Acetylcholine release in the hippocampus and prelimbic cortex during acquisition of a socially transmitted food preference

Interference with cholinergic functions in hippocampus and prefrontal cortex impairs learning and memory for social transmission of food preference, suggesting that acetylcholine (ACh) release in the two brain regions may be important for acquiring the food preference. This experiment examined release of ACh in the hippocampus and prefrontal cortex of rats during training for social transmission of food preference. After demonstrator rats ate a food with novel flavor and odor, a social transmission of food preference group of rats was allowed to interact with the demonstrators for 30 min, while in vivo microdialysis collected samples for later measurement of ACh release with HPLC methods. A social control group observed a demonstrator that had eaten food without novel flavor and odor. An odor control group was allowed to smell but not ingest food with novel odor. Rats in the social transmission but not control groups preferred the novel food on a trial 48 h later. ACh release in prefrontal cortex, with probes that primarily sampled prelimbic cortex, did not increase during acquisition of the social transmission of food preference, suggesting that training-initiated release of ACh in prelimbic cortex is not necessary for acquisition of the food preference. In contrast, ACh release in the hippocampus increased substantially (200%) upon exposure to a rat that had eaten the novel food. Release in the hippocampus increased significantly less (25%) upon exposure to a rat that had eaten normal food and did not increase significantly in the rats exposed to the novel odor; ACh release in the social transmission group was significantly greater than that of the either of the control groups. Thus, ACh release in the hippocampus but not prelimbic cortex distinguished well the social transmission vs. control conditions, suggesting that cholinergic mechanisms in the hippocampus but not prelimbic cortex are important for acquiring a socially transmitted food preference.     

Visuospatial attention in schizophrenia: deficits in broad monitoring

Although selective attention is thought to be impaired in people with schizophrenia (PSZ), prior research has found no deficit in the ability to select one location and withdraw attention from another. PSZ and healthy control subjects (HCS) performed a stimulus detection task in which one, two, or all four peripheral target locations were cued. When one or two locations were cued, both PSZ and HCS responded faster when the target appeared at a cued than uncued location. However, increases in the number of validly cued locations had much more deleterious effects on performance for PSZ than HCS, especially for targets of low contrast whose detection was more dependent on attention. PSZ also responded more slowly in trials with four cued locations relative to trials with one or two invalidly cued locations. Thus, visuospatial attention deficits in schizophrenia arise when broad monitoring is required rather than when attention must be focused narrowly.     

When does event valence affect unrealistic optimism?

"Unrealistic optimism" (UO) has been found to be greater for negative (i.e. undesirable) than for positive (i.e. desirable) events. In two studies, we tested whether this "valence effect" is explicable in terms of motivational processes. In each case, participants were students (n = 159 in Study 1, n = 90 in Study 2), UO for the same health event was measured, and valence was manipulated by framing the event either negatively or positively. The degree to which the event would be expected to evoke concern was varied by manipulating the ease with which it could be avoided (Study 1) or the severity of its consequences (Study 2). A similar pattern of results was found in each study: the valence effect was exhibited in the condition where the event would have evoked concern, but not in the condition where it would have evoked little concern. The findings are in accord with an explanation of the valence effect in motivational terms. Implications for health education are discussed.     

Gender differences in children's divergent thinking

Block's theory (1984) of gender differences was examined to determine if it could explain inconsistencies in the reports of gender differences and the personality correlates of creativity in children. Additionally, an investigation of 244 gifted children in grades 4 to 8 is described. Two divergent thinking tests, each with a familiar and an unfamiliar item, were used to test cognitive style. The Dependency Proneness Test was used to measure independence, and the Fundamental Interpersonal Relations Orientation‐Behavior Children was used to measure social orientation. No gender differences were found on the measures of personality and cognitive style, and no significant association was found between cognitive style and personality. The results were discussed in light of the moderating influence of sex‐role flexibility and the relative freedom boys and girls experience in peer groups and play.     

PTSD Symptom Severity and Family Adjustment Among Female Vietnam Veterans

This study examined relations between posttraumatic stress disorder (PTSD) symptom severity and several family adjustment variables among a sample of 89 female Vietnam veterans and their male relationship partners. Findings revealed associations between PTSD symptom severity and measures of marital adjustment, family adaptability, family cohesion, parenting satisfaction, and psychological abuse. Results suggest that the presence of PTSD symptomatology may have important implications with regard to the family life of female Vietnam veterans.     

Opposites Do Not Attract: Social Status and Behavioral-Style Concordances and Discordances Among Children and the Peers Who Like or Dislike Them

Homophily, a term used to describe the tendency to associate with similar others, serves as a basis for attraction among children. The converse may also be true. Dissimilarity appears to contribute to dislike. In one of the only published studies to examine homophily and its converse, D. W. Nangle, C. A. Erdley, and J. A. Gold (1996) found that children were liked by peers who were similar to them in social status and behavioral style and disliked by peers who were dissimilar to them in social status and behavioral style. Examining gender influences, we were only able to partially replicate their findings in the present study. That is, evidence of homophily was found only for girls. In contrast, dissimilarity contributed to dislike for both genders, but was especially evident for boys. With respect to age, prosocial behavior appeared to have a more positive valence among younger girls. whereas aggressive behavior appeared to have a more negative valence among older boys. Attempts to reconcile these findings with those of the Nangle et al. (1996) investigation and the implications for understanding peer processes, gender influences, and behavior problems are discussed.     

Impaired control of visual attention in schizophrenia

To investigate attentional impairment in schizophrenia, the authors examined the performance of 22 patients with schizophrenia and 16 healthy control subjects in 4 visual search tasks that varied in perceptual requirements and in the need for precise attentional control. The rate of search was slowed in the patients in all tasks. However, the degree of slowing was largest in tasks requiring precise attentional control and smallest in tasks that were perceptually difficult but required less attentional control. This pattern of results indicates that the primary impairment of attention in schizophrenia lies in the control of attention and not in the selection processes that operate once attention has been directed to an object.     

An investigation of the psychological effects of the September 11, 2001, attacks on New York City: developing and implementing research in the acute postdisaster period

The September 11, 2001, attack on New York City was the largest human-made disaster in United States history. In the first few days after the attack, it became clear that the scope of the attacks (including loss of life, property damage, and financial strain) was unprecedented and that the attacks could result in substantial psychological sequelae in the city population. Researchers at the Center for Urban Epidemiologic Studies at the New York Academy of Medicine designed and implemented an assessment of the mental health of New Yorkers 5-8 weeks after the attacks. To implement this research in the immediate postdisaster period, researchers at the center had to develop, in a compressed time interval, new academic collaborations, links with potential funders, and unique safeguards for study respondents who may have been suffering from acute psychological distress. Results of the assessment contributed to a New York state mental health needs assessment that secured Federal Emergency Management Agency funding for mental health programs in New York City. This experience suggests that mechanisms should be in place for rapid implementation of mental health assessments after disasters.