Monday, December 22, 2008

Imaging Reveals Age-Related Memory Differences

In older adults, enhanced amygdala activity linked to memory of negative pictures was preserved

22 dec 2008-- Activity in the amygdala linked to subsequent memory of negative images was preserved in older adults, but older individuals had less subsequent-memory activity for negative pictures in visual cortices, according to research published in the January issue of Psychological Science.

Peggy L. St. Jacques, of Duke University in Durham, N.C., and colleagues analyzed functional MRI data from 15 young women (mean age 24.8 years) and 15 older women (mean age 70.2 years). The subjects viewed positive, negative and neutral images and later described the pictures as best as possible after a brief description.

Both age groups used the amygdala more for subsequent memory of negative pictures than neutral ones, the investigators found. Also, brain areas with more subsequent-memory activity for negative than neutral pictures showed a posterior-anterior shift in aging pattern. The results also showed functional connections between the amygdala and the bilateral dorsolateral prefrontal cortices, which is a region involved in emotional regulation, in older subjects, the researchers report.

"Compared with young adults, older adults had greater functional connectivity between the right amygdala and bilateral dorsolateral prefrontal cortices, a possible reflection of increased emotional regulation of negative pictures, but decreased functional connectivity between the amygdala and typical subsequent-memory regions such as the hippocampus, a possible reflection of decreased modulation by the amygdala and decreased memory retrieval for negative pictures. These findings advance understanding of the age-related alterations in the neural networks underlying subsequent memory for negative stimuli when affective function is preserved," the authors write.

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