period of each session.     

Further observations on the nature of prosopagnosia

Two new cases of prosopagnosia are described and compared with pertinent clinical material from the English language literature. The interpretation of this disorder most compatible with the clinical data appears to us to be that there is an underspecification of visuoperceptive information preventing both the formation of significant face images and the retrieval of well-known face memoranda existing within a relatively intact visual remote memory store. Failure of formation of immediate memoranda of similarly complex visual images is also commonly observed but does not seem to be a requirement for the symptom of prosopagnosia. Conceptualizing this abnormality as simply a material specific visual agnosia of images beyond the classifier level would still appear to be acceptable if less informative.     

The effect of punishment on a factor I stuttering behavior

On each of five days the subject of this experiment read aloud different material during an 18-min A₁ (base rate), B (experimental), and A₂ (extinction) period. No stimulation was delivered during the first three days. On the fourth day, the nonsense word “norg” was presented noncontingently during the experimental period. There was no statistically significant difference between the A₁ and B periods on any of these four days. On day five, “wrong” was made contingent on Factor I prolongations during the experimental period. As a result, there was a statistically significant increase in their frequency. When the response consequence was removed in the A₂ priod, there was a reliable reduction in prolongations and the frequency closely approximated that found in the A₁ period. These data suggest that response-contingent negative stimulation is contraindicated as a clinical tactic for use with Factor I prolongations. It not only failed to suppress them, it increased their frequency.     

Reading abilities of school-age stutterers

The reading abilities of 20 school-age stutterers and their matched normally fluent controls were assessed by means of the Woodcock Reading Mastery Tests. Results indicate that the reading abilities of school-age stutterers are not significantly different from those of school-age normals. Similarly, knowing whether a subject was classified as a stutterer or normally fluent speaker was of minimal assistance in predicting the subject's reading performance. These findings suggest that school-age stutterers' reading abilities are within normal limits. An individual stutterer, just like an individual normally fluent speaker, may exhibit “reading problems”; however, caution should be employed in extrapolating from one individual stutterer's reading performance to the reading abilities of all stutterers.     

Psychological studies of children who have cancer

Increasingly, more optimistic prognoses for children who have cancer have led investigators to study the adjustment reactions of children who survive this traumatic experience. There is considerable evidence that the experience of having cancer, receiving prolonged and often painful treatment, and the uncertain condition of cancer survivorship have profound emotional effects on children. The characteristic features of the psychological impact of cancer are the experience of continuing uncertainty in a life-threatening crisis and the resultant search for meaning. Studies are beginning to find that even very young children actively struggle to organize and make sence of this experience.