Plasticity associated with escalated operant ethanol self-administration during acute withdrawal in ethanol-dependent rats requires intact matrix metalloproteinase systems

Repeated cycles of ethanol intoxication and withdrawal associated with dependence induce neuroadaptations in a variety of brain systems. Withdrawal-induced negative emotional states can be ameliorated by ethanol consumption; a learned process termed negative reinforcement. Accordingly, a dependence-induced phenotype is escalated ethanol self-administration. Matrix metalloproteinases (MMPs) are proteolytic enzymes which degrade the extracellular matrix to allow for synaptic reorganization and plasticity. To test the hypothesis that an intact MMP system is required for animals to learn about the negative reinforcing effects of ethanol and display escalated self-administration during acute withdrawal when ethanol-dependent, male Wistar rats were trained to self-administer ethanol and then assigned to either acute or chronic MMP inhibition treatment groups. The chronic treatment group received intracerebroventricular (ICV) infusions of the broad spectrum MMP inhibitor FN-439 or artificial cerebrospinal fluid (aCSF) via osmotic minipumps during a 1 month ethanol dependence induction period and subsequent post-dependence induction self-administration sessions that occurred during acute withdrawal. The acute treatment group only received ICV FN-439 or aCSF on the day of self-administration sessions following dependence induction during acute withdrawal. The results showed that inhibition of MMPs attenuated escalated ethanol self-administration following chronic and acute exposure conditions. Furthermore, once learning (i.e., plasticity) had occurred, MMP inhibition had no impact on escalated response patterns and animals previously subjected to MMP inhibition that did not escalate evidenced normal escalations in operant ethanol self-administration once FN-439 treatments were terminated. Thus, the present data identified that an intact MMP system is required for the escalated responding that occurs during acute withdrawal in dependent animals and implicate such escalation as a learned response.     

The role of attractiveness and aggression in high school popularity

This study examines the effects of physical attractiveness and aggression on popularity among high school students. Previous work has found positive relationships between aggression and popularity and physical attractiveness and popularity. The current study goes beyond this work by examining the interactive effects of physical attractiveness and aggression on popularity. Controlling for race and gender, the results indicate that attractive students are seen as more physically and relationally aggressive than those who are less attractive. We also found that those who are both physically attractive and aggressive are perceived to be more popular than those without such characteristics. However, the same interaction showed the opposite effect when predicting sociometric popularity instead of perceived popularity. These results contribute to the understanding of the differences between those who are well-liked (sociometric popularity) and those who are socially visible (perceived popularity), and the unique predictors of these two dimensions of status in the peer group.     

A preliminary examination of the effect of massage on state body image

Evidence suggests positive effects of massage on psychological health; however, little is known about the effects of massage on body image. This research examined the effect of massage on state body image as well as relations between trait body image and attitudes toward massage. Forty-nine female university students were randomly assigned to either a massage condition or a control condition. It was hypothesized that participants in the massage condition would report improved state body image following the intervention when compared to participants in the control condition. As predicted, participants in the massage condition reported a more favorable state body image than participants in the control condition post-manipulation. Certain body image evaluations were moderately associated with views that massage is pleasurable, with the link between Body Areas Satisfaction and viewing massage as pleasurable reaching significance. Research is needed to determine the mechanism/s through which massage improves body image.     

The mini-IPIP scales: tiny-yet-effective measures of the Big Five factors of personality

The Mini-IPIP, a 20-item short form of the 50-item International Personality Item Pool-Five-Factor Model measure (Goldberg, 1999), was developed and validated across five studies. The Mini-IPIP scales, with four items per Big Five trait, had consistent and acceptable internal consistencies across five studies (= at or well above .60), similar coverage of facets as other broad Big Five measures (Study 2), and test-retest correlations that were quite similar to the parent measure across intervals of a few weeks (Study 4) and several months (Study 5). Moreover, the Mini-IPIP scales showed a comparable pattern of convergent, discriminant, and criterion-related validity (Studies 2-5) with other Big Five measures. Collectively, these results indicate that the Mini-IPIP is a psychometrically acceptable and practically useful short measure of the Big Five factors of personality.     

Facilitation of receptive and productive foreign vocabulary learning using the keyword method: the role of image quality

Ellis and Beaton (1993a) reported that the keyword method of learning enhanced memory of foreign vocabulary items when receptive learning was measured. However, for productive learning, rote repetition was superior to the keyword method. The first two experiments reported here show that, in comparison with rote repetition, both receptive and productive learning can be enhanced by the keyword method, provided that the quality of the keyword images is adequate. In a third experiment using a subset of words from Ellis and Beaton (1993a), the finding they reported, that for productive learning rote repetition was superior to the keyword method, was reversed. The quality of keyword images will vary from study to study and any generalisation regarding the efficacy of the keyword method must take this into account.     

The gender similarities hypothesis

The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses support the gender similarities hypothesis. Gender differences can vary substantially in magnitude at different ages and depend on the context in which measurement occurs. Overinflated claims of gender differences carry substantial costs in areas such as the workplace and relationships.     

Changing Trends in Doctoral Training Programs in Psychology: A Comparative Analysis of Research-Oriented Versus Professional-Applied Programs

Data from the National Research Council's 1995 study of doctoral programs provide a basis for the comparison of research-oriented Ph.D. programs in psychology and Ph.D. programs of professional-applied schools. The latter present a profile of faculty resources, attributes, and activities that differs sharply from that found in the research-oriented programs, and in Ph.D. programs in the other behavioral and social sciences. The difference in profiles suggests that the professional programs conduct Ph.D. training that departs from the training ordinarily regarded as necessary for the award of that degree.     

The effects of ambient temperature and insult on the motivation to retaliate or escape

In order to investigate the impact of high ambient temperature on the motivation of angered persons, 48 men were either insulted or not insulted under normal or excessively hot conditions. The men received ratings from a partner that conveyed a negative or neutral personality evaluation, ostensibly as part of an impression-formation task. During this time, the participants were exposed to normal or excessively hot temperatures in an experimental room while their partners were in a normal temperature room. The subjects were subsequently given the opportunity to choose between two tasks for the next part of the study. One task, described as tedious, permitted their leaving the situation earlier than did the other task, described as involving administration of white noise to their partner. The results revealed that the insulted relative to noninsulted men more often chose to participate in a potentially aggressive interaction in the normal conditions whereas insulted relative to noninsulted men chose more often to participate in a nonaggressive task in the hot conditions. The design of the study precluded a shared stress interpretation of the data. Supplementary data were interpreted as supporting a negative affect rather than an attributional interpretation of the results.