Decreased inhibitory control of negative information in directed forgetting.
Previous research has demonstrated that emotional material is more likely to be remembered than neutral material (Hamann, 2001). The present study employed the item-method of directed forgetting in order to examine whether emotionally negative words are not only easier to remember, but also harder to forget. Event-related potentials (ERPs) were additionally measured in order to investigate the processes of selective rehearsal and active inhibition in directed forgetting. The results demonstrated directed forgetting effects for both neutral and negative words, with a stronger effect for negative items. Late positive potentials (LPPs) for 'to-be-remembered' (TBR) relative to 'to-be-forgotten' (TBF) cues were enhanced when the cues followed negative in comparison to neutral words, indicating the greater selective rehearsal of TBR negative items. Frontal positivities to TBF relative to TBR cues were not modulated by word valence, indicating that inhibitory processes were unaffected by emotion. Taken together, the present research demonstrates for the first time that, not only are emotionally negative words prone to the same directed forgetting effects as neutral words, but that these effects are in fact enhanced for negative words and due to increased selective rehearsal of TBR negative items. The discrepancies between the present findings and those of previous studies are discussed.