Sisi Wang^1,2, Freek van Ede²; ¹Texas Tech University, ²Vrije Universiteit Amsterdam

Working memory enables us to maintain visual information to guide upcoming behavior, bridging recent sensations to anticipated actions. While much prior work has focused on the storage mechanisms of visual working memory, recent studies highlight the dynamic processes through which stored contents are prepared for action. When visual items held in memory are associated with specific manual responses, visual and motor prioritization jointly emerge after retro-cues that indicate with certainty which memory item will be tested. However, real-world cues often vary in the degree of certainty they provide. It remains unclear whether visual prioritization and the prioritization of associated actions are similarly modulated by retro-cue reliability. To address this question, we used a visual–motor working memory task in which each of two memory items was linked to a different response hand. Critically, retro-cue reliability was manipulated across three levels (100%, 80%, 60%). Using EEG, we measured visual and motor prioritization during the delay period via posterior alpha (8–12 Hz) and central mu/beta (8–30 Hz) lateralization related to the cued memory item’s location (visual) or response hand (motor), respectively. Our results reveal dissociable effects of cue reliability on visual and motor prioritization in working memory. Visual prioritization was robust and remained stable across reliability levels. In contrast, motor prioritization profoundly scaled with cue reliability, showing weaker – and slower – motor prioritization following less reliable cues (lower certainty). Direct comparisons further showed distinct temporal profiles whereby visual and motor prioritization developed together following 100% reliable cues, while motor prioritization developed after visual prioritization with 80% reliable cues (and was absent with 60% reliable cues). These findings demonstrate a functional dissociation between visual and motor prioritization in working memory and provide new insight into how certainty shapes the dynamic processes by which working memory contents are prepared for behavior.

Acknowledgements: This work was supported by an NWO Vidi Grant (14721) and an ERC Starting Grant from the European Research Council (MEMTICIPATION, 850636) to F.v.E.