The statistical interaction of cerebral specialization and integration in the interpretation of dynamic brain images

Two constructs of brain function, namely cerebral specialization and integration, have been examined in the analysis of blood flow and metabolic function resulting from dynamic imaging procedures. The purpose of the current paper is to illustrate the interaction of these two constructs at the statistical level. Because of the statistical interaction, it is argued that the currently accepted statistical evidence for cerebral specialization is, in fact, partially a function of the degree of regional cerebral integration. Therefore, found asymmetries of flow or rate may be solely a function of cerebral integration. These points are discussed with respect to developing a better understanding of stimulus/brain/behavior relations.     

Evidence for genetic influences on personality from self-reports and informant ratings.

Self-report data on Extraversion (E) and Neuroticism (N), together with ratings by the co-twin, were obtained from a sample of 826 adult female twin pairs ascertained through a population-based twin register. Data were analyzed using a model that allowed for the contributions to personality ratings of the rater's personality (rater bias) as well as of the personality of the person being rated. For E, but not for N, significant rater bias was found, with extraverted respondents tending to underestimate, and introverted respondents tending to overestimate, the Extraversion of their co-twins. Good agreement between self-reports and ratings by the respondent's co-twin was found for both E and N. Substantial genetic influences were found for both personality traits, confirming findings from genetic studies of personality that have relief only on self-reports of respondents.     

Weight gain and withdrawal symptoms after smoking cessation: a preventive intervention using d-fenfluramine

Directly measured food intake in 31 overweight female smokers to test whether (a) calorie and carbohydrate intakes increase after smoking cessation and (b) double-blind d-fenfluramine (30 mg), a serotonin-releasing drug, suppresses weight gain, overeating, and dysphoric mood associated with stopping smoking. Placebo-treated patients grew dysphoric after smoking withdrawal and ate 300 kcal/day more from 2 to 28 days after, showing a 3.5-lb weight gain. Fat and protein intakes did not change, but carbohydrate intake increased (30% to 40%). D-fenfluramine prevented postcessation dysphoria. Although drug-treated patients ate more carbohydrate snacks just after quitting, they returned to baseline by 4 weeks, showing a 1.8-lb weight loss. Agents that enhance brain serotonin-mediated neurotransmission may help prevent weight gain, overeating, and dysphoric mood after smoking withdrawal.     

Is Justice Really Blind?–The Influence of Litigant Physical Attractiveness on Juridical Judgment1

The present investigation examined the influence of litigant physical attractiveness on the decisions of 91 undergraduates playing the role of nondeliberating jurors in an automobile negligence trial. Seeking to achieve a more realistic simulation of actual courtroom practice than that produced in prior studies, which have relied exclusively on short written synopses as their method of trial presentation, this experiment tested the hypothesis that physical attractiveness would have a significant impact on juridic judgments even though an audiovisual presentation of the trial permitted the introduction of a variety of other important stimuli typically present at a jury trial. This prediction received empirical support: Subjects exposed to an attractive plaintiff and an unattractive defendant more often found in favor of the plaintiff and awarded more money in damages than students viewing an unattractive plaintiff and an attractive defendant. However, in contrast to findings from general studies of interpersonal evaluation, analyses of student perceptions of the two litigants provided only limited evidence for a global (positive) physical attractiveness stereotype within the context of a simulated trial. Instead, the observed effect of physical attractiveness on student decisions was apparently mediated by differential perceptions of the seriousness of the accident itself. Possible implications of the results for the judicial process were mentioned.     

Of deadly beans and risky stocks: Political ideology and attitude formation via exploration depend on the nature of the attitude stimuli

An attitude formation task examined how conservatives and liberals explore information about novel stimuli and form attitudes towards them. When framed as the BeanFest game, conservatives sampled fewer beans and exhibited a stronger learning asymmetry (i.e., better learning for negative than positive beans) than liberals. This has been taken as strong evidence that conservatives are more sensitive to negative stimuli than liberals. We argue that the learning asymmetry and sampling bias by conservatives is due to framing of the game. In addition to the BeanFest, we framed the game as StockFest (i.e., a stock market game) where participants learned about novel stocks. We replicated the pronounced learning asymmetry for conservatives in the BeanFest game, but found a pronounced learning asymmetry for liberals in the StockFest game. We suggest that conservatives and liberals are equally sensitive to negative stimuli but in different domains.     

Is there any scapegoat around? Determinants of intergroup conflicts at different categorization levels.

Recategorization at a higher level reduces tensions between groups. However, recategorization may cause conflicts between the common in-group and a new out-group. Additionally, determinants of conflict between subgroups may enhance conflict at the higher categorization level. In the context of German unification, the authors explored these suggestions with an East German 3-wave longitudinal study and a West German control group. Results show that a salient East German versus West German categorization enhances conflict between subgroups, whereas categorization as German enhances conflict at the common in-group level. Determinants of subgroup conflict also influence conflict at the inclusive level (Germans and foreigners). Thus, recategorization is a 2-edged instrument: Although it reduces conflict at the subgroup level, it may initiate conflict at the common in-group level.