Central auditory processing. V. Ear advantages for acoustic stimuli in baboons

Four baboons (Papio cynocephalus) were tested using food as reward for ear advantages in the monaural discrimination of pure tones, three-tone musical chords, synthetically constructed consonant-vowels, and vowels. All four animals showed highly significant and reproducible ear advantages for each class of acoustic stimulus with marked individual differences in the direction of their ear asymmetry. The results obtained in these experiments represent the first evidence of ear asymmetries for different classes of acoustic stimuli in a nonhuman species. Further, the ear advantages found in these animals under monaural conditions resemble those obtained with dichotic presentation in human subjects and thus suggest that the baboon may be a valuable model of central auditory processing of various types of acoustic stimuli in man.     

Written spelling deficit of Broca''s aphasics

The purpose of this study was to investigate the nature of the written spelling deficit manifested by Broca's aphasics. Four spelling tests were given to eight Broca's aphasic patients. Analysis of misspelling errors led the investigators to conclude that Broca's aphasics do not spell phonically, but rather adhere exclusively to a visual/orthographic strategy. Possible cognitive deficits underlying the spelling problem are identified. The written spelling deficit is related to other features of the syndrome of Broca's aphasia, and finally, speculations are offered concerning the neurological substrate of written spelling in Broca's aphasic patients.     

Voice onset time production and perception in apraxic subjects

This study explored the relationship between the perception and production of voice onset time (VOT) in apraxic subjects. Spectrograms of the words, “bees” and “peas” spoken by apraxic subjects were acoustically analyzed to obtain a measure of VOT. The subjects also identified the initial cognate (“b” or “p”) from synthetically generated speech spanning a voiced to voiceless time continuum. The results suggest that apraxic subjects have production as well as perceptual errors in the voicing feature but no significant relationship was found between the two measures.     

Central auditory processing : III. The “cocktail party” effect and anterior temporal lobectomy

The capacity to selectively attend to only one of multiple, spatially separated, simultaneous sound sources—the “cocktail party” effect—was evaluated in normal subjects and in those with anterior temporal lobectomy using common environmental sounds. A significant deficit in this capacity was observed for those stimuli located on the side of space contralateral to the lobectomy, a finding consistent with the hypothesis that within each anterior temporal lobe is a mechanism that is normally capable of enhancing the perceptual salience of one acoustic stimulus on the opposite side of space, when other sound sources are present on that side. Damage to this mechanism also appears to be associated with a deficit of spatial localization for sounds contralateral to the lesion.     

Aphasia following a right thalamic hemorrhage

A left-handed patient with a right thalamic hemorrhage and disordered speech is described. Sequential examinations and aphasia testing were done during a 1-year follow-up period and the results are reported. This case supports those authors who have described characteristics they feel are helpful in diagnosing disordered speech associated with thalamic lesions. Paucity of speech, reduced voice volume, anomia, some paraphasia, and severe dysgraphia were present, but comprehension and repetition were relatively preserved. She showed modest improvement with time. This case also confirms that thalamic involvement in speech is a dominant, rather than a specifically left hemispheric function.     

An awareness approach to the covert symptoms of stuttering

Speech-language clinicians working with the confirmed stuttering client are often faced with the clinical management of the covert symptoms of stuttering in addition to the more observable and measurable overt symptoms. The authors report the successful use of awareness techniques to exaggerate the subjective experience of these covert symptoms and encourage the use of these techniques as an adjunct to the counseling and desensitization procedures traditionally employed. A transcribed clinical management session in which several awareness techniques are used to aid the client in an introspective examination of “anticipation of stuttering,” is analyzed in order to reach some specific recommendations for using awareness techniques in the clinical management of the covert symptoms of stuttering.     

The ecological approach to perceiving as a foundation for understanding the development of knowing in infancy

The ecological thesis of direct realism is used as a framework for examining the development of knowing in human infancy. When information for perceiving is defined ecologically (i.e., relative to the situational context and to the physical dimensions, capabilities, and needs of the perceiver), knowing need not be construed as the act of using representations to give meaning to acts or percepts. Knowing, alternatively, is the act of noticing affordances, situation and perceiverspecific meanings of objects, according to their value to the perceiver for achieving specific goals. Changes with development in infant sensorimotor functioning may, in this view, be explained by a process of increasing economy in noticing potentially available affordances, rather than a process of constructing a representational system for making present something not present. Studies of three infant skills widely attributed to the onset of representation are examined with regard to this ecological thesis. Results indicate that the noticing of affordances is critically involved in each of these skills.     

Creating and criticizing theory

F. W. Vondracek, R. M. Lerner, and J. E. Schulenberg (Journal of Vocational Behavior, 1983, 23, 179–202) criticize the vocational literature for failing to “follow acceptable scientific procedures for building a theory” and for failing to attend to important methodological and substantive developments. It is argued here that no single acceptable process for creating theory exists and three strategies useful for developing a theory are illustrated: immerse yourself in data, pick a specific set of results to explain, and try to resolve inconsistencies in the literature. Three criteria for evaluating theories and criticisms of them are discussed: comprehensiveness (content value), accuracy (truth value), and clarity (form). The paper by Vondracek et al. is examined from this perspective and is shown to lack the specificity, clarity, and accuracy necessary to be an effective guide to better vocational research or theory.     

Verbal self-correction behaviors of fluent and nonfluent aphasic subjects

This investigation examined the use of six explicitly defined verbal self-correction behaviors by fluent and nonfluent aphasic subjects of high and low verbal ability, and by subjects further classified into six groups according to type of aphasia (Broca's, Anomic, Wernicke's etc.). Aphasic groups, on the average, generated some type of verbal self-correction effort on more than half of their initially erroneous responses, and the proportions of these efforts did not differ between aphasic patient groups. Significant differences in self-correction success were found, however, between groups classified according to fluency and severity, as well as among the six groups based on type of aphasia. In the former case, distinctions in self-correction skill favored high-verbal-ability groups regardless of fluency classification. In the latter instance, the subgroups typically formed by less severely impaired patients (Anomic and Broca's) had significantly higher proportions of successful self-correction behaviors than those comprised of individuals with more severe involvement (Wernicke's and Broca's plus severely limiting apraxia of speech). Between-group differences for specific types of self-correction behaviors occurred rarely, but those which were found could be related to characteristics of the particular aphasic groups under consideration. Verbal self-correction behavior is discussed as a behavioral reaction to an erroneous response or dissatisfaction with the quality of an intended response. These behaviors are viewed as indicators of the intactness of an aphasic individual's self-monitoring system, and of his tolerance for responses that are qualitatively limited by his verbal deficits.     

Aphasics' selective deficits in appreciating grammatical agreements

This study attempted to dissociate in aphasic patients different aspects of grammatical capacity. Subjects were asked to evaluate sentences containing violations of agreements between pronouns and verbs. Agreements which are considered primarily structural in nature were violated (e.g., a surface object case like “them” placed in a surface subject sentential slot) while other violated agreements seemed to involve both structural and semantic information (e.g., lack of agreement between a pronoun and a verb in terms of the number of people performing the act). These violations were couched in one of three types of sentential frames which varied in terms of syntactic complexity (e.g., active declarative vs. passive syntactic voices). The results revealed that Broca's aphasics found agreement violations difficult to detect in complex syntactic frames. They were quite successful at detecting even violations of the largely structural “case” type of agreement, however, when couched in simpler syntactic frames. Fluent aphasics encountered more difficulty detecting violations of agreements involving both semantic and structural information than agreements which were primarily structural in nature, that is, regardless of the syntactic frame. These unique performance profiles suggest that Broca's aphasics may be agrammatic only with respect to certain aspects of a sentence's structure, and that fluent aphasics may also experience some selective—but different—grammatical deficits.