The effect of cuing after backward conditioning trials

Rats were given backward pairings of a tone (CS) and shock (US) and were then tested for response to the CS in a lick suppression test. Animals given a cuing or reminder treatment prior to the test exhibited enhanced suppression in the presence of the tone relative to a variety of control conditions. The cue-induced suppression enhancement did not appear to result from sensitization or short-term motivational changes nor did it seem to depend on second-order conditioning of the test context. The effect appeared more robust as the number of backward conditioning trials preceding the cue increased. The results were discussed in terms of current explanations of backward conditioning effects.     

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.     

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of the experience itself.Excerpted from The Effect of Divorce on Spiritual Growth: A Study in Protestant Spirituality (unpublished thesis), (c) 1984 Jean M. Blomquist.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.     

Representation and retention of three-event sequences in pigeons

The present experiments studied a three-event delayed sequence-discrimination (DSD) task: one arrangement (order) of two stimuli (red and yellow overhead lights) taken three in succession (e.g., red, yellow, red) was the positive sequence and the remaining seven arrangements were the negative sequences for responding and reward during the subsequent test stimulus. In Experiment 1, the final stimulus (recency) and the order of stimuli in the positive sequence controlled acquisition of discrimination. In Experiment 2, increasing the duration of memory intervals between stimuli reduced the discriminability of those negative sequences identical to the positive sequence after the delay. Three-event DSD performance in Experiments 1 and 2 was similar to two-event DSD performance in comparable published experiments. Models developed to explain pigeon performance in two-event DSD were extended to the three-event task. Results from both two- and three-event versions of the DSD task falsified a noncumulative model and several cumulative integration models (i.e., adding, averging, and some multiplying models), but corroborated one cumulative, multiplying model.     

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.     

Interpersonal attraction,social identification and psychological group formation

Two perspectives on the nature of the social group and psychological group formation are discussed. The traditional social cohesion approach traces group formation to processes of interpersonal attraction, while the social identity approach defines the group in cognitive terms and considers identification, or self-categorization, to be the mechanism of psychological group formation. On the basis of an experiment by Turner, Sachdev and Hogg (1983) it is hypothesized that interpersonal attraction (positive or negative) is related to group formation only in so far as it enhances intergroup distinctiveness. This hypothesis is experimentally tested in a 2 × 3 (interpersonal liking/disliking per se versus no explicit categorization/random categorization/criterial categorization on the basis of affect) factorial design employing the ‘minimal group’ paradigm. People who like each other and were not explicitly categorized formed a group. This effect was enhanced by criterial categorization but disappeared when categorization was random. Although the results do not support the hypothesis, they are not explicable in social cohesion terms. A social identity explanation is furnished—attraction influences group formation by acting, under certain specifiable conditions, as a cognitive criterion for common category membership. This explanation is located in current theorizing and is proposed as part of a reconceptualization of the relationship between interpersonal attraction and group formation.     

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.     

Clauses and the semantic representation of words

When a sentence with more than one clause is processed, words of the first clause become less available for recall or recognition once the clause boundary has been passed. One common interpretation of this observation is that the representation of a given word shifts from a predominantly surface form (e.g., phonological or lexical) to a semantic form, after the clause boundary. Two experiments that test that interpretation are reported. In the first experiment, two-clause spoken sentences were followed by spoken word or picture probes. Pictures were intended to provide a fast semantic match to probed words, but a slow surface match. Although response times exhibited a robust main effect of the clause position of the probe, no interaction with probe type was found. Similar results were obtained in a second experiment that compared pictures with written word probes. The faster response to picture than to word probes in the second experiment indicates that subjects did not covertly name the picture, but made a semantic match (as intended). These observations suggest the following reinterpretation of earlier sentence memory experiments: Words in the most recent clause of a sentence are more available than words in an earlier clause because their semantic representations are more active, not because their surface representations are more active.