Abstract
BACKGROUND: Sleep deprivation (SD) impairs working memory (WM), yet the restorative potential of brief daytime naps remains underexplored. This study examines how naps counteract SD-induced WM deficits through behavioral and neuroimaging mechanisms, focusing on task-positive networks and default mode network (DMN) dynamics. METHOD: A within-subject fMRI study employed 2-back WM tasks in 50 participants under three conditions: baseline wakefulness, post-30h SD, and post-nap recovery. Behavioral metrics (reaction times, accuracy) and fMRI activation patterns were analyzed using repeated-measures ANOVA and mixed-effects models to assess SD and nap effects. RESULT: Naps partially restored SD-induced WM declines, improving reaction times and accuracy. Post-SD, reduced activation in the cerebellum, insula, and thalamus (attention/executive regions) rebounded post-nap. SD weakened DMN suppression (middle frontal gyrus, precuneus, superior temporal gyrus), with maximal DMN suppression post-nap. Improved WM performance correlated with reactivated task-positive networks. CONCLUSION: Daytime naps mitigate SD-related WM deficits by rebalancing task-positive network activation (cerebellum, thalamus) and enhancing DMN suppression. These findings elucidate neurophysiological mechanisms of sleep-cognition interactions, supporting naps as a practical intervention for SD-induced cognitive impairment.