Mechanisms of Working Memory Prioritization: Retro-cues vs. Saccadic preparation

Selective internal attention allows working memory (WM) contents to be prioritized according to task demands, a process typically investigated with the retro-cue paradigm. In this paradigm, a cue presented during WM maintenance indicates which item will be tested, enabling voluntary allocation of attentional resources and typically enhancing memory performance. Recent findings suggest, however, that saccade preparation toward the location of a WM item can also produce an involuntary prioritization effect. In the present study, we compared behavioral performance and neural oscillatory dynamics associated with involuntary prioritization induced by saccade preparation and voluntary prioritization elicited by spatial and color retro-cues. Behaviorally, saccade-based prioritization produced only a modest benefit relative to incongruent items, whereas both types of retro-cues yielded substantially larger improvements. At the neural level, alpha-band lateralization showed a similar spatial-attention pattern across all prioritization conditions, supporting a shared covert attentional mechanism. In contrast, bilateral posterior alpha power was reduced following retro-cues compared to saccadic preparation, consistent with a release of WM load when non-cued items are deprioritized. Overall, our results indicate that voluntary and involuntary mechanisms of WM prioritization rely on overlapping spatial-attention processes, but differ in strategic control and their consequences for load management. Importantly, top-down prioritization through retro-cues produces a stronger behavioral enhancement than involuntary prioritization driven by saccade preparation.