Effect of emotional valence on episodic memory stages as indexed by event-related potentials

Abstract

Several investigations have shown that emotional events show superior recall than non-emotional ones. However, the cortical mechanisms underlying the episodic recall of emotional scenes are still poorly understood. Our main aim was to compare the mag-nitude of the Event-Related brain Potentials (ERP) old-new effect related to emotionally unpleasant, pleasant and neutral photographic images. As ex-pected, correct recognition of all types of images elic-ited three topographically distinct ERP components sensitive to the classical old-new recognition effect. The results revealed that the behavioral perform-ances were mainly sensitive to arousal, while the ERP old/new effect over posterior regions (300 -1000 ms) was exclusively affected by unpleasantness. A later component (1000 -1400 ms) showed an inverted old/ new effect at parietal sites, which was also sensitive to unpleasantness. These results imply that ERP re-flecting episodic conscious recollection and post-re-trieval monitoring are clearly affected both by va-lence and arousal.