Recognition of emotional pictures: Behavioural and electrophysiological measures

The effects of emotional content of images on recognition memory were studied, bringing together electrophysiological (Event-Related brain Potentials, ERPs) and behavioural (accuracy and speed of recognition, and remember/know judgements) indices. In the study phase, participants assessed 120 images on the scales of valence and arousal. In the test phase, ERPs were recorded while participants viewed again the images, put together with 120 new, and were asked to make old/new decisions and remember/know judgements on them. A clear arousal bias was obtained for remember/know judgements, which revealed that correctly recognised arousing images (negative and positive) received more remember judgements than nonarousing images (neutral and relaxing). Moreover, a Late Positive Component (LPC) activation revealed an old/new effect enhanced by arousing images. The LPC activation was located in parietal areas (precuneus), which appears to be mostly related to successful retrieval based on recollection. The results obtained through different indices supported the emotional bias found in previous studies for arousing material, but do not clarify the effect of the emotional valence on recognition.