Reinforcement and the organisation of behaviour in golden hamsters: Differential overshadowing of a CS by different responses

Are different responses differentially associable with their consequences? An overshadowing design was used to try to answer this question for three responses previously studied in golden hamsters. In Experiment I, scrabbling was rapidly suppressed by electric shock punishment, and it overshadowed a tone which occurred between scrabbling and shock. In Experiment II, no evidence of response-shock association was obtained when open rearing was the punished response, and open rearing did not overshadow the tone. Punishment had some effect on face washing, but there was no statistically significant overshadowing with this response. These results are consistent with the idea that differences in punishment suppression among these three responses have an associative basis. They also demonstrate the usefulness of a novel paradigm for studying “preparedness” of response-reinforcer associations.     

Parallel distributed processing and neuropsychology: A neural network model of Wisconsin card sorting and verbal fluency

Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.     

HIV infection--psychological coping and political reality

The authors warn against a trivialization of the AIDS problem and against the call for state control. Since sexuality is ultimately uncontrollable, they plead instead for the greater clarification of the conflicts which those who are infected with HIV and those who are not infected experience in dealing with each other. The continuing mystification of these conflicts would result in mutual jeopardy through acting-out.     

Challenging occupational stereotypes: Women's training roadshows and guidance at school level

The views that women and girls hold about themselves contribute to the segregation of women in the labour market. Women's Training Roadshows are an example of initiatives aimed at 'cultural interruption', in that they attempt to challenge occupational stereotypes. This paper evaluates the Cardiff Women's Roadshow from the schoolgirls' perspective and discusses the implications of the findings for careers guidance at school level.     

Computer Communication and Organizational Commitment: Tracing the Relationship in a City Government

Various theories and management policies suggest that there should be a positive relationship between communication and commitment to the organization. However, support for that relationship remains equivocal. We report the results of a questionnaire on communication and commitment filled out by 376 employees of a mid-sized city government. They were asked about the mode and frequency of their communications within the organization and about their commitment to the city government. Consistent with our hypotheses about the nature of computer-mediated communication, use of computer mail and bulletin boards predicted organizational commitment, but use of the telephone and paper modes of communication did not. In addition, those most likely to benefit from the immediacy and memory of computer communication—shift workers—evidenced a stronger relationship between computer mail use and commitment than did regular employees. Two mechanisms for mediating the relationship between communication and commitment were evaluated. Evidence supports active participation in communication as a mediating mechanism in the relationship between communication and commitment. The informational value of communication does not appear to be important in this regard.     

Attributional mediators of social inhibition and avoidance

People differ in the degree to which they become inhibited and avoidant when they feel socially anxious This study explored the hypothesis that characterological attributions for one's feelings of nervousness in social settings are related to social inhibition and avoidance In a preliminary study, the dimensions people use to explain their feelings of nervousness and relaxation were determined One hundred and twenty-five subjects then completed measures of social anxiousness, inhibition, and avoidance, and made attributions for feeling nervous and relaxed in 10 interpersonal scenarios As predicted, attributions of nervousness to characterological factors, such as ability and personality traits, correlated positively with social inhibition and avoidance Unexpectedly, behavioral attributions for nervousness also predicted inhibition and avoidance     

Effects of neonatal forebrain noradrenaline depletion on recovery from brain damage: performance on a spatial navigation task as a function of age of surgery and postsurgical housing

The experiments examined the contributions of forebrain noradrenaline and environmental enrichment to recovery of place navigation ability in rats after hemidecortication in infancy or adulthood. Noradrenaline depletion did not affect recovery from neonatal hemidecortication, although the early hemidecortications did allow sparing of function relative to adult operates. Noradrenaline depletion also failed to attenuate the positive effects of enriched housing on otherwise normal rats. Noradrenaline depletion did retard recovery of adult hemidecorticate rats housed in standard laboratory cages, but it did not retard recovery of adult hemidecorticate rats housed in enriched environments. The results suggest that noradrenaline is importantly involved in enhancing recovery from brain damage when other sources of compensation (e.g., neonatal injury, enriched environment) are absent.     

Sex differences in the effects of gonadectomy on amphetamine-induced rotational behavior in rats

The effects of gonadectomy on amphetamine-induced rotational behavior were studied in male and female rats. Different systemic doses were used to produce equivalent brain concentrations of the drug in each group, thereby controlling for sex differences in the metabolism of amphetamine. Ovariectomy of female rats significantly attenuated amphetamine-induced rotation, whereas castration of males was without effect. The results support the idea that in females, the endogenous gonadal hormones facilitate functional activity in the mesostriatal dopamine system.