Ear differences in simple reaction time: The influence of attentional factors

Simple motor reaction times (right-handed) to tape-recorded consonant-vowel syllables were obtained from 12 subjects under two conditions of monotic stimulation: “expected” presentation (subject informed as to ear of presentation) and “random” presentation (ear of presentation varied randomly). Significantly faster left ear reaction times were obtained in the “expected” condition. The rank order of subjects' standard dichotic listening task scores correlated negatively with reaction time ear differences in the “expected” presentation condition. Results are discussed in terms of existing theories of response lateralization in simple reaction time tasks, and an expanded hypothesis is offered. Specifically, it is suggested that two or more distinct but potentially overlapping mechanisms may be responsible for observed asymmetries in monotic auditory perception. Both an attentional or lateralized motor response bias and an inherent lateralization of function may operate side by side, differentially activated by task demands, mode of stimulus presentation, and nature of stimuli.     

Concurrent validity of the WISC-R factor scores

This study investigated the efficacy of predicting academic achievement as measured by the Wide Range Achievement Test using the factor scores of the Wechsler Intelligence Scale for Children-Revised as potential predictors. Both instruments were administered to 200 school children referred for psychological evaluations. Factor scores for the WISC-R were computed according to equations provided by Gutkin (1978). These factor scores then were regressed in a stepwise manner on the Reading, Spelling, and Arithmetic standard scores from the Wide Range Achievement Test. Stepwise regressions also were performed using the traditional Verbal and Performance IQs as the potential predictors. A comparison was made between the results obtained by use of the factors or the more common scores. The results indicated that the Freedom From Distractibility factor score significantly aided in the prediction of Reading and Spelling achievement and was of primary importance in predicting Arithmetic achievement. When the stepwise results using the different scores were contrasted, the factor scores accounted for appreaciably more variance in Arithmetic than did the traditional Verbal and Performance IQs. Derived regression equations are reported along with a discussion of the interpretability of the Freedom From Distractibility factor.     

Stimulus control of respondent and operant key pecking: A single key procedure

Pigeons' responses to a uniformly illuminated response key were either reinforced on a variable-interval one-minute schedule of reinforcement or extinguished for one-minute periods. When 1.5 second signals were presented at the beginning of each component, so as to differentially predict reinforcement, the pigeons pecked at the signals, at rates higher than rates during the remainder of the component. When the brief signals were not differentially predictive of reinforcement, pecking in their presence decreased to near zero levels. Similar results were obtained with signals based upon colors and upon line orientations. Changes in rates of (unreinforced) pecking occurred during the signal whether pigeons responded differentially during the remainder of the component or not. Experiment II demonstrated that the presence of the signal correlated with extinction was not necessary for pecking to develop at the signal which preceded the component in which responding was intermittently reinforced. The experiments demonstrated a clear dissociation of respondent control from operant control of a response. In addition, operant behavior was shown to be relatively insensitive to differing rates of reinforcement, as compared to the sensitivity of respondent behavior to differing rates of reinforcement produced by the very same operant behavior.     

Context, categorization, and recall: The “change-of-standard” effect

A psycholinguistically based conception of the relation among context, categorization, and memory is tested by examining what happens to people's memory of an object when the object is initially categorized in terms of the context in which it appears, but, when the object is later recalled, this context is no longer salient. Subjects read about the sentencing decisions of a target trial judge in the context of other trial judges who consistently gave either higher sentences or lower sentences than the target judge. As predicted, subjects tended to categorize the target judge as “lenient” in the former, harsh context condition, and as “harsh” in the latter, lenient context condition. A week later, subjects read about the sentencing decisions of some additional judges, and then recalled the sentencing decisions of the target judge they had read about the week before. Across the two sessions, either a harsh, moderate, or lenient category norm for judges' sentencing decisions was established by having subjects read about decisions that involved either high, medium, or low sentences, respectively. The results indicated that subjects recalled the target judge's decisions by interpreting their prior categorization of his behavior in terms of the category norm established across the two sessions rather than the original context. Thus, subjects who were exposed to the same target in the same circumstances, and initially categorized the target in the same way, nevertheless remembered his behavior differently if their category norm was different at the moment of recall. Other types of “change of standard” and their implications for human judgment and memory are discussed.     

Neuropsychological assessment of learning disabilities: a discriminant analysis

The neuropsychological test scores of 23 learning disabled children were compared with those of a matched population of normal children in the 9-1 to 13-1 age range. All children were administered the Wechsler Intelligence Scale for Children-Revised (WISC-R), a dichotic listening task involving both free and directed recall conditions, a handedness inventory, the Tactile Performance Test and the Category Test from the Halstead-Reitan Neuropsychological Test Battery. A multivariate analysis of variance resulted in a significant separation between groups (p less than .001) using these procedures. A stepwise discriminant function analysis revealed that both of the directed dichotic tasks contributed the most of all 13 measures to the significant group separation. In addition, other cognitive tasks found to discriminate normal from learning disabled children include general verbal processes, concept formation, and tactile memory. These findings suggest that the directed dichotic listening procedure and the WISC-R Verbal IQ measure are reasonably valuable clinical tools in the classification of learning disabilities.     

Reaction times of younger and older men and temporal contingencies of reinforcement

Influences of extended training and temporal contingencies on reaction time were studied in relation to developmental differences. Older and younger men were trained on a chained schedule in which completion of a variable interval produced a terminal link in which reaction time was measured. The reaction-time procedure involved a conditional discrimination with matching to sample in one component and oddity matching in the other. During baseline training, no time limit was placed on the response to the discrimination choice stimuli. Subsequently, increasingly severe time limits were imposed over a series of sessions. Older and younger men showed increased speeds (decreased reaction times) when temporal contingencies were imposed, and these changes were maintained during post-training baseline sessions when there was unlimited time in which to respond. The younger men generally responded faster than the older ones, and age differences were not appreciably reduced during the course of the experiment. The results indicated the feasibility of studying reaction time in human subjects using operant procedures analogous to those developed for the study of nonverbal organisms.     

Preferences for skill versus chance-determined activities: The influence of gender and task sex-typing

Three experiments tested the hypothesis that skill-chance activity preference by men and women is moderated by task sex relatedness. Men and women (total N = 368) opted to perform either skill or chance versions of masculine and feminine tasks, and then provided ratings of performance expectancy, importance of success, and perceptions of task characteristics. Results support the conclusion that men do not prefer skill and women chance as had been found previously, but rather that while men's skill preferences are higher than women's on a masculine taks, women prefer skill more than do men on a feminine task. Skill-chance preferences were primarily a function of the expectancy of success on skill tasks.     

Lesions of the basal ganglia, thalamus, and deep white matter: Differential effects on language functions

Forty-five patients with unilateral demarcated vascular lesions in the basal ganglia, the thalamus and the deep white matter were investigated with an "aphasia battery." Patients with basal ganglia lesions performed worse than both other groups in tests of articulation, syntax, and lexical functions. The deficit of patients with basal ganglia lesions on all expressive language modalities was lateralized to the left hemisphere. Patients with left thalamic lesions showed impairments of speech fluency and in the Token Test. Patients with white matter lesions alone showed no effect of laterality in tests of language functions. The results are discussed on the basis of a recent theory of the participation of the deep nuclei in language processing.     

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.