PSG sleep monitoring was performed using a Grael 4 K system (Compumedics, Victoria, Australia). Including six‐channel of EEG (C3, C4, F3, F4, O1, O2, standard 10‐20 system, bilateral mastoid references), chin electromyography (EMG), and right and left outer canthi electrooculogram (EOG). The sampling rate was 512 Hz and the impedances were maintained below 10 kΩ. PSG indices included sleep onset latency (SOL), sleep efficiency (SE), and non‐rapid eye movement sleep stage 3 (NREM 3) duration.
