Slow Oscillations Modulate Functional Brain Changes Supporting Working Memory

Abstract Working memory (WM), the temporary mental storage and manipulation of information, is a skill that can improve with training. Sleep, and specifically slow oscillations (SOs), has been linked with WM improvement, yet it is unknown how processing during SOs modulates WM function across sleep. The current study examines how WM-related neural processing changes with sleep, and how these changes are related to activity during SOs. To do so, participants performed a WM task during fMRI before and after sleep, and the first 2.5 hrs of sleep was monitored by simultaneous EEG-fMRI. Reliable overnight changes in WM-related activity patterns were found, with reduced recruitment of the dorsal precuneus after compared to before sleep. Moreover, greater neural activation during SOs was associated with reduced overnight recruitment during WM across multiple levels of analysis. Our findings highlight the important role of SOs, elucidating how SOs may support changes in WM function across sleep.