Overview
- Researchers tested 26 adults twice, after a full night’s rest and after total sleep deprivation, using simultaneous EEG, pupillometry and modified fMRI that tracked cerebrospinal fluid flow during visual and auditory attention tasks.
- During brief lapses, cerebrospinal fluid was expelled from the brain and then drawn back in as focus returned, with loss of attention occurring about 2 seconds before outflow and re-entry about 1 second after recovery.
- The lapses carried a body-wide signature, including pupil constriction roughly 12 seconds before fluid outflow and concurrent drops in breathing and heart rate, followed by pupil dilation after the lapse.
- The authors hypothesize that sleep-deprived brains initiate sleep-like cleansing pulses while awake at the cost of momentary attention, and they propose a unified control circuit with the noradrenergic system as a candidate.
- Experts caution that the findings are correlational in a small, mostly young sample and that it remains unclear whether these events are protective maintenance or potentially harmful, warranting further study.