Age and cortisol levels modulate judgment of positive and negative facial expressions.

There is some evidence that older adults respond to emotional stimuli differently to young adults, and that they may exhibit better performance on measures of memory and attention when stimuli are positive rather than negative in valence. A relation between cortisol levels and attention/memory for emotional stimuli in young adults has also been reported. The relationship between cortisol levels and the judgment of facial expressions of emotion in aging, however, has yet to be explored. The aim of this study was to investigate performance on a simple emotional face judgment task in young (N=37) and middle-aged (N=37) adults in association with salivary cortisol levels. Middle-aged participants were slower in responding to stimuli than younger participants. Cortisol levels were found to be associated with shorter response latencies to categorise emotional but not neutral faces, and with a greater tendency to judge neutral faces as being emotional. An interaction between age and cortisol levels emerged in response to angry faces; such that higher cortisol levels predicted significantly shorter reaction times to angry faces in young adults, but not in middle-aged adults. Thus, cortisol may be differently related to the processing of emotional facial expressions, particularly of anger, in middle-aged and young individuals. The findings are discussed in relation to the hypothesised changes in emotion regulation with aging.