Visual working memory guides attention rhythmically in humans.

Abstract

How does internal representation held in visual working memory (VWM), known as the attentional template, guide attention in humans? A longstanding debate concerns whether only one (Single-Item-Template theory) or multiple (Multiple-Item-Template theory) items serve as attentional templates simultaneously. Here, we propose a Rhythmic-Item-Template hypothesis, successfully reconciling these seemingly contradictory theories. Using the classical VWM-guided attention task with human participants, we found that two VWM items alternately dominate behavioral guidance in theta-rhythmic (4-8 Hz), with anti-correlated activation states in time, and more importantly, this rhythmic oscillation was not driven by the retro-cue processing. Neural recordings revealed that occipital alpha oscillation (8-14 Hz) governed item-specific prioritization, and its amplitude closely tracked subjects' behavioral guidance, while frontal theta-oscillations phase-led and coupled with occipital alpha oscillations during the item transition. Our Rhythmic-Item-Template results not only resolve previous Single-Item-Template versus Multiple-Item-Template debate but also advance our understanding of how distributed brain rhythms coordinate flexible resource allocation in multi-item memory systems.