Delayed temporal discrimination in pigeons: A comparison of two procedures

A within-subjects comparison was made of pigeons' performance on two temporal discrimination procedures that were signaled by differently colored keylight samples. During stimulus trials, a peck on the key displaying a slanted line was reinforced following short keylight samples, and a peck on the key displaying a horizontal line was reinforced following long keylight samples, regardless of the location of the stimuli on those two choice keys. During position trials, a peck on the left key was reinforced following short keylight samples and a peck on the right key was reinforced following long keylight samples, regardless of which line stimulus appeared on the correct key. Thus, on stimulus trials, the correct choice key could not be discriminated prior to the presentation of the test stimuli, whereas on position trials, the correct choice key could be discriminated during the presentation of the sample stimulus. During Phase 1, with a 0-s delay between sample and choice stimuli, discrimination learning was faster on position trials than on stimulus trials for all 4 birds. During Phase 2, 0-, 0.5-, and 1.0-s delays produced differential loss of stimulus control under the two tasks for 2 birds. Response patterns during the delay intervals provided some evidence for differential mediation of the two delayed discriminations. These between-task differences suggest that the same processes may not mediate performance in each.     

Leadership skills and helpful factors in self-help groups

The effects of training on leadership skills and group processes in cancer and anorexic self-help groups are investigated. Three components of the study are reported. Firstly, an observational case-study of each type, of group was conducted to investigate the nature of the leadership input. Secondly, a Self-Help Questionnaire based on Lieberman's classification of leadership skills was administered to members of eight self-help groups to compare the experiences of groups with trained and untrained leaders. Thirdly, group members completed a Helpful Factors Questionnaire based on Yalom's analysis of group processes. The observational case-study revealed significant differences between the trained and untrained leaders in that, unlike the trained leader, the untrained leader clearly dominated the group. Results from the Self-Help Questionnaire showed that trained leaders scored higher on Caring and Emotional Stimulation but lower on Attribution of Meaning. Member satisfaction, however, was similar in the two types of group. Results from the Helpful Factors Questionnaire showed that most of the helpful factors were seen similarly by the two types of group, though differences were found concerning the relative rankings of both Guidance and Altruism. It is concluded that some degree of training of group leaders could be usefully incorporated into the self-help movement.