Restorative Effects of Daytime Naps on Inhibitory Control: A Neuroimaging Study Following Sleep Deprivation

Sleep deprivation is known to impair cognitive performance, particularly inhibitory control, which is crucial for goal-directed behavior. While extended recovery sleep is the ideal solution, the fast-paced demands of modern life often make this impractical. Brief daytime naps have emerged as a potential countermeasure, but the neural mechanisms underlying their restorative effects remain underexplored.

This study aimed to investigate the effects of a 30-minute daytime nap on brain activation patterns and cognitive performance following sleep deprivation. We used task-based functional magnetic resonance imaging (fMRI) to examine how naps modulate brain regions involved in inhibitory control.

Forty-five participants completed a dual-choice Oddball task under three conditions: Resting Wakefulness (RW), Sleep Deprivation (SD), and Post-Nap (Nap). Reaction times (RT), accuracy, and brain activation patterns were measured and analyzed across these states. Task-related brain activation was examined using fMRI, focusing on regions involved in the frontoparietal and default mode networks (DMN).

Sleep deprivation significantly impaired inhibitory control, as reflected by slower RTs and reduced accuracy. A 30-minute nap partially restored cognitive performance, with RTs and accuracy showing intermediate improvement between RW and SD. Neuroimaging data revealed that the nap restored positive activation in the prefrontal cortex, occipital lobes, and middle frontal regions, which had been significantly reduced during SD. Furthermore, the nap enhanced negative activation in the middle temporal gyrus and cingulate gyrus, regions associated with the DMN, reducing cognitive interference from irrelevant stimuli.

Daytime naps significantly mitigate the cognitive deficits induced by SD through two primary mechanisms: (1) enhancing positive activation in task-relevant brain regions and (2) increasing negative activation in areas involved in the DMN. These findings provide novel insights into the neural basis of nap-induced cognitive recovery, underscoring the value of naps as an effective intervention to restore inhibitory control following SD.