Web edition: June 29, 2012
Print edition: July 14, 2012; Vol.182 #1 (p. 15)
Good touch, bad touch
A leg caress can delight or feel totally skeevy, depending on who’s doing the caressing. A touch’s emotional baggage can be seen in the brain’s initial response to that touch, scientists report in the June 19 Proceedings of the National Academy of Sciences. Heterosexual men’s somatosensory cortices, brain regions that detect a touch’s basic attributes, responded differently when a touch was thought to come from a gorgeous woman in a black evening dress or a masculine man in a black tank top. Emotions are incorporated into touch sensation surprisingly early in the sensory process, the study shows.
Brain zap helps an aging memory, if you’re educated
Brain jolts improve working memory in older adults, but only in those who are highly educated. With age comes a growing number of working memory failures, such as walking into the kitchen and forgetting why. After a session of transcranial direct current stimulation, working memory improved for highly educated participants (schooled for 16.9 years on average). People with lower education levels (13.5 years) saw no benefit or grew worse. The results may reflect people using different strategies to solve problems, Marian Berryhill and Kevin Jones of the University of Nevada, Reno write in an upcoming Neuroscience Letters.
High-risk Alzheimer’s gene variant poses greater threat to women
A well-known risk factor for Alzheimer’s is particularly dangerous for older women even if they are healthy and sharp, researchers at Stanford University School of Medicine and colleagues report in the June 13 Journal of Neuroscience. Women with one copy of the e4 version of the ApoE gene had abnormal activity in key brain regions and elevated levels of the Alzheimer’s-related tau protein in spinal cord fluid compared with women who lacked that version of the gene. Men with one copy of e4 were less affected in those respects. The results may help explain why women are more susceptible to Alzheimer’s.