FRONTOPARIETAL OSCILLATORY DYNAMICS SUPPORTING VISUOSPATIAL WORKING MEMORY OPERATIONS

Visuospatial working memory (WM) is a core capacity for goal-directed cognition and is compromised across many neurological disorders, yet the oscillatory mechanisms that differentiate visuospatial retention from manipulation remain poorly specified. Using a novel visuospatial WM task, we combined EEG with individual MRI-informed source reconstruction to identify anatomically and frequency-specific dynamics that predict behavior and can guide neuromodulation. Thirty healthy adults completed retention and manipulation trials during EEG. Time-frequency and source-level analyses quantified delta, theta, alpha, beta, and gamma activity within the frontoparietal network and related these measures to accuracy and response time. Both conditions expressed a shared encoding profile at stimulus onset: beta and gamma increases, theta synchronization, and alpha desynchronization, followed by an alpha rebound after stimulus offset. Critically, manipulation reinstated similar patterns during retrieval and online updating, consistent with recurrent reactivation during transformation. Better retention was linked to parieto-occipital theta synchronization and frontal and parieto-occipital alpha desynchronization. Better manipulation was selectively associated with parieto-occipital alpha desynchronization together with frontal delta and theta synchronization, implicating increased attentional demands and executive control. These source-resolved oscillatory signatures establish actionable, frequency- and region-specific neural targets that could be leveraged by neuromodulation approaches, such as rTMS, to move from correlational descriptions toward mechanism-based intervention in visuospatial WM.