Temporal proximity and reinforcement sensitivity in multiple schedules

Distributions of reinforcers between two components of multiple variable-interval schedules were varied over a number of conditions. Sensitivity to reinforcement, measured by the exponent of the power function relating ratios of responses in the two components to ratios of reinforcers obtained in the components, did not differ between conditions with 15-s or 60-s component durations. The failure to demonstrate the “short-component effect,” where sensitivity is high for short components, was consistent with reanalysis of previous data. With 60-s components, sensitivity to reinforcement decreased systematically with time since component alternation, and was higher in the first 15-s subinterval of the 60-s component than for the component whose total duration was 15 s. Varying component duration and sampling behavior at different times since component transition may not be equivalent ways of examining the effects of average temporal distance between components.     

Sequential effects in dimensional contrast

Two experiments examined pigeons' response rates during short trials signaled by stimuli closely spaced along a wavelength continuum. In Experiment 1 separate halves of the continuum were correlated with different reinforcement schedules. In Experiment 2, the middle stimulus was accompanied by a lower probability of reinforcement than were the remaining wavelengths. Both procedures resulted in dimensional contrast “shoulders,” seen as relatively enhanced or depressed response rates in the presence of stimuli between the extreme of the continuum and the border separating the positive and negative stimuli. Sequential analyses addressed possible contributions of the following interactions: (a) local contrast, seen when rate during a given schedule depends on the schedule in the just-preceding trial; (b) modification of local contrast by the similarity of the signaling stimuli (P. Blough, 1983); and (c) schedule-independent rate contrast, seen when rate in a given trial depends on the rate controlled by the stimulus that accompanied the just-preceding trial (Malone & Rowe, 1981). Dimensional contrast functions were similar when isolated according to the schedule, to the similarity of the signaling stimulus, and to the response rate of the just-preceding trial. The interactions noted above do not appear to make important contributions to this effect.     

On narcissism and post-narcissism: Psychology and theology in context

A contextual approach to narcissism is developed in which theology is seen to articulate simultaneously with psychological needs and cultural values. Some implications of the psychology of the self for theology and culture are discussed in this framework.The author wishes to express his gratitude to Dr. Larry K. Graham for his comments on an earlier version of this paper.Dr. Fallot is a psychologist on the staff of the Student Counseling Service, University of Illinois at Chicago, P.O. Box 4348, Chicago, Il. 60680.     

The effect of the divorce experience on spiritual growth

This essay presents the findings from a study of the effect of divorce on spiritual growth among Protestants. Looking at movement in the areas of love of God, self, and others, it shows that the divorce experience can have varying levels of impact which relate at least partially to the traumatic intensity of the experience itself.Excerpted from The Effect of Divorce on Spiritual Growth: A Study in Protestant Spirituality (unpublished thesis), (c) 1984 Jean M. Blomquist. All rights reserved.     

Visual dominance in inhibitory conditioning in the pigeon

In a conditioned inhibition paradigm (A+, B+, AX?_, pigeons received either of two keylight stimuli reliably followed by food (A+, B+). However, when one of these keylights was accompanied by another stimulus, food did not follow (AX?). For some groups, the putative inhibitor was a tone, whereas for others it was illumination of a red houselight. The birds pecked the A and B stimuli at a high rate. When X was red houselight, the birds pecked A at a much lower rate in the presence of X. When X was a tone, discrimination between A and AX was much poorer. Moreover, in a transfer test, red houselight inhibited responding to the other keylight, B, but tone did not. These results indicate that red houselight becomes a conditioned inhibitor more quickly than tone in appetitive situations, just as red houselight becomes a conditioned excitor more quickly in those situations. These results contradict the assertion that the latter outcome occurs because red houselight is a stronger appetitive excitor than tone at the start of the experiment (the “head start” hypothesis).     

Induction of depressive affect after prolonged exposure to a mildly depressed individual

Scores on the Beck Depression Inventory (BDI) were periodically obtained from the roommates of college students who exhibited a persistent mild depression over a 3-month period. For comparative purposes, BDI scores were also obtained from roommates of individuals who were transiently depressed and from subjects with nondepressed roommates. In comparison with control subjects, the roommates of persistently depressed persons displayed a progressive increase in BDI score over the course of the study.     

Infant hypotonia, obesity, hypogenitalism and oligophrenia--new viewpoints on the etiology and symptoms of Prader-Willi syndrome

We present four cases of Prader-Willi syndrome. Two of them have an abnormality of a chromosome 15, the other both show different chromosomal abnormalities. Translocations or deletions were found recently in the bands 15q11/12 in about 60% of the cases of Prader-Willi syndrome. The consequences for diagnosis, symptomatology and genetic counselling of the syndrome are discussed.     

Preference for decision structures in a social dilemma situation

Additional results from Rutte and Wilke's (1984) study are presented. In the context of a social dilemma situation two variables were manipulated: use and variance. Preference for various decision structures is the issue of the present paper. It appeared that a large majority structure and an unanimity structure were mast preferred. A small majority structure and a structure in which each decides for him/herself were intermediately preferred. Whereas a structure in which one person, a leader, decides for all was least preferred. Further analysis of these data suggested that only the latter two decision structures were influenced by the use and variance manipulations.