Early reactivation of emotional valence in ERPs to neutral retrieval cues
Holly J. Bowen1, Eric C. Fields2,3, Elizabeth A. Kensinger2; 1Southern Methodist University, 2Boston College, 3Brandeis University
Much of the research examining why memories of negative and positive events have distinctive behavioral and neural profiles have focused on differences at encoding, with less emphasis on processes that occur at retrieval. Some studies have shown differences in memory and ERP waveforms during retrieval of neutral stimuli previously encoded in a negative compared to neutral context, but few studies have included positive stimuli to examine valence effects directly. In the current study we used ERPs to examine the time course and electrophysiological correlates of valence differences in memory retrieval. At encoding, participants (n = 25) viewed negative, positive and neutral images paired with neutral words. At retrieval, the neutral words were presented alone and participants were asked to make a remember/know judgment while EEG was recorded. The hit rate for items previously encoded with negative images, positive images, and neutral images, did not statistically differ. Valence effects in the ERP data began to emerge around 200 ms after the onset of the retrieval cue in the form of a parietally distributed positivity. Words encoded with positive and negative images elicited a larger positivity than words encoded with neutral images, with no significant difference between positive and negative. This effect occurred before the commonly observed frontal old-new effect (~400 ms) and before the earliest old-new effect observed in the present data, indicating that reactivation of the prior emotional context occurs in the very early phases of memory retrieval and before stimulus recollection.
Topic Area: EMOTION & SOCIAL: Emotion-cognition interactions