Brain Gene Expression During REM Sleep Depends on Prior Waking Experience

In most mammalian species studied, two distinct and successive phases of sleep, slow wave (SW), and rapid eye movement (REM), can be recognized on the basis of their EEG profiles and associated behaviors. Both phases have been implicated in the offline sensorimotor processing of daytime events, but the molecular mechanisms remain elusive. We studied brain expression of the plasticity-associated immediate-early gene (IEG) zif-268 during SW and REM sleep in rats exposed to rich sensorimotor experience in the preceding waking period. Whereas nonexposed controls show generalized zif-268 down-regulation during SW and REM sleep, zif-268 is upregulated during REM sleep in the cerebral cortex and the hippocampus of exposed animals. We suggest that this phenomenon represents a window of increased neuronal plasticity during REM sleep that follows enriched waking experience.     

The semantic side of decision making

The research reported in this paper follows the perspective that decision making is a meaningful act that conveys information. Furthermore, the potential meanings associated with decision options may affect the decisions themselves. This idea is examined in the contexts of compensation, donation, and exchange. In general, judgments were relation dependent and meaning dependent. Furthermore, the results show nonmonotonicities and limited substitutability in a pattern that challenges straightforward ways of mapping decisions onto a common currency of utility.     

Further evidence for feature correlations in semantic memory.

The role of feature correlations in semantic memory is a central issue in conceptual representation. In two versions of the feature verification task, participants were faster to verify that a feature (< is juicy >) is part of a concept (grapefruit) if it is strongly rather than weakly intercorrelated with the other features of that concept. Contrasting interactions between feature correlations and SOA were found when the concept versus the feature was presented first. An attractor network model of word meaning that naturally learns and uses feature correlations predicted those interactions. This research provides further evidence that semantic memory includes implicitly learned statistical knowledge of feature relationships, in contrast to theories such as spreading activation networks, in which feature correlations play no role.     

A computer-controlled olfactometer for fMRI and electrophysiological studies of olfaction

A design for an inexpensive and reliable olfactometer is presented. The design has several advantages for fMRI and electrophysiology investigators. These advantages include relatively rapid odorant rise times, computer control, multiple odor administration, and no ferrous materials near the subjects. In addition, the device is contamination resistant, and, because the air is neither warmed nor humidified, it is unlikely to become an incubator for bacteria. The olfactometer is constructed of off-the-shelf chromatography parts that require little modification.     

Assessing the patterns that prevent teenage pregnancy

Adolescence is a time of rapid developmental change and emotional upheaval as teenagers strive to assert their autonomy. In a similar vein, pregnancy--even under optimal circumstances with an adult mother--has been labelled a developmental crisis. Pregnancy during the teenage years has a synergistic effect, magnifying maturational changes in both the teenage girl and her infant. Recommended intervention strategies in cases of adolescent pregnancy should address not only the imminent mother-infant relationship, but the dyad's future transformations. One intervention technique is previewing, which is derived from the rhythms of adaptive exchange between mature mothers and their infants. The aim of previewing with adolescent parents is to help the teenager become more attuned to the infant's imminent developmental skills and to heighten their rapport.     

Parent-daughter discussions to discourage tobacco use: feasibility and content.

Parents engaged their 6th- and 8th-grade daughters in a conversation about tobacco. The parents were guided by a pamphlet designed to encourage effective family communication about tobacco. Conversations were audiotaped for later coding. Evidence is presented that such parent-daughter conversations about tobacco use can be successfully carried out in a nonaversive manner. Overall, the conversations were perceived to have gone well, with very little conflict reported. Further, the daughters reported that the parental advice was helpful and they did not resist receiving such advice. Among the topics suggested by the pamphlet, the following were most frequently discussed: consequences of smoking as experienced by friends and relatives, difficulty of quitting, promotional tactics of tobacco companies, making rules about tobacco use, and deciding on the consequences of rules adherence or violation. Other frequently discussed topics, which were not covered in the pamphlet, may also be appropriate for parent-daughter conversations: diminished physical attractiveness and body-image issues, how to resist peer pressure, and health risks.     

Migrant labor in South Africa: a comparative analysis of the academic achievement of father-present and father-absent adolescents

This study was designed to determine whether there are significant differences in academic achievement between father-present and father-absent (due to migrant labor) adolescents. Data were collected from 276 high school students in South Africa. Academic achievement was measured by the Human Sciences Research Council's (HSRC) Scholastic Achievement Test, covering biology, English (second language), and mathematics. Father-present students were found to score significantly higher than father-absent students. The findings suggest that a father's absence due to work conditions has deleterious effects on the scholastic performance of young people.     

Racism as a stressor for African Americans. A biopsychosocial model.

Various authors have noted that interethnic group and intraethnic group racism are significant stressors for many African Americans. As such, intergroup and intragroup racism may play a role in the high rates of morbidity and mortality in this population. Yet, although scientific examinations of the effects of stress have proliferated, few researchers have explored the psychological, social, and physiological effects of perceived racism among African Americans. The purpose of this article was to outline a biopsychosocial model for perceived racism as a guide for future research. The first section of this article provides a brief overview of how racism has been conceptualized in the scientific literature. The second section reviews research exploring the existence of intergroup and intragroup racism. A contextual model for systematic studies of the biopsychosocial effects of perceived racism is then presented, along with recommendations for future research.     

Variables affecting racial-identity salience among African Americans

The author clarified the African American racial-group identification process by addressing the issue of salience and its relationship to racial-group attitudes. A sample of 409 African American adults responded to surveys pertaining to their racial-group salience, racial-group attitudes, racial socialization, racial-group interaction, political activism, experiences of discrimination, and demographic data (e.g., sex, age, and income). The author tested 3 hypotheses: (a) Racial socialization and interaction with other African Americans are predictive of African American racial-identity salience; (b) discriminatory experiences are predictive of African American racial-identity salience; and (c) racial-identity salience is a stronger predictor of African American racial-group identification than are previously identified predictive variables (D. H. Demo & H. Hughes, 1990; V. L. Thompson Sanders, 1991, 1995). The results supported the 1st and 3rd hypotheses.     

Further validation of social impairment as a predictor of substance use disorders: findings from a sample of siblings of boys with and without ADHD.

Examined predictors of substance use disorders in nonreferred siblings of boys with and without attention deficit hyperactivity disorder to further investigate whether previous findings documenting the role of social impairment in predicting substance use disorders would be replicated. Participants were comprehensively assessed at Time 1 and at 4-year follow-up. We found that social impairment was the sole significant predictor of alcohol and substance abuse and smoking after controlling for other variables previously shown to be predictors of substance use disorders. These results confirmed prior findings documenting the critical role of social impairment in predicting later substance use disorders.