Individual differences in working memory reactivation of long-term memories predict protection against anticipated interference

Most daily tasks require frequent information exchange between working memory (WM) and long-term memory (LTM). However, the factors that modulate the reactivation of LTMs in WM remain to be explored. Here, we tested the effects of anticipated perceptual interference on reactivation using contralateral delay activity (CDA) in the EEG. On each trial, participants saw a previously studied object that was tested after a brief retention interval. In half of the blocks, the retention contained perceptual distractors. Half of the participants had larger CDA on interference blocks (WM preparers) and others on no interference blocks (LTM preparers). WM preparers showed smaller interference costs in accuracy suggesting that preparing against interference via reactivating LTMs in WM is a more effective strategy than relying on passive LTMs. Moreover, in interference blocks, contralateral alpha suppression, an index of spatial attention, disappeared during retention in anticipation of interference, mostly in WM preparers. These results indicate that individuals stopped attending to reactivated memories when anticipating interference, presumably to prevent the involuntary encoding of perceptual distractors that appear at attended locations. Together, these results highlight individual differences in preparing for anticipated interference in recruiting WM to store LTMs, and their effects on proneness to interference.