Mood, memory, and visual event-related potentials in normal adults

The effect of mood-congruent learning on the P300 component of the event-related potential (ERP) was investigated. Music and stories with strong affective content were used to induce a positive or negative mood in 31 normal functioning adults. An incidental verbal learning paradigm using positive, negative, and neutral word stimuli was then presented while subjects' ERPs were recorded. P300 amplitude was examined in its relationship to performance on tests of recall and recognition memory for the stimulus words. It was hypothesized that there would be a mood-congruent learning effect, a P300 effect for memory, and an interaction between mood, memory, and the P300.;A mood-congruent learning effect was not found, and P300 amplitude did not differ for recalled vs. non-recalled words. However, when compared with low recall subjects, subjects who recalled a larger number of words had higher late P300 amplitudes. An ERP effect for word type was also found: negative words had a higher early P300 amplitude than did neutral or positive words at Fz and Cz, at Pz, positive words had the highest amplitude. No interaction was found between mood-induction, memory, and the P300.;The importance of looking at the nature of mood and stimuli processing requirements in trying to find the mood-congruent learning effect are discussed. As well, this study emphasizes the need of looking at factors operative at the time of encoding, such as semantic encoding, perceptual encoding, or processes related to mood, effort or arousal when looking at ERP and memory.