Dec. 16, 2008 -- Older people may be less likely to remember emotionally negative things because the brain works differently as it ages, according to a new study.

A new study used brain imaging technology to see how participants' brains were working when they were exposed to images -- some negative and some neutral. While in the MRI (magnetic resonance imaging) machine, participants ranked each image on a pleasantness scale. Negative images included things like mutilated bodies and attacking snakes.

Participants were later asked to recall the images. Neuroscientists looked at how the brain reacted during exposure to the images -- and then examined how that brain activity correlated with recall.

Half of the 30 participants were young (average age 24) and half were old (average age 70). All were women. The study was published in Psychological Science.

Researchers from the Duke University Medical Center found that younger women were more likely than older women to recall negative images. In both groups, there was greater memory of negative images than neutral images.

Although memory of negative images was linked to activity in the brain region involved in emotional memory (the amygdala), there were differences in the connectivity between the two age groups.

Older adults had more connectivity of the right amygdala; the younger group had more of the left amygdala. Older adults also has less connectivity between the amygdala and other memory areas of the brain such as the hippocampus, but increased connectivity with a different area of the brain.

"Perhaps at different stages of life, there are different brain strategies," Roberto Cabeza, senior author and Duke professor in the Center for Cognitive Neuroscience, says in a news release. "Younger adults might need to keep an accurate memory for both positive and negative information in the world. Older people dwell in a world with a lot of negatives, so perhaps they have learned to reduce the impact of negative information and remember in a different way."