The Relationship of Drug Use to Suicide Ideation and Attempts Among African American,Hispanic, and White Non-Hispanic Male Adolescents

This study presents self-report cross-sectional and longitudinal data on associations between drug use, suicide ideation, and attempts in a multiethnic sample of seventh- and eighth-grade male adolescents attending school in the greater Miami, Florida, area. African Americans had the highest prevalence of 6-month ideation (20.5%), and Haitians had the highest attempts (11.4%). For the total sample, tranquilizers had the highest odds ratio for ideation (3.4), and PCP for attempts (6.2). Psychoactive drug-use was consistently related to attempts among Hispanics, white non-Hispanics, and African Americans. Acculturation strains interacted with cocaine and crack to predict suicide attempts among Hispanic respondents.     

Work Performance and the Achievement—Strivings and Impatience—Irritability Dimensions of Type A Behaviour

On propose dans cette étude un modfèle selon lequel les efforts en vue de la réussite et les dimensions impatience-irritabilité du comportement de type A prédisent directement et/ou indirectement la performance au travail. Dans un échantillon de 92 hommes et de 69 femmes (âge moyen: 30 ans), les efforts en vue de la réussite sont tenus de prédire la performance professionnelle directement et par l'intermédiaire de leur action positive sur la concentration. On suppose que l'impatience-irritabilité va détériorer la santé; et tout problème de santé devrait influencer négativement la concentration. On a recueilli, pour apprécier la performance au travail, à la fois des auto-évaluations et celles du contremaître. Une analyse taxinomique a fortement corroboré le modèle retenu bien que la liaison indirecte entre les efforts en vue de la réussite et les évaluations de la performance par le contremaître ne soit pas statistiquement significative.
In this study, a model is proposed whereby the achievement-strivings and impatience–irritability dimensions of Type A behaviour predict work performance directly and/or indirectly. In a sample of 92 males and 69 females ( M age = 30 years), achievement strivings are held to predict work performance directly and through their positive effects on concentration. impatience–irritability is predicted to negatively influence health; and any health problems are predicted to negatively influence concentration. Both self- and supervisor ratings of work performance were obtained. Path analyses provided strong support for the proposed model, although the direct link between achievement strivings and supervisor ratings of performance was not statistically significant.     

Learned irrelevance and retrospective correlation learning

In 1973 Mackintosh reported an interference effect that he called learned irrelevance in which exposure to uncorrelated (CS/US) presentation of the unconditional stimulus (US) and the conditioned stimulus (CS) interfered with future Pavlovian conditioning. It has been argued that there is no specific interference effect in learned irrelevance; rather the interference is the sum of independent CS and US exposure effects (CS + US). We review previous research on this question and report two new experiments. We conclude that learned irrelevance is a consequence of a contingency learning and a specific learned irrelevance mechanism. Moreover even the “independent exposure controls”, used in previous experiments to support the CS and US exposure account, provide support for the correlation learning process.     

Rapid discrimination of McCollough effects.

The McCollough effect is a colour aftereffect that is contingent on pattern orientation. Three experiments were conducted to establish whether such aftereffect colours could serve as a basis for discrimination in several rapid discrimination tasks. In the first experiment it was investigated whether aftereffect colours could act like a simple 'feature' in a visual search task involving a difficult orientation discrimination. Without McCollough adaptation, the time taken to detect a 'target' among 'distractors' increased substantially as the number of distractors increased. With adaptation, detection time was essentially independent of the number of distractors, indicating that the nature of the task changed from a difficult orientation discrimination to a simple discrimination based on differences in aftereffect colours. The second and third experiments employed a difficult four-alternative forced-choice procedure in which subjects were required to discriminate a monochromatic patch of square-wave grating oriented at 45 degrees from three others oriented at 135 degrees (and vice versa). The gratings were presented very briefly (67-333 ms) followed by a 500 ms mask. Subjects performed the task with and without McCollough adaptation. Performance was strikingly better after adaptation: colour aftereffects could be used to make the discrimination even at exposure durations as short as 67 ms. The third experiment demonstrated that this enhanced performance was indeed due to perceived colour differences (rather than a possible contrast difference). The results of the three experiments are discussed in relation to proposals about the locus of the McCollough effect.