Uncontrollable shock proactively increases sensitivity to response-reinforcer independence in rats

Learned helplessness theory predicts that animals exposed to inescapable shock acquire an expectancy of response-reinforcer independence, which proactively interferes with learning of response-reinforcer dependence. The theory also predicts that this expectancy can increase sensitivity to subsequent instances of response-reinforcer independence. These experiments test the latter prediction in a paradigm that minimizes the confounding effects of shock-induced activity deficits. Rats were trained to respond for food, then given either escapable, inescapable, or no shock. Subsequently, they received two sessions of response-contingent food followed by sessions of noncontingent food deliveries. During this phase, inescapably shocked animals decreased responding faster than did controls. Experiment 2 replicated this finding with a different schedule of food delivery and a procedure that more directly minimized the possibility that the outcome is due to either direct or indirect shock-induced activity changes. These results support the prediction that uncontrollable aversive events can increase an animal's sensitivity to noncontingent response-reinforcer relationships.     

Schedule-induced behavior in hyperactive children

A schedule-induced behavior paradigm was used to investigate the activity patterns of hyperactive children in a standardized situation. In Experiment I, 10 hyperactive and 10 normal control children matched for age, sex, and IQ were observed under conditions of baseline and schedule. Measures of a number of categorized activities were taken on a time-sampling basis. Hyperactive children were more active than controls in baseline and did not respond to the schedule, unlike the controls who became significantly more active in schedule conditions. In Experiment II, 12 hyperactive and 6 normal children were again subjected to the same experimental paradigm, but in two of the four experimental sessions the stimulant drug methylphenidate was administered in an attempt to reduce the amount of baseline activity. Results were substantially similar to those of Experiment I, with hyperactive children more active than controls in baseline and insensitive to the schedule. There was no overall effect of drug administration on the behavior of either group. There were some ratedependent effects of both drug and schedule conditions.     

Acquisition and retention of gestures by apraxic patients

The purpose of this study was to examine whether apraxic-aphasic patients with parietal lesions had difficulty learning lists of gestures and whether the performance deficits they displayed resulted from an inability either to consolidate this information in memory or to retrieve the information once stored. The findings indicate that apraxic-aphasic patients do have difficulty acquiring lists of gestures. This inability to reproduce gestural information was not associated with a retrieval disorder, but instead the apraxic-aphasic subjects could not consolidate the information in memory.     

Explaining the Psychological Effects of Unemployment for Young People: The Importance of Specific Situational Factors

Evidence of the effects of duration of unemployment and gender upon the psychological response to unemployment is reviewed. It is suggested that many of the apparent contradictions in this evidence can be resolved by reference to situational factors which shape how stressful unemployment is for a particular individual. The study reported tested the effects of a stressful period of unemployment on the psychological well-being, self-esteem and life-satisfaction of young people. No sex differences in response to unemployment were found, and this is explained in terms of the similarity of their experiences. The relevance of these findings for counselling the unemployed is discussed.