Planning the Potential Future during Multi-item Visual Working Memory

摘要

Working memory allows us to retain visual information toguide upcoming future behavior. In line with this future-orientedpurpose of working memory, recent studies have shown thataction planning occurs during encoding and retention of a singlevisual item, for which the upcoming action is certain. We askedwhether and how this extends to multi-item visual workingmemory, when visual representations serve the potential future.Human participants performed a visual working-memory taskwith a memory-load manipulation (one/two/four items) and adelayed orientation-reproduction report (of one item). Wemeasured EEG to track 15- to 25-Hz beta activity in electrodescontralateral to the required response hand—a canonical markerof action planning. We show an attenuation of beta activity, notonly in Load 1 (with one certain future action) but also in Load 2(with two potential future actions), compared with Load 4 (withlow prospective-action certainty). Moreover, in Load 2, potentialaction planning occurs regardless whether both visual itemsafford similar or dissimilar manual responses, and it predictsthe speed of ensuing memory-guided behavior. This shows thatpotential action planning occurs during multi-item visual workingmemory and brings the perspective that working memoryhelps us prepare for the potential future.