Regional cerebral blood flow response to recognition memory versus semantic classification tasks

Two randomly assigned groups, N = 7 each, of neurologically normal patients were composed. One group, RM, had regional cerebral blood flow measurements during a recognition memory probe test; the other group, SC, had rCBF measurements during a semantic classification task, using the same stimulus and response features as the RM task. Thus, the groups differed only in the cognitive instruction they were executing. The RM group showed a significantly lower change from resting baseline to activation, in mean left hemisphere initial slope index, than did the SC group. The RM group, but not the SC group, showed a significant inverse correlation between occipital flow and accuracy of memory performance as indicated by d′. Correlations between age and hemispheric initial slope index, and between homologous left and right hemisphere sites, were also described. The results are considered to support an anatomical basis for the distinction between episodic and semantic memory and to suggest that occipital flow may diminish with accurate memory performance because of an upstream demand of blood in the medial temporal lobes.     

The ecological approach to perceiving as a foundation for understanding the development of knowing in infancy

The ecological thesis of direct realism is used as a framework for examining the development of knowing in human infancy. When information for perceiving is defined ecologically (i.e., relative to the situational context and to the physical dimensions, capabilities, and needs of the perceiver), knowing need not be construed as the act of using representations to give meaning to acts or percepts. Knowing, alternatively, is the act of noticing affordances, situation and perceiverspecific meanings of objects, according to their value to the perceiver for achieving specific goals. Changes with development in infant sensorimotor functioning may, in this view, be explained by a process of increasing economy in noticing potentially available affordances, rather than a process of constructing a representational system for making present something not present. Studies of three infant skills widely attributed to the onset of representation are examined with regard to this ecological thesis. Results indicate that the noticing of affordances is critically involved in each of these skills.     

Exposure to pornography,permissive and nonpermissive cues,and male aggression toward females

The present study examined the role of permissive and nonpermissive cues in mediating the relationship between exposure to erotica and aggression. Male subjects viewed either neutral slides with a silent female or erotic slides with a female who made permissive, nonpermissive, or no comments about the slides. The males rated the slides and subsequently rated the female confederate. Male subjects were then given an opportunity to administer their choice of several intensities of shock to the female in a competitive reaction-time task. Subjects in the permissive cues condition rated the erotic slides as more arousing, saw the female as more reasonable and accepting, and selected more intense shocks for the female than did subjects in the other conditions. One explanation of these results is that permissive cues in the presence of erotica led the male to believe that other normally inappropriate behaviors would be tolerated.     

Factor influencing suicide intent in gay and bisexual suicide ideators: differing models for men with and without human immunodeficiency virus.

Of 778 gay and bisexual men (none with acquired immunodeficiency syndrome [AIDS]), 27% (n = 212) reported suicidal ideation over the previous 6 months. Covariance structure models were used to explore predictors of suicide intent among (n = 112) suicide ideators with (n = 100) and without (n = 112) human immunodeficiency virus (HIV). Current AIDS-related stressors (deaths and illnesses and perceived AIDS risk) and past levels of adaptive functioning (social isolation and depression) were significantly more powerful predictors of suicide intent among HIV-positive than among HIV-negative ideators. Biological AIDS risk predicted neither suicide intent, current distress, nor perceived AIDS risk. Pathways to suicide intent appear to be psychologically, rather than biologically, mediated. Among HIV-positive ideators, AIDS-related death and illness events predicted suicide intent but not current distress symptoms. Some suicidal ideation in response to AIDS-related events may be an effort to cope rather than a manifestation of psychological distress.     

Asymmetrical effects of positive and negative events: the mobilization-minimization hypothesis

Negative (adverse or threatening) events evoke strong and rapid physiological, cognitive, emotional, and social responses. This mobilization of the organism is followed by physiological, cognitive, and behavioral responses that damp down, minimize, and even erase the impact of that event. This pattern of mobilization-minimization appears to be greater for negative events than for neutral or positive events. Theoretical accounts of this response pattern are reviewed. It is concluded that no single theoretical mechanism can explain the mobilization-minimization pattern, but that a family of integrated process models, encompassing different classes of responses, may account for this pattern of parallel but disparately caused effects.     

AIDS-related factors predictive of suicidal ideation of low and high intent among gay and bisexual men.

AIDS-related stressors were studied in relationship to suicidal ideation and suicide intent among 778 gay and bisexual men (none with AIDS). Over the previous six months, 27% (n = 212) reported suicidal ideation. Subjects who reported suicidal ideation (compared to those who did not) were more likely to report recent (last 6 months) bereavement of partner, recent ARC diagnosis, and multiple close friends with ARC. Suicide ideators were divided by a median split on a self-report scale of suicide intent into low (n = 105) and high (n = 107) intent suicide ideators. News of HIV seropositivity was specifically related to low intent suicidal ideation. High intent suicidal ideation was associated with having a partner with AIDS or ARC, or multiple close friends with AIDS, or having ARC. Generally speaking, while temporally discrete AIDS-related events were associated the report of suicidal ideation, ongoing stressors which may more greatly challenge adaptational capacities were more associated with high intent suicidal ideation.