Binocular rivalry: a window into emotional processing in aging.

Previous binocular rivalry studies with younger adults have shown that emotional stimuli dominate perception over neutral stimuli. Here we investigated the effects of age on patterns of emotional dominance during binocular rivalry. Participants performed a face/house rivalry task where the emotion of the face (happy, angry, neutral) and orientation (upright, inverted) of the face and house stimuli were varied systematically. Age differences were found with younger adults showing a general emotionality effect (happy and angry faces were more dominant than neutral faces) and older adults showing inhibition of anger (neutral faces were more dominant than angry faces) and positivity effects (happy faces were more dominant than both angry and neutral faces). Age differences in dominance patterns were reflected by slower rivalry rates for both happy and angry compared to neutral face/house pairs in younger adults, and slower rivalry rates for happy compared to both angry and neutral face/house pairs in older adults. Importantly, these patterns of emotional dominance and slower rivalry rates for emotional-face/house pairs disappeared when the stimuli were inverted. This suggests that emotional valence, and not low-level image features, were responsible for the emotional bias in both age groups. Given that binocular rivalry has a limited role for voluntary control, the findings imply that anger suppression and positivity effects in older adults may extend to more automatic tasks.