A team of researchers from Duke University and University of Alberta took two groups of volunteers - one in their mid-20s, one in their 70s - and showed them photos that were either neutral or very negative, depicting such things as mutilated bodies or sick children. Later, the participants were unexpectedly asked to recall the images. The older group had a harder time recalling the negative images than the younger group, and brain scans revealed the differences in brain activity between the two groups.


The study - which points to possible ways to improve memory in aging adults - appears in the January issue of Psychological Science. Peggy St. Jacques, the Duke University graduate student in psychology and cognitive neuroscience who is the lead author, said there are primal reasons why seniors tend to take a dim view of unpleasant memories.

"As we age, we have a more limited perspective of the time we have left," she said, "so we may focus more on things that increase our emotional well-being."

And still other research has revealed that in brain scans the amygdala, the brain's emotion detector, lights up equally intensely in young and old while viewing positive events, yet does not light up as brightly or as long in older people when they view negative images.