The use of the psychological stress evaluator with stutterers

A lie detection instrument, the Psychological Stress Evaluator, has been reported by the manufacturer as being capable of quantifying changes in the degree of “stress” as reflected by a subject's voice. Speech pathologists might consider the use of the instrument in clinical and research activities concerning the stutterer's emotional (stress) reaction to stuttering.To test the validity of the instrument, four stutterers and four normal speakers were recorded while making consecutive telephone calls. Randomized recordings were analyzed by a company trained technical to determine the degree of stress for each speech sample.Results indicated that both groups had a significant reduction of stress from the first to the fourth telephone call. However, the groups did not differ in the degree of stress during the ordered series of calls. Due to the inability of the Psychological Stress Evaluator to differentiate between the groups, the validity of the instruments is questioned.     

Essential independence and likelihood-based ability estimation for polytomous items

A definition ofessential independence is proposed for sequences of polytomous items. For items satisfying the reasonable assumption that the expected amount of credit awarded increases with examinee ability, we develop a theory ofessential unidimensionality which closely parallels that of Stout. Essentially unidimensional item sequences can be shown to have a unique (up to change-of-scale) dominant underlying trait, which can be consistently estimated by a monotone transformation of the sum of the item scores. In more general polytomous-response latent trait models (with or without ordered responses), anM-estimator based upon maximum likelihood may be shown to be consistent for under essentially unidimensional violations of local independence and a variety of monotonicity/identifiability conditions. A rigorous proof of this fact is given, and the standard error of the estimator is explored. These results suggest that ability estimation methods that rely on the summation form of the log likelihood under local independence should generally be robust under essential independence, but standard errors may vary greatly from what is usually expected, depending on the degree of departure from local independence. An index of departure from local independence is also proposed.This work was supported in part by Office of Naval Research Grant N00014-87-K-0277 and National Science Foundation Grant NSF-DMS-88-02556. The author is grateful to William F. Stout for many helpful comments, and to an anonymous reviewer for raising the questions addressed in section 2. A preliminary version of section 6 appeared in the author's Ph.D. thesis.     

Lithium-mediated disruptions of latent inhibition: Overshadowing by the unconditioned stimulus in flavor conditioning

In a series of experiments, the ability of a single lithium preexposure to disrupt CS effectiveness was assessed using a latent inhibition procedure. Lithium preexposure administered proximal (90 min) to a saccharin familiarization trial reduced latent inhibition whereas a similar administration more distal (360 min) to flavor familiarization failed to do so. Additional experiments demonstrated that this socalled “US overshadowing” effect was not attributable to sensitization (Experiment 2), excitatory backward conditioning (Experiment 3), or state dependency (Experiment 4). The implications of US overshadowing for proximal US-preexposure effects are discussed.     

Syntactic and semantic processes in aphasic deficits: The availability of prepositions

The availability of a specific category of closed class items (prepositions) was examined in Broca's and Wernicke's aphasia. The role of prepositions was varied (syntactic/semantic) in two tasks: one requiring production of prepositions and the other acceptability judgments. Overall, it was easier to perform the acceptability task than to produce the target item. In the judgment task, Wernicke's aphasics more accurately determined the acceptability of prepositions in their syntactic role than in their semantic role, but Broca's aphasics showed no such difference. In the production task, Wernicke's aphasics again were more likely to produce prepositions which were in a primarily syntactic role. Broca's aphasics, however, failed to produce such syntactically based prepositions. The results suggest that the availability of a given closed class vocabulary form is not merely a function of its class membership but also of its functional role, and this fact serves to distinguish aspects of Broca's and Wernicke's aphasics' deficit.     

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.     

Cerebral lateralization in individuals diagnosed as autistic in early childhood

Early infantile autism was found to be associated with an atypical pattern of cerebral lateralization. Based on EEG measures of hemispheric activation during cognitive processing, it was found that 7 of the 10 autistic individuals tested showed a pattern of hemispheric specialization rarely seen in the normal population; namely, a “reversal” in lateralization reflective of a lack of left-hemisphere specialization for linguistic functions. Furthermore, the autistic individuals' pattern of cognitive strengths and weakness is suggestive of a selective impairment of the left cerebral hemisphere.     

Evidence for the self as an imaginal prototype

This study investigated recognition memory of self-photographs which had been previously rated by subjects for their degree of reference to an imaginal prototype of “real self.” The number of false alarms to NEW photographs was found to increase with degree of self-reference to the imaginal prototype with the exception of photographs rated highest in self-reference. Females were reliably superior to males in self-recognition. Males and females also differed in nonverbal behaviors reflecting differences in their image of real self. Results were interpreted as supporting an hypothesis that the self functions as a cognitive prototype which has both imaginal and verbal characteristics.     

Antecedents of fluent and dysfluent oral reading: A descriptive analysis

Utilizing the method of repeated observations of a single subject, 18 oral reading samples were obtained from a fluent male child. Observations were made when the child was 5.6 to 6.1 yr of age. The reading material contained varying amounts of words neither understood nor produced by the child. Taped samples were analyzed for antecedents and consequences of fluent and dysfluent events, and extraneous verbal and nonverbal stimulus-response sequences. The analysis revealed the presence of five antecedents of dysfluencies: (1) poor lexical control, (2) competing stimulus-response sequences, (3) intraverbal break, (4) poor prosodic control, and (5) unusually strong intraverbal control. The results also suggested that fluency may be a function of appropriate, sequential, discriminative, stimulus control, adequate intraverbal and prosodic control in the absence of overbearing intraverbal control and interfering stimulus-response sequences.