December 25, 2008
Aging brain lets negative memories fade
There's a scientific reason why older people tend to see the past through rose-colored glasses, Canadian researchers suggest -- negative memories tend to fade.
Study author Dr. Florin Dolcos of the University of Alberta in collaboration with colleagues at Duke University in Durham, N.C., identified brain activity that causes older adults to remember fewer negative events than their younger counterparts.
The researchers asked older and younger participants to rate the emotional content of pictures on a pleasantness scale, while their brain activity was monitored with a functional magnetic resonance imaging. Thirty minutes later, when participants were unexpectedly asked to recall the images, older participants remembered fewer negative images.
The older participants had reduced interactions between the amygdala, a part of the brain that detects emotions, and the hippocampus, the part of the brain involved in learning and memory, when shown negative images.
The study, published in the journal Psychological Science, found the brain scans showed older participants had increased interactions between the amygdala and the dorsolateral frontal cortex, a brain region involved in higher thinking processes, like controlling emotions. The older participants were using thinking rather than feeling processes to store these emotional memories, the study said.