Sleep loss triggers wakeful brain cleaning that trades attention for maintenance

Short on sleep, the brain periodically triggers a sleep-like cleaning process during wakefulness, with cerebrospinal fluid moving out of the brain as attention lapses occur and then flowing back when focus returns. This compensatory mechanism temporarily reduces attention but may help restore cognitive function, suggesting a coordinated brain-body system—potentially involving the noradrenergic system—that links wakeful attention, fluid dynamics, and basic physiological signals.