Effects of Short Naps on EEG Microstates: Improving Sleep Deprivation-Induced Cognitive Impairment.

Purpose: Sleep can repair the brain damage caused by sleep deprivation (SD), however in many cases, it may not be feasible to get sufficient sleep. Napping is a simple strategy to mitigate the detrimental impacts of SD. However, the underlying mechanism behind how napping contributes to brain repair remains unclear. Electroencephalogram (EEG) microstate analysis is sensitive in detecting bottom-up and top-down attention control and rapid transitions between quasi-stable brain states due to its temporal resolution. This study aims to explore the effects of napping on cognitive impairments cause by SD and the potential mechanisms of cognitive recovery.

Patients and methods: We recruited forty-two healthy volunteers and recorded their EEG signals and psychomotor vigilance task (PVT) data at three time points: rested wakefulness, post-SD, and post-nap. EEG microstates analysis was used to explore changes of brain dynamic network. In addition, we investigate the alterations in microstate parameters and their correlation with behavior.

Results: We observed a significant decrease in participants' alertness levels following SD, which subsequently improved after napping. Four microstate classes (A, B, C, D) were identified by using EEG microstate analysis. The B-D transition increased significantly after SD and returned to baseline after napping, while A-D transition revealed opposite patterns. Notably, changes of time coverage and occurrence in microstate D were significantly correlated with changes of PVT performance after both SD and nap conditions.

Conclusion: Our results provide empirical evidence that short naps can effectively reverse negative effects of SD on vigilant attention, primarily through restoring the functionality of key brain networks involved in attention regulation.