Planning the Potential Future during Multi-item Visual Working Memory.

Working memory allows us to retain visual information to guide upcoming future behavior. In line with this future-oriented purpose of working memory, recent studies have shown that action planning occurs during encoding and retention of a single visual item, for which the upcoming action is certain. We asked whether and how this extends to multi-item visual working memory, when visual representations serve the potential future. Human participants performed a visual working-memory task with a memory-load manipulation (one/two/four items) and a delayed orientation-reproduction report (of one item). We measured EEG to track 15- to 25-Hz beta activity in electrodes contralateral to the required response hand-a canonical marker of action planning. We show an attenuation of beta activity, not only in Load 1 (with one certain future action) but also in Load 2 (with two potential future actions), compared with Load 4 (with low prospective-action certainty). Moreover, in Load 2, potential action planning occurs regardless whether both visual items afford similar or dissimilar manual responses, and it predicts the speed of ensuing memory-guided behavior. This shows that potential action planning occurs during multi-item visual working memory and brings the perspective that working memory helps us prepare for the potential future.