Figure 1
From: Circadian dynamics in measures of cortical excitation and inhibition balance
Experimental protocol.
Twenty-two healthy young men (22.8 ± 2.6 y.o.) underwent 8 TMS/EEG sessions during 29-h sleep deprivation to cover the ~24 h circadian cycle under constant routine conditions. EEG recordings of TMS evoked responses were distributed with a higher frequency around the so-called evening “wake maintenance zone”, which occurs before melatonin onset and corresponds to the periods when the circadian system maximally favors wakefulness. Higher frequency also occurred in the morning “sleep promoting zone”, when the circadian system maximally promotes sleep, before it favors wakefulness again. During TMS/EEG sessions, participants performed a visuo-motor vigilance task. TMS/EEG sessions were immediately preceded by 2-min recordings of spontaneous quiet waking EEG.
