Figure 7

EEG data analysis pipeline. (A) Whole-night polysomnography recordings were staged into wake, REM and NREM-1, -2 and -3 sleep stages. (B) EEG traces from 6 channel locations were segmented into 5-s epochs. Epochs containing artefact were removed. (C) Each 5-s epoch was subjected to fast Fourier transform to obtain power spectra for each EEG channel. (D) Power spectra were averaged across sleep stages and integrated across standard frequency bands (coloured bars). Subsequently, the absolute power at each frequency band was averaged across all channels to obtain global EEG power, and across left and right channels to obtain intra-hemispheric EEG power. s seconds, Ch channel.