Novel fearful faces activate the amygdala in healthy young and elderly adults

Abstract

Activation of the amygdala to emotionally valenced stimuli, and particularly to fearful faces, has been widely demonstrated in healthy young adults. However, recent studies assessing amygdala responses to fearful emotional faces in the normal elderly have not shown similar results. The reason for this is uncertain, but it may relate to life-span developmental changes in processing emotional stimuli or structural alterations in the amygdala with aging. In order to examine whether the amygdala could be activated in the elderly, we developed a paradigm designed to engage the amygdala on several levels. Based on recent imaging work indicating that novelty and stimulus change activates the amygdala, we assessed amygdala responses in young and elderly adults to novel fearful faces (versus familiar neutral ones). We demonstrate a robust activation in both groups, indicating that the amygdala remains responsive in aging. This activation did not differ between the two groups when we examined regions of interest in the amygdala based on functional or structural criteria. However, there were significantly greater activations in the inferior temporal cortex in the young versus elderly subjects.