Evidence for independent processing of subjective contour brightness and sharpness.

Subjective contours have been of considerable interest because of their importance to theories and physiological models of form perception. In particular, they have recently been characterized as the result of magnocellular cortical processing. There is, however, a paucity of parametric data relating to basic psychophysical parameters in this field. Two experiments are reported in which the roles of subjective contour size, retinal eccentricity, and flicker rate in subjective contour salience were investigated. Eleven observers estimated subjective contour magnitude using an Ehrenstein configuration. Configurations ranging in size from 0.25 to 3 deg were presented to three retinal loci (fovea, 2 deg, and 4 deg) at flicker rates ranging from 5 to 15 Hz. Subjective contour brightness and distinctness were measured separately. Brightness was greatest at a subjective contour size of about 1.25 deg, at flicker rates of 5-7 Hz, and at 3 deg peripheral for all flicker rates and all but the smallest stimulus sizes. Distinctness decreased with eccentricity and flicker, but remained high at small diameters (thus implicating spatially sensitive mechanisms). Taken together, the results support a magnocellular processing of subjective contours with respect to brightness, but also suggest that there is a parvocellular contribution to subjective contour sharpness.     

Postdeployment Suicide Risk Increases Over a 6‐month Period: Predictors of Increased Risk among Midwestern Army National Guard Soldiers

National Guard (NG) soldiers returning from deployments in Iraq and Afghanistan were surveyed at 6 and 12 months following their return (N = 970). The overall prevalence of suicide risk at 6 and 12 months following their return was assessed, as were changes in suicide risk among soldiers initially at high or low risk. Factors associated with changes in risk were assessed. The percentage of NG soldiers with high suicide risk increased from 6.8% at 6 months to 9.2% at 12 months (odds ratio = 1.7, p = .02). In the 882 soldiers initially at low risk, 5.9% (52/882) became high risk at 12 months; in the 64 soldiers initially at high risk, 46.9% (30/64) became low risk at 12 months. Initial levels of depressive symptoms were predictive of changing to high risk; this association appeared to be partially explained by soldier reports of increased search in the meaning in life and higher levels of perceived stress. Because suicide risk increases over the first 12 months, continued risk assessments during this time period should be considered. Supporting soldiers to find meaning in their life after deployment and enhancing their capacity to cope with perceived stress may help prevent increases in suicide risk over time.     

Distress, personality, and mammography utilization among women with a family history of breast cancer.

The authors examined the impact of psychological distress and the personality construct of conscientiousness (as measured by the Neuroticism, Extraversion, and Openness-Five Factor Inventory) on mammography utilization among women who were at increased risk for breast cancer. Participants were 200 women who had at least 1 first degree relative with breast cancer. Overall, 80% of the participants had obtained a mammogram in the previous year. Analyses controlling for potential confounders (perceived risk, decisional balance, and physician recommendation for mammography), revealed that distress was negatively associated with mammography utilization among participants who were low in conscientiousness. Distress was not significantly related to mammography utilization among highly conscientious women. The results are discussed in terms of their implications regarding interventions designed to increase mammography utilization in this population.