Drug effects on responding maintained by stimulus-reinforcer and response-reinforcer contingencies.

The effects of pentobarbital and d-amphetamine were assessed on key pecking by pigeons under conventional single-key multiple schedules and under two-key multiple schedules in which discriminative stimuli appeared on one key (stimulus key) while pecks on a second key (constant key) produced food. Pecks on the stimulus key had no scheduled consequences. A 60-second variable-interval schedule operated in one component of each multiple schedule: either extinction or a 60-second variable-time schedule operated in the alternate component. When the alternate-component schedule was extinction, a high rate of responding was maintained in the variable-interval component of the single-key schedule; responding on both keys was maintained in the variable-interval component of the two-key schedule. Pentobarbital increased responding in the variable-interval component of the single-key schedule and increased stimulus-key, but not constant-key responding in that component of the two-key schedule. When the alternate-component schedule was changed to variable time, responding declined in the variable-interval component of the single-key schedule; stimulus-key responding was no longer maintained under the two-key schedule. Pentobarbital decreased responding in the variable-interval component of both schedules. With an exception, d-amphetamine only decreased responding in the variable-interval component of the single- and two-key schedules both when the alternate-component schedule was extinction and when it was variable time. The results suggest that the effects of pentobarbital, but not d-amphetamine, depend on the nature of the contingency (stimulus-reinforcer, response-reinforcer) that maintains responding.     

In search of depth

Four experiments designed to investigate a visual search task are reported. In each experiment, subjects searched for either a two-dimensional shape rotated in depth among frontal-parallel distractors or a frontal-parallel shape among distractors that were rotated in depth. The principal independent variable was search-set size. In addition, over the four experiments, a variety of spatial arrangements and two axes of rotation in depth were sampled. The chief aim of the experiments was to adduce evidence bearing on the attentional demands of searching for depth. The slopes of the reaction-time (RT) functions were taken as diagnostic. Experiments 1–3 exhibited positive slopes for the RT-set-size function. These slopes appear to be due to a conscious adoption of a serial search strategy by the subjects. When this tendency was suppressed by the procedures of Experiment 4, the slope of the RT-set-size functions did not differ significantly from zero. We conclude that, in agreement with the findings of other studies, slant-in-depth can be detected preattentively.     

Plekhanov on the role of the individual in history

This essay critically assesses Plekhanov's famous article on the role of the individual in history. Part I explicates his treatment of the problem of free will and determinism and argues that it is unsatisfactory. The whole issue, however, is held to be largely irrelevant to Marxism. Part II then turns to the question of the explanatory weight given to individual action by historical materialism. Plekhanov's discussion of this issue is more insightful, and the essay endeavors to distinguish between the strong and weak points of his analysis in order to lay the foundations for a more adequate handling of the subject.     

A look at social support patterns

The issue of how to provide support for patients with a life-threatening illness continues to be a problem for pastors and chaplains. The authors discuss the significance and reasons for looking at the present day social support patterns as an unnatural problem. Unless the unnatural nature of support in the modern medical setting is understood pastors and chaplains can miss the target on answering the question of how to provide support. The authors conclude the article by addressing this question from the position of reserving the unnatural nature of providing support.Dr. Bergen is Professor of Psychiatry, Dartmouth Medical School, Hanover, NH 03755. Dr. Nelson is affiliated with the Chaplain Service, Veterans Administration Center, White River Junction, VT 05001 and Assistant Professor of Clinical Psychiatry, Dartmouth Medical School.     

PROCEDURAL VARIATIONS IN GROUP CONTINGENCIES: EFFECTS ON CHILDREN'S ACADEMIC AND SOCIAL BEHAVIORS

There has been little research on the effects of the many procedural variables in applied group contingencies. In the present study, an individualized contingency and three group contingencies with different “responder” criteria (e.g., reward based on the group average, reward based on the work of a designated, low-achieving student, or reward based on the work of a randomly selected student) were applied to the academic work of primary grade children in a learning disabilities classroom. Group social interaction during each contingency was measured systematically. Although there were large individual differences in students' academic and social responses to the different contingencies, some consistent effects were observed. Two of the four low-achieving target students did their best academic work during the group contingency which focused on their performance as a designated responder. This type of contingency also produced high levels of positive social interaction in three of four groups of children observed.     

A microcomputer-based system for evoked-potential augmenting/reducing measurements

Evoked-potential measurements can readily be implemented on a microcomputer. We present as an example a system for obtaining an evoked-potential augmenting/reducing measure using the Apple II microcomputer. Specialized features of the PASCAL program and peripheral equipment are described.     

Creative Pseudo-Reality as a Defensive Factor in Jewish Wit: A Dialectical Perspective

Theoretical dynamics of ethnic humor are juxtaposed with Jewish wit, showing that there is a distinct factor which operates in the Jewish humor response to oppression. Drawing from Ziv's (1986) rich anthology of research and case studies, this factor is conceptualized as creative pseudo-reality. It is hypothesized that Jewish wit features this element of self-effacing humor besides the factors which it shares with the ethnic humor of other marginal groups. The implicit ability to construct a perceived environment which is bound neither to reason nor to logic, is seen as the last line of defense for an oppressed minority whose other options have been denied. Irony and triumph, suggested as key elements in this factor, are illustrated in annotated stereotypical excerpts of Jewish wit. Throughout the analysis, the dialectic principle—maintaining the co-existence of inconsistent dynamics—is highlighted in contrast to the reductionistic either/or approach commonplace in psychological and sociological discourse.     

The Validity of the Rorschach and the Minnesota Multiphasic Personality Inventory: Results from Meta-Analyses

Results from meta-analyses have been widely cited to defend the validity of the Rorschach. However, the meta-analyses have been flawed. For example, one meta-analysis included results that were obtained by calculating correlations but not results that were obtained by conducting t tests or analyses of variance. When we reanalyzed the data from the most widely cited meta-analysis (Parker, Hanson, & Hunsley, 1988), we found that for confirmatory studies (also called convergent-validity studies), the Minnesota Multiphasic Personality Inventory (MMPI) explained 23% to 30% of the variance, whereas the Rorschach explained only 8% to 13% of the variance. These results indicate that the Rorschach is not as valid as the MMPI.     

Optimism and Pessimism in Business Leaders1

Male business leaders responded to 3 instruments, the Leadership Practices Inventory (LPI-SELF), the Kirton Adaption-Innovation Inventory (KAI), and a measure of optimism and pessimism (O/P). Approximately 5 to 6 (range = 3 to 9) of each of the 48 leaders' direct reports rated their leaders on the LPI (LPI-OBSERVER) and also responded to the O/P instrument. As predicted, both the leaders and their direct reports had lower mean scores on pessimism than a normative group; neither group differed from the norm on optimism. The leader KAI scores were negatively correlated with pessimism, and positively, though not significantly so, with optimism. Optimism was positively correlated with 2 factors of the LPI-OBSERVER, but pessimism was not correlated with any of the five LPI factors.