Age differences in brain activity during emotion processing: reflections of age-related decline or increased emotion regulation?

Abstract

Despite the fact that physical health and cognitive abilities decline with aging, the ability to regulate emotion remains stable and in some aspects improves across the adult life span. Older adults also show a positivity effect in their attention and memory, with diminished processing of negative stimuli relative to positive stimuli compared with younger adults. The current paper reviews functional magnetic resonance imaging studies investigating age-related differences in emotional processing and discusses how this evidence relates to two opposing theoretical accounts of older adults' positivity effect. The aging-brain model [Cacioppo et al. in: Social Neuroscience: Toward Understanding the Underpinnings of the Social Mind. New York, Oxford University Press, 2011] proposes that older adults' positivity effect is a consequence of age-related decline in the amygdala, whereas the cognitive control hypothesis [Kryla-Lighthall and Mather in: Handbook of Theories of Aging, ed 2. New York, Springer, 2009; Mather and Carstensen: Trends Cogn Sci 2005;9:496-502; Mather and Knight: Psychol Aging 2005;20:554-570] argues that the positivity effect is a result of older adults' greater focus on regulating emotion. Based on evidence for structural and functional preservation of the amygdala in older adults and findings that older adults show greater prefrontal cortex activity than younger adults while engaging in emotion-processing tasks, we argue that the cognitive control hypothesis is a more likely explanation for older adults' positivity effect than the aging-brain model.

Fig. 1

Age differences in PFC involvement while processing negative stimuli. Negative stimuli induced greater PFC activity compared with neutral stimuli in older adults compared to younger adults (represented by black dots; online version: red dots). In some studies, where participants could anticipate negative stimuli, older adults showed less PFC activity than did younger adults (represented by white dots; online version: blue dots). See table 1 for a list of coordinates and studies used in the figure.

Fig. 2

Age differences in PFC involvement while processing positive stimuli. Although some studies showed greater PFC activity to positive stimuli than to neutral stimuli in younger adults than in older adults (shown by white dots; online version: blue dots), in studies with tasks requiring deep processing of stimuli, older adults recruited PFC more for positive stimuli than for negative stimuli (relative to younger adults), which is shown by black dots (online version: red dots). See table 2 for a list of coordinates and studies used in the figure.