Age differences in the emotional modulation of ERP old/new effects

The emotional salience of stimuli influences ERP old/new effects, but despite proven age differences in emotional processing, the influence of emotion on old/new effects has previously been investigated in younger adults only. Therefore, we set out to examine age differences in the emotional modulation of old/new effects. To this end, the electroencephalogram of younger (17-27 years) and older (63-77 years) adults was recorded while they completed a continuous recognition test with unpleasant, neutral and pleasant pictures. Because recollection is typically enhanced by emotion, the parietal old/new effect was expected to be larger for emotional than neutral stimuli in the younger adults. Because recollection suffers from age-related decline, emotion enhancement of the parietal old/new effect was not expected in the older adults. The results showed that, in both age groups, recognition accuracy was not affected by emotion and that the response bias was more liberal for unpleasant pictures. The younger adults displayed an early, a parietal and a late frontal old/new effect, whereas the older adults showed an early, no parietal and an inverse left-lateralized late frontal old/new effect. Further, the emotional modulation of the old/new effects differed with age. Importantly, emotion enhanced the parietal and late frontal old/new effects in younger adults, and the early old/new effect in older adults. This suggests that whereas recollection and post-retrieval processes are augmented in emotional recognition memory in younger adults, familiarity is enhanced by emotional salience in older adults.