When can we choose to forget? An ERP study into item-method directed forgetting of emotional words.

Emotionally arousing information is treated in a specialised manner across a number of different processing stages, and memory for affective events is often found to be heightened by virtue of this. However, in some cases, emotional experiences might be the very ones that we would like to forget. Here, two item-method directed forgetting studies are presented which investigate people's ability to intentionally forget affective words when stimuli and memory instructions are presented simultaneously. In the first experiment an interaction between task instruction and emotional content was evident in a diminished directed forgetting effect for emotional words, suggesting that they may be relatively resistant to deliberate forgetting. The interaction between instruction and emotion appeared both in free recall of words and in a yes-no recognition task. In the second study, an ERP procedure was utilised to investigate whether emotion modulates the effects of instruction during the initial encoding of stimuli. Recognition data again showed a clear interaction between instruction and emotion, with a reduced directed forgetting effect for emotional words. The ERP data demonstrated evidence for individual effects of both emotion and instruction during encoding; however, despite this, no evidence for an interaction between these factors was evident in the ERP data. As such, we conclude that even when study items are presented simultaneously with their associated memory instructions, neither does emotion prevent differential processing of directed forgetting instruction, nor does memory instruction prevent differential processing of emotion during early encoding. Implications are discussed in relation to the directed forgetting literature and more broadly with respect to circumstances under which emotion and cognitive processing work in parallel or in competition with each other.