Enhanced selective memory consolidation following post-learning pleasant and aversive arousal

It is well established that emotions modulate memory, typically enhancing consolidation through post-learning arousal. However, many aspects of this phenomenon have yet to be delineated. For example, it remains unclear whether or not the type of arousal is relevant (pleasant vs. aversive), whether arousal enhances memory selectively for some stimuli but not others (emotional vs. neutral), which specific aspects of the stimulus representation (gist vs. detail) are affected, and whether these mechanisms are sexually dimorphic. In order to explore these issues, 178 undergraduate participants viewed a series of negative, positive and neutral pictures. They were then subjected to a post-learning arousal manipulation in the form of a pleasantly arousing-, aversively arousing-, or neutral video. Free recall tests one week later indicated that both pleasant and aversive post-learning arousal enhanced memory consolidation for positive and negative but not neutral stimuli, independent of the participants' sex. Further analysis for gist and detail aspects suggests that post-learning arousal enhances memory for the gist of the stimuli. The study has implications for the understanding of healthy and pathological cognitive-affective processes in humans. (C) 2007 Elsevier Inc. All rights reserved.