Correlates of virtual navigation performance in older adults.

Despite considerable evidence for deleterious effects of aging on place learning and memory, less is known about the trajectory and the putative neural mechanisms of these decrements. The virtual Morris water task (vMWT) is a human analog of a nonhuman spatial navigation task. The present study investigated longitudinal changes in place learning in 51 healthy, nondemented adults (age 30-83 years) who completed the vMWT and a neuropsychological battery at 2 time-points (interval = ∼8 years). We also assessed cross-sectional associations between vMWT and brain structure, biochemical integrity, and standardized neuropsychological measures in a subset of 22 individuals who underwent magnetic resonance imaging at follow-up. Despite no longitudinal decrement in vMWT performance, there were cross-sectional age differences on the vMWT favoring younger adults. Negative associations were observed between vMWT latency and gray matter volumes in the right hippocampus, bilateral thalamus, and right medial orbitofrontal cortex and between vMWT latency and white matter fractional anisotropy in the bilateral uncinate fasciculus. Collectively, these results suggest a pattern of differences in the structural integrity of regions supporting successful navigation even in the absence of longitudinal performance decrements.

Contributions of sex, testosterone, and androgen receptor CAG repeat number to virtual Morris water maze performance.

The possibility that androgens contribute to the male advantage typically found on measures of spatial cognition has been investigated using a variety of approaches. To date, evidence to support the notion that androgens affect spatial cognition in healthy young adults is somewhat equivocal. The present study sought to clarify the association between testosterone (T) and spatial performance by extending measurements of androgenicity to include both measures of circulating T as well as an androgen receptor-specific genetic marker. The aims of this study were to assess the contributions of sex, T, and androgen receptor CAG repeat number (CAGr) on virtual Morris water task (vMWT) performance in a group of healthy young men and women. The hypothesis that men would outperform women on vMWT outcomes was supported. Results indicate that CAGr may interact with T to impact navigation performance and suggest that consideration of androgen receptor sensitivity is an important consideration in evaluating hormone-behavior relationships.

Brain activation patterns in women with acquired hypoactive sexual desire disorder and women with normal sexual function: a cross-sectional pilot study.

OBJECTIVE: To examine and compare brain activation patterns of premenopausal women with normal sexual function and those with hypoactive sexual desire disorder (HSDD) during viewing of validated sexually explicit film clips. DESIGN: Cross-sectional pilot study. SETTING: University-based clinical research center. PATIENT(S): Premenopausal women. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Areas of brain activation during viewing of sexually explicit film clips. RESULT(S): Women with normal sexual function showed significantly greater activation of the right thalamus, left insula, left precentral gyrus, and left parahippocampal gyrus in comparison with women with HSDD, who exhibited greater activation of the right medial frontal gyrus and left precuneus regions. CONCLUSION(S): Women with HSDD may have alterations in activation of limbic and cortical structures responsible for acquiring, encoding, and retrieving memory, the processing and memory of emotional reactions, and areas responsible for heightened attention to one's own physical state.

Sex differences and similarities in married couples: patterns across and within cultures.

In this study, we examined the patterns of sex differences in men and women married to each other in five cultures (China, Russia, Turkey, UK, and the U.S.) to look for universal patterns in behavioral dimorphisms and for cultural variability in those patterns. Over 400 couples in each cultural group completed the 235-item Marriage and Relationship Questionnaire on various aspects of marriage, appropriately translated for each culture. Sex differences were anticipated in responses related to female choosiness, labor performed, emotional expressiveness, interest in sex, physical attractiveness, and jealousy. To measure male-female differences in each culture, t-tests were utilized, and effect sizes were calculated. Significant sex differences (p < .05, two-tailed) emerged in all six areas examined, although cultural differences were also seen in the patterns. For example, on items relevant to female choosiness, women in most, but not all, cultures were more likely than their husbands to endorse these statements: "I have thought of divorcing my spouse" and "My parents played a role in choosing my spouse." In China, where scores on emotional expressiveness were low, sex differences disappeared in the category related to emotions. Results suggest that long-term marriage exhibits a balance between homogamy and dimorphism serving reproductive interests. Moreover, culture may moderate this balance for particular sex differences.

The relationship between second to fourth digit ratio, spatial cognition, and virtual navigation.

Studies in human and non-human animals have found that early life exposure to androgens may affect later spatial performance. Recent studies have suggested that the ratio of the second to fourth digit (2D:4D) may serve as an index of prenatal androgen exposure. Some studies have found that the 2D:4D ratio predicts adult spatial performance, although the nature of the relationship is equivocal. This study was designed to quantify the relationships between 2D:4D ratio, spatial cognition, and spatial navigation using a virtual Morris water task (vMWT) in a sample of young adult men and women (N = 140). The results replicated findings from the literature regarding sex differences in 2D:4D ratio, vMWT performance, and spatial cognition. However, 2D:4D ratio was not consistently related to spatial cognition or spatial navigation in men or women. Results were discussed within the framework of androgen influences on spatial cognition and the degree to which 2D:4D ratio serves as a marker for early life androgen exposure.