Abstract
Emotional expressions on face stimuli impact ERP components associated with visual perception and with goals for emotion processing. In younger adults, emotional expressions elicit larger peak voltage amplitudes for P1 and N170 over posterior electrodes and larger average voltages for EPN and LPC measured over posterior and centro-parietal electrodes, respectively. However, it is unclear if emotional expressions elicit similar enhancements for older adults. From a perceptual standpoint, emotion detection rules do not change with age. However, from a motivational standpoint, younger and older adults hold different goals for reacting to negativity. Consequently, patterns of brain activity may be age-dependent if divergent top-down goals moderate emotion perception. The current study investigated how neurocorrelates of emotion perception differ between older and younger adults at different times post-stimulus onset. Participants were presented with images of angry, happy, and neutral faces. ERPs were recorded using a 128-channel high-density electrode array and were time-locked to the visual onset of the faces. All participants displayed a larger amplitude N170 over occipito-temporal electrodes for emotional expressions relative to neutral; however, from 160-220 ms, older adults displayed a greater fronto-central positivity than did younger adults for emotional expressions. From 150-300 ms, both age groups continued to display greater emotion-related activation at posterior electrodes. From 220-300 ms, differential patterns of activity at parieto-central electrodes emerged. Relative to older adults, younger adults displayed a larger difference between angry and neutral expressions than between happy and neutral. This also was found from 300-800 ms over parieto-central electrodes. Overall, younger and older adults' visual systems display similar responses to emotional expressions, with emotional cues enhancing perceptual processing. However, from early on after stimulus onset until late in the epoch, there may be a dampening of older adults' reactivity to emotional expressions, especially negative ones.
Meeting abstract presented at VSS 2017