Differences in resting-state theta power predicts vulnerability in alertness during prolonged wakefulness

Prolonged wakefulness-such as staying up for work or study-is a common form of sleep loss in modern society. Previous research using sleep-deprivation paradigms has indicated inter-individual differences in vulnerability to sleep loss, but the neural correlates of such vulnerability during prolonged wakefulness remain unclear. In a laboratory-controlled setting, we examined individual differences in alertness alteration during overnight wakefulness-a more common form of sleep loss in real life-and explored the associated resting-state EEG spectral signatures. Forty-five participants remained awake from 22:00 to 06:00, during which they completed subjective ratings, a 10-min psychomotor vigilance task (PVT), and resting-state EEG recordings every 2 h. Based on the changes in overnight PVT performance, participants were grouped as vulnerable (N = 20) or resilient (N = 20). Vulnerable individuals exhibited larger variations in frontal theta power, whereas resilient individuals demonstrated relatively stable resting-state EEG activities during prolonged wakefulness. Furthermore, higher theta power in the parietal region was observed in vulnerable people before prolonged wakefulness, which might be a predictor of vulnerability to prolonged wakefulness. Future studies with larger and independent datasets are needed to validate these spectral indicators and clarify underlying mechanisms.