Proceedings of the Annual Meeting of the Cognitive Science Society

Working memory (WM) provides the neurobiological infrastructure for human cognition. Dominant models positthat prefrontal cortex (PFC) supports WM by coordinating control over distributed memory representations. In two studies,multimodal electrophysiology data reveal that PFC control over WM is rhythmic, fundamentally dynamic, and not altogethernecessary. Direct brain recordings (n=10) demonstrate that PFC and medial temporal lobe (MTL) theta-band rhythms directa complex system of higher-frequency neural activity across regions, uncovering initial support for bidirectional PFC-MTLinteractions related to WM demands. Then, data from patients with unilateral PFC damage (n=14) challenge dominant modelson the central role of PFC (note 8% accuracy decrease in patients). In healthy controls (n=20), delta-theta-band rhythms precessfrom PFC toward parieto-occipital sites, concurrent with alpha-beta-band rhythms precessing in the opposite direction. All PFCeffects are diminished with unilateral damage, revealing an independent posterior WM mechanism. These results reveal thatrapid, parallel processing governs WM.