Effects of Posttraining Intrahippocampal Injections of Platelet-Activating Factor and PAF Antagonists on Memory

The present experiments examined the effects of posttraining intrahippocampal injections of the degradative enzyme-resistant methylcarbamyl analog of the bioactive phospholipid platelet-activating factor (mc-PAF) and the platelet-activating factor (PAF) receptor antagonists BN52021 and BN 50730 on memory in male Long-Evans rats trained in a hidden platform version of the Morris water maze. Following an eight-trial training session, rats received a unilateral intrahippocampal injection of mc-PAF (0.5, 1.0, or 2.0 μg/0.5 μl), lyso-PAF (1.0 μg/0.5 μl), the cell surface PAF receptor antagonist BN 52021 (0.25, 0.5, or 1.0 μg/0.5 μl), the intracellular PAF receptor antagonist BN 50730 (2.0, 5.0, or 10.0 μg/0.5 μl), or vehicle (50% DMSO in 0.9% saline; 0.5 μl). On a retention test conducted 24 h after training, the escape latencies of rats administered mc-PAF (1.0 or 2.0 μg) were significantly lower than those of the vehicle-injected controls, demonstrating a memory-enhancing effect of mc-PAF. Injections of lyso-PAF, a structurally similar metabolite of PAF, had no influence on memory, indicating that the memory-enhancing effect of mc-PAF is not caused by membrane perturbation by the phospholipid. The retention test escape latencies of rats administered BN 52021 (0.5 μg) and BN 50730 (5.0 or 10 μg) were significantly higher than those of the controls, indicating a memory impairing effect of both PAF antagonists. When mc-PAF, BN 52021, or BN 50730 was administered 2 h posttraining, no effect on retention was observed, indicating a time-dependent effect of the neuroactive substances on memory storage. The findings suggest a role for endogenous PAF in hippocampal-dependent memory processes.     

Multiple-feature discrimination faster than single feature discrimination within the same object?

In the present study, we investigated whether judging the presence of multiple features within an object would be superior to judging the presence of only one feature. Feature discriminability and the number of features to discriminate within an object were varied. Specific features were judged as present or absent. Results showed that judging the presence of two or three features was faster than judging the presence of the less discriminable of these two or three features alone (multiple-feature benefits). These findings suggest that relevant features within an object activate (prime) a decision or response in a parallel, asynchronous fashion based on discriminability (Miller, 1982a). The ability of a response priming model, a response mapping model, and a template model to account for multiple feature benefits is discussed.     

The trajectory of a dot crossing a pattern of tilted lines is misperceived

The straight trajectory of a dot crossing a pattern of tilted lines is perceived as being sinusoidal. Manipulation of the size of the angle between the trajectory and the tilted lines, the velocity of the dot, and the distance between the tilted lines shows that the magnitude of the illusion is inversely proportional to the size of the incidence angle, to velocity, and to the distance between the lines. The illusion is interpreted as being the result of an integration process of local distortions occurring at the intersections with the tilted lines.     

The Effects of Gender,Education, and Personal Skills Self-Confidence on Income in Business Management

A pay disparity between men and women persists,especially in the higher echelons of the business world.This study investigates whether salaries in the businessmanagement field are affected by gender, hours worked, SAT score, college selectivity,college grades, an undergraduate degree in business,graduate degree attainment, leadership self-confidence,and social self-confidence. The sample consists of 941 men and women employed in businessmanagement; approximately 8% of this group are racialminority members. As anticipated, hours worked, collegeselectivity, college grades, a graduate degree, and leadership self-confidence are determinants ofincome. Most important is the finding that aftercontrolling for hours worked, education background, andself-confidence in personal skills, men still receive higher salaries than women.     

Experimental evaluation of a modular approach to mobilizing antitobacco influences of peers and parents

The experimental evaluation of two components of a community intervention to prevent adolescent tobacco use are described. Youth antitobacco activities (e.g., peer quizzes, sidewalk art, poster and T-shirt giveaways, etc.) and family communications activities (pamphlets to parents and student quizzes of parents) were evaluated in two time-series experiments, each of which was conducted in two experimental and one control community. Students in Grades 6 and 8 and their parents were assessed in a series of four phone surveys in the first experiment and six phone surveys in the second. Implementation of the youth antitobacco and family communications activities led to significantly greater exposure of young people to antitobacco information. They led to increases in parent and youth knowledge about tobacco use and more negative attitudes toward tobacco. In Experiment 2, youths in intervention communities had significantly lower rated intentions to smoke. The findings suggest the value of a modular approach to community interventions for influencing the social context relevant to the onset of adolescent tobacco use.     

ANOTHER LOOK AT THE EFFECTS OF APPEARANCE, GENDER, AND JOB TYPE ON PERFORMANCE-BASED DECISIONS

The present study attempted to replicate and extend Heilman and Stopeck's (1985a) Lack of Fit Model. Using the Lack of Fit Model's proposal that attractiveness enhances perceived gender characteristics, we examined the effects of attractiveness and performance evaluations of persons in jobs rated as masculine, feminine, and neutral. Results were not consistent with the Model and did not replicate the results of the earlier study. Instead, attractiveness emerged as an asset regardless of job type or gender of employee. Attractive men and women were given higher overall ratings in all three jobs. In addition, attractive ratings were related to masculinity–femininity ratings. These findings are discussed in light of demographic and attitudinal changes in the workplace.     

Antecedents of toddler gender segregation: Cognitive consonance,gender-typed toy preferences and behavioral compatibility

This study examined 3 possible antecedents of toddler gender segregation: segregating children were hypothesized to exhibit more gender awareness, gender-typed toy preferences, and gender-typed compatible play styles than their non-segregating peers. Fifty-seven, primarily White, toddlers (28 males, 29 females) with a mean age of 35 months were observed in free play to determine their degree of same-gender peer preferences and gender-typed toy preferences. Teacher ratings of the children's play styles, and the children's knowledge of gender identity, and gender role awareness were also examined. Forty-two (21% of males and 62% of females) children played with same-gender peers at above chance levels during free play, with more girls segregating than boys. There were no differences between gender segregating and non-segregating children regarding gender-typed toy preferences or gender awareness. There were differences in teachers' ratings such that the gender segregating girls were seen as the most socially sensitive, and gender segregating boys were seen as more active and disruptive then the other children. These findings are interpreted as providing support for the compatible play style explanation of gender segregation, but the gender awareness and gender-typed toy preference hypotheses were not supported.This research was partially supported by grants from the Social Sciences and Humanities Research Counsel of Canada and the Fonds Pour la Formation de Chercheures et L'aide a la Recherche of the Ministry of Education of Quebec.The authors would like to thank the staff, students and parents of the Rainbow Preschool and the St. Andrews Preschool for their cooperation, and also, Judi Gulko, Wendy Seifert, Lisa Bedard, Sharon McKeown, Ina Grey, Lorrie Sippola, and Ivan Fernandez for their help in collecting and coding the data. Kim Powlishta also provided helpful insights regarding statistical analyses. Also, we would like to thank the anonymous reviewer for helpful comments.     

Predicting interpersonal competence in young adulthood: The roles of family,self, and peer systems during adolescence

The present investigation examines the impact of family, self, and peer systems, evaluated during early adolescence, on the development of interpersonal competence in young adulthood. The participants were 110 Caucasian individuals, their mothers, and one of their teachers. At the first assessment, the participants ranged in age from 11.5 to 15.1 years old. Approximately six years later, the participants completed a second evaluation involving assessment of interpersonal competence. Increased interparental conflict and parental divorce predicted decreased self-esteem. Decreased self-esteem predicted poorer peer-adolescent relationships, which, in turn, forecasted poorer adult interpersonal competence. The results suggest that living in a distressed family leads to diminished self-esteem which can influence the quality of peer relationships and place an adolescent on a trejectory toward difficulties in interpersonal competence during adulthood.