Memory Reactivation Levels Remain Unaffected by 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 (in Experiment 1) and anticipated interference task (in Experiment 2) on reactivation of LTMs in WM using contralateral delay activity (CDA) in the EEG. On each trial, participants saw one or three previously studied or novel objects that were tested after a brief retention interval. In half of the blocks, the retention contained perceptual distractors (Experiment 1) or an interference task (Experiment 2). The CDA prior to the interference period was lower for studied than for novel items and was unaffected by anticipated interference, with no interaction between interference expectation and memory type. Additionally, we measured contralateral alpha power suppression as an index of spatial attention. We found that spatial attention allocated to the memorized objects' locations also was not modulated with anticipated interference. These findings indicate that anticipating interference does not influence the extent to which WM is engaged in representing information stored in LTM.