The impact of emotional stress early in life on adult voluntary ethanol intake-results of maternal separation in rats

The combination of genetic and environmental factors determines the individual vulnerability for excessive ethanol intake, possibly leading to dependence. The environmental influences early in life represent examples of determinant factors for adult behaviour and can be protective as well as risk factors. Maternal separation is one model to examine the long-term consequences of early environmental experiences on neurochemistry and behaviour, including drug-taking behaviour in experimental animals. In the present review, findings from studies using repeated short and prolonged periods of maternal separation, with emphasis on effects on voluntary ethanol intake in rats with or without a genetic predisposition for high voluntary ethanol intake, are summarized. Despite some contradictory results, the general picture emerging shows that short periods of maternal separation during the postnatal period result in a lower adult voluntary ethanol intake in male rats. Prolonged periods of maternal separation were found to induce a high voluntary ethanol intake in male rats, including rats with a genetic predisposition for high ethanol intake. Results from the literature also show that changes were not just related to time of separation but were also related to the degree of handling. Interestingly, in terms of voluntary ethanol intake, female rats were generally not affected by postnatal maternal separation. The reasons for these sex differences need further investigation. In terms of neurobiological consequences of maternal separation, conclusive data are sparse and one of the future challenges will, therefore, be to identify and characterize underlying neurobiological mechanisms, especially in the individual animal.     

Social attitudes and education: Self-selection or socialization?

The aim of this study was to replicate earlier findings (Ekehammar et al., 1987) concerning the relationship between social attitudes and educational direction and field of study, by addressing further the causality issue. The sample comprised 256 Swedish adolescents from metropolitan Stockholm attending the two lowest grades in secondary school (modal age was 17 years). The main findings of the previous study were replicated, although the statistical power was weaker. Two higher-order attitude dimensions (labeled Political-economic conservatism and Social conservatism) discriminated between six groups, based on combinations of the two aspects of education. The main picture evidenced a socialization effect regarding Political-economic conservatism and a self-selection explanation for Social conservatism. Introducing intellectual ability as an independent variable in the causal model, affecting both educational direction and social attitudes, weakened the relationship, as compared to the previous study.     

Determinants of cumulative successive contrast in saltiness intensity judgments

When all stimuli elicit the same taste quality, solutions preceded by a high concentration level are judged to be significantly less intense than solutions preceded by a low concentration level. After repetitious stimulation with a different tasting stimulus, the intensity of the present stimulus is overestimated. This phenomenon is called “successive contrast.” In the present study, the cumulative effects of three identical stimuli on the saltiness ratings for a test stimulus are investigated. The preceding stimuli are manipulated with regard to taste quality, saltiness intensity, total taste intensity, and complexity. Whether the size of the cumulative contrast effect is associated with the degree of dissimilarity between preceding stimuli and test stimulus, or with the saltiness or total taste intensity of the preceding stimuli, is investigated. The size of the contrast effect depends on the type of preceding stimulus, its intensity, and the type of test stimulus. No association was found with judgments of the degree of dissimilarity between the preceding stimuli and the test stimulus. For nonsalty preceding stimuli, the contrast effects are independent of concentration level. When the preceding stimuli taste at least partly salty, the total intensity appears to determine the size of the contrast for an unmixed salty test stimulus.     

Women as cues for men's approach or distancing behavior: A study of interpersonal sexist discrimination

The purpose of this study was to investigate interpersonal sexist discrimination, operationally defined as distancing behavior. A heterogeneous sample of participants were approached at four train stations and completed two paper and pencil simulated seating measures, a sex role attitudes measure, and provided demographic information. It was predicted that in the neutral situations presented in the seating measures where there is a choice to sit either next to a man or a woman, men would more often choose to sit next to a man but women were not expected to make seating choices based on the gender of the person seated. Men's seating choices were found to be influenced by the gender of target persons whereas women's choices were not, but men either distanced from or approached women target persons. Self-reported sex role attitudes were found not to be related to distancing behavior.We gratefully acknowledge the assistance of Alyson Andrews, Nicholas Geraci, Scott Marino, Stacy Schiff, Robert Victoria, and Lisa Zamara, seniors at the University of Rhode Island, who served as investigators in this study and also assisted in the coding of data. Portions of this paper were presented at the national conference of the Association for Women in Psychology in Oakland, CA, on March 6, 1994.Requests for reprints may be sent to any of the authors at the University of Rhode Island, Department of Psychology, Kingston, RI 02881.     

CHANGE IN AFTERIMAGE AND SPIRAL AFTEREFFECT SERIALS DUE TO ANXIETY CAUSED BY SUBLIMINAL THREAT

Experiments with projected negative afterimages and with the aftereffects of a rotating spiral were performed serially (repeated stimulus presentation). In the middle of the sequences the experimental groups were subjected to subliminal threat by means of a metacontrast technique. The effects of threat on the latter part of the sequences were according to predictions and differed markedly from the results in control groups.     

On the role of causal intervention in multiple-cue judgment: positive and negative effects on learning

Previous studies have suggested better learning when people actively intervene rather than when they passively observe the stimuli in a judgment task. In 4 experiments, the authors investigated the hypothesis that this improvement is associated with a shift from exemplar memory to cue abstraction. In a multiple-cue judgment task with continuous cues, the data replicated the improvement with intervention and participants who experimented more actively produced more accurate judgments. In a multiple-cue judgment task with binary cues, intervention produced poorer accuracy and participants who experimented more actively produced poorer judgments. These results provide no support for a representational shift but suggest that the improvement with active intervention may be limited to certain tasks and environments.