Implicit effects of emotional contexts: an ERP study.

Previous recognition memory experiments have demonstrated that the ERPs elicited by correctly recognized test items differ according to whether the items were encoded in an emotionally arousing or an emotionally neutral context. It is not clear, however, whether these ERP differences depend on the explicit recognition of the items. We addressed this question in the present study by contrasting the ERPs elicited by test items encoded in emotionally negative or emotionally neutral study contexts, according to whether the items were correctly recognized or misclassified as new. Recognized items associated with emotional rather than neutral contexts elicited an early positive-going and a later negative-going effect that resembled the effects reported in prior studies. Relative to unrecognized items encoded in neutral contexts, unrecognized items encoded in emotional contexts elicited a sustained, frontal-maximum, positive-going effect that onset at about 200 ms poststimulus. This effect may reflect an influence of emotional arousal on the neural correlates of implicit memory.