An electrophysiological comparison of recollection for emotional words using an exclusion recognition paradigm

The positive-going shift of event-related potential (ERP) components that occur when recognizing emotional words has been thought to be due to valence effects on either recollection or familiarity. This study investigated the independent contributions of recollection and familiarity on recognition of emotional words in order to examine which is thus responsible for the greater magnitude of ERP components seen in response to recognition of emotional, as opposed to neutral words. ERPs were measured while participants completed an exclusion recognition task. In the test phase, participants were required to respond "old" only to target items, which were included in one of two lists that were presented in the study phase. They were also asked to respond "new" to distracters and non-target items that were in the other previously presented list. "Old" responses to targets and non-targets were contrasted with an ERP analysis. Results suggested that the late positivity reflected recollection. The magnitude of this positivity, elicited around the left parietal area, was greater for negative stimuli compared to neutral and positive stimuli. The findings of the present study suggested that enhanced recollection of negative words may contribute to increased magnitudes of components such as the LPC. The emotional valence of words may have separate behavioral and electrophysiological effects on recollection and familiarity.