Temporal Dynamics of Multi-Item Working Memory Maintenance in Human Gaze Patterns and EEG

Maintaining multiple items in working memory (WM) requires the allocation of limited resources, which may involve prioritizing individual items over others. Previous work has suggested that attentional prioritization can vary rhythmically between WM samples, but direct empirical evidence for such temporal fluctuations remains scarce. Here, we recorded eye-tracking and EEG to track the temporal dynamics of multi-item processing while participants maintained up to three object orientations in WM. Whereas EEG encoding was only short-lived, miniature gaze patterns reflected the orientations of all three items throughout the entire WM delay and showed systematic load and serial position effects. Contrary to rhythmic sampling accounts, however, we found no evidence that eye movements alternated between the concurrently maintained items. Furthermore, the strength of WM encoding in gaze was not modulated by frontal theta activity in EEG, suggesting that oculomotor encoding was not directly coupled to rhythmic neural dynamics associated with WM and internal attention. Together, our findings indicate that the oculomotor signature of visuospatial WM processing was rather stably shaped by all of the simultaneously maintained items. The results further corroborate that eye-tracking and EEG provide complementary windows into the temporal dynamics of WM.