Attenuation of Hippocampal 11beta-Hydroxysteroid Dehydrogenase Type 1 by Chronic Psychosocial Stress in the Tree Shrew

11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD-1) catalyses the interconversion of active cortisol and corticosterone with inert cortisone and 11-dehydrocorticosterone, thus regulating glucocorticoid access to intracellular receptors. In rats, chronic glucocorticoid excess or stress increases 11beta-HSD-1 in the hippocampus, producing suggestions that it may attenuate the deleterious effects of chronic glucocorticoid excess. However, 11beta-HSD-1 predominantly catalyses 11beta-reduction in the intact liver and hippocampal cells, thus regenerating active glucocorticoids from inert substrate. We studied 11beta-HSD activity in the tissues of male tree shrews following 28 days of sustained psychosocial stress or exogenous administration of cortisol. In the hippocampus, chronic psychosocial stress attenuated 11-HSD-1 activity (69 +/- 9% of control), whereas cortisol alone had no effect. In the liver, both chronic stress and cortisol administration decreased 11beta-HSD-1 activity (47 +/- 11% and 49 +/- 4% fall, resp.). Attenuation of 11beta-HSD-1 within tissues may reflect a homeostatic mechanism designed to minimise the adverse effects of prolonged stress and/or glucocorticoid excess.     

Additive effects of inhibiting attention to objects and locations in three-dimensional displays

One of the processes thought to underlie visual selection works by biasing attention away from either recently examined locations or objects. The extent of this “inhibition” is greatest when the inhibited object and the inhibited location coincide. In Experiment 1, rectangles are presented stereoscopically at different depths but at similar positions horizontally and vertically. Here, any inhibition should be based solely on a spatial code, as the objects, the rectangles are clearly separate objects. In Experiment 2, the corners of the rectangles are joined to produce a single cuboid that extends in depth space. Now inhibition based on both spatial and object codes should be seen because even when on different depth planes the cue and target are associated with the same object. Consistent with our understanding of the additive effects of inhibition of space and object codes, the extent of inhibition in the second study is almost double that of the first. The results further suggest that space-based inhibition operates within a two-dimensional representation while object-based inhibition utilizes a three-dimensional representation.     

Support Groups for Suicide Survivors: Results of a Survey of Group Leaders

To update and expand Rubey and McIntosh's (1996) survivors of suicide support groups report, SPAN USA completed a survey of U.S. support group leaders (n = 100; 24% completion). There are now more survivor groups (from 280 to 417), and the majority of groups now have a survivor leader (78% vs. 25%). Groups continue to be small (88% < 10 members per session) and meet on a monthly basis (55%). Sharing continues to be a universal experience in groups, which tend to be open‐ended (85%). Current groups are newer, and more operate without a sponsor. Further research is needed to examine group member perspectives and effectiveness of groups.     

Youth Media Lifestyles

In this article, the concept of “media lifestyles” is adopted in order to develop a comprehensive approach toward youth engagement in communication media. We explore how 503 Dutch eighth grade students with full access to new technology combine a broad range of media by focusing on their engagement with media while taking various contexts of use into account. Four different media lifestyles of media omnivores, networkers, gamers, and low‐frequency users are described. Furthermore, we show how the methodology we used is able to provide more insight into how the distinguished media lifestyles were codetermined by particular media, functions and social contexts. Finally, the implications for the Uses & Gratifications theory are discussed.     

Influence of hand position on the near effect in 3-D attention

Voluntary reorienting of attention in real depth situations is characterized by an attentional bias to locations nearer the viewer once attention is deployed to a spatially cued object in depth. Previously, this effect (initially referred to as the near effect) was attributed to access of a 3-D viewer-centered spatial representation for guiding attention in 3-D space. The aim of this study was to investigate whether the near effect could have been associated with the position of the response hand, which was always near the viewer in previous studies that investigated endogenous attentional shifts in real depth. In Experiment 1, the response hand was placed at either the near or far target depth in a depth-cuing task. Placing the response hand at the far target depth abolished the near effect, but failed to bias spatial attention to the far location. Experiment 2 showed that the response hand effect was not modulated by the presence of an additional (passive) hand, whereas Experiment 3 confirmed that attentional prioritization of the passive hand was not masked by the influence of the responding hand on spatial attention in Experiment 2. The pattern of results is most consistent with the idea that response preparation can modulate spatial attention within a 3-D viewer-centered spatial representation.