We studied how natural loss of consciousness during sleep affects visual processing using high density scalp EEG in healthy human participants. We found attenuated fast frequency following responses in the visual cortex in sleep (N/REM) compared to wakefulness while slow and onset responses were stronger in sleep. These results supports the view that during sleep the cortex ability to process basic information is very much limited but factors shared in NREM and REM sleep, for example low noradrenergic tone.
Attenuated Fast Steady-State Visual Evoked Potentials During Human Sleep
