Transfer of reaction inhibition

A serious challenge to Hull's (1943) theory of reminiscence and intertrial-interval effects is posed by the current contention that reactive inhibition (In) must be task-specific since it does not seem to transfer from one task to another. This notion was examined within the framework of a practice-rest paradigm in which three control groups were given 20 1-min trials on a principal task with intertrial intervals of 0, 5, and 70 sec, respectively, while two experimental groups practiced alternately on the principal task and a secondary task known to produce evidence for I(R). The two secondary tasks varied in their similarities to the principal task. Additional control groups were used to assess the magnitude of habit transfer effects. The total sample consisted of 70 males and 70 females whose modal age was 18 yr. With habit transfer effects controlled, results showed clearly that work effects transferred from the alternate tasks to the main task without regard for differences in similarity. Thus, the task-specificity hypothesis was not supported.     

Nonverbal assessment of interpersonal affect.

Two nonverbal methods for assessing degree of interpersonal attraction were explored. Twenty children ranging from 11 to 13 years of age were asked to select two liked and two disliked classmates of the same sex. On four different trials, subjects selected one geometric block to represent themselves and one to represent a pre-selected classmate, then placed the figures on a ruled board. Distance between objects was measured and found to be significantly related to degree of peer liking. In addition, subjects were asked to draw each of the four peers. The human figure drawings were rated for total pictorial detail which was found to vary strongly across magnitude of liking for female subjects, and for parts integration which was found to vary with degree of peer liking for both sexes. The degree of rated positive affective tone of drawings was also found to increase with liking. Implications for the use of these two interpersonal assessment techniques in clinical practice were discussed.     

Handedness and stuttering: A dead horse?

A handedness questionnaire was administered to 446 stutterers and a control group. No significant male/female or stutterer/control effects were found, although both males and stutterers tended to be less right handed. The slight sex effect in handedness is consistent with previously reported studies and with cerebral structural and functional asymmetries.     

Brain perfusion and neuropsychological test scores: A correlation study in aphasics

In 26 patients suffering from the pure types of aphasias (11 total, 6 motoric, 5 sensory, and 5 amnesic), hemispheric and regional cerebral blood flow were measured and the flow values were correlated with psychological test scores including Wechsler Adult Intelligence Scale (WAIS), Token Test, Benton Test, and word fluency tests. With respect to the flow values, an overall difference between the groups of aphasics was proved by analysis of variance [regional cerebral blood flow (rCBF): F(3,22) = 13.77, p < .001]. The location of mainly impaired brain perfusion was not always confined to the centers within the speech area expected in view of the clinical disturbance, but most patients had neurologic deficits in addition to their aphasia. High correlations were found between the rCBF values within ischemic foci and WAIS subtests, as well as Token Test and word fluency tests. The correlation coefficients calculated between hemispheric flow and the psychological data indicated, in many instances, the same dependency, but did not attain the high statistical significance obtained with the regional values. The results show dependencies of several aspects of mental function upon cerebral perfusion and provide information for possible mechanisms responsible for the disturbance of nonverbal intelligence in aphasics.     

Text comprehension in aphasia

The semantic and pragmatic strategies in the comprehension of spoken texts are investigated in four subgroups of aphasic patients and in normal and brain-damaged controls. Short texts of similar linguistic structure were read to the subjects, who were required to choose the picture, from a multiple choice set of five, that was appropriate to the story. Besides a picture showing the main event of the story, one picture depicted the literal sense of a metaphorical comment, and the others misrepresented semantic functions expressed in the text. With respect to these types of responses, both aphasics and controls exhibited the same pattern of reaction. It is concluded that the redundancy of texts makes up for the difficulties aphasics have in comprehending isolated words and sentences.     

Conceptual encoding and locus of the Stroop effect

Subjects reacted to coloured season and month names by naming the season associated with the print colour of the word, or by naming the season opposite to the one associated with the print colour. Reactions were facilitated in both tasks when the word on the display named the season associated with the colour or was a month belonging to that season. Opposite season naming was not facilitated when the word named the response which the subject made. A comparable effect of print colour was found when subjects reacted to season names by naming the colour associated with the name, or with its opposite. These results suggest that Stroop congruity and interference effects occur during conceptual encoding, and not during response production.     

A simple technique for correlating film and EMG in locomotion studies

Two recurring problems hampering investigations of muscular activity patterns during locomotion are electrical “noise” and movement artifact in the electromyographic (EMG) signal and proper synchronization of behavioral events to the EMG. A relatively simple technique for achieving these ends is presented. Vigorous locomotor movements of unrestrained animals are recorded on 16-mm film and synchronized with one or more EMGs from selected muscles with little electrical noise or movement artifact interference. The system employs telemetry which is compared to hardwire techniques.