Table 1.

Features of sleep macrostructure, EEG rhythmicity and functional EEG connectivity

Feature	Definition
Total sleep duration (min)	Time in bed spent in REM or NREM stage
Total stage duration (min)	Time in bed spent in each stage
Relative stage duration (%)	Percentage of sleep (from first non-W to last non-W) spent in each stage
Number of stage episodes	Number of stable (minimum 3 min) episodes in each stage
Mean stage duration (min)	Mean duration of episodes in each stage
Sleep latency (min)	Time in bed after lights are off to reach the first non-W stage
REM sleep latency (min)	Time in bed after first non-W stage to reach REM sleep
Sleep efficiency (%)	Percentage of time in bed after lights are off spent in a non-W stage
EEG slow wave power	Spectral EEG power in the frequency range 0.5–1.5 Hz
EEG delta power	Spectral EEG power in the frequency range 1.5–4 Hz
EEG theta power	Spectral EEG power in the frequency range 4–7.5 Hz
EEG alpha power	Spectral EEG power in the frequency range 7.5–11 Hz
EEG sigma power	Spectral EEG power in the frequency range 11–15 Hz
EEG beta power	Spectral EEG power in the frequency range 15–30 Hz
EEG slow wave coherence	Inter-hemispheric coherence in the frequency range 0.5–1.5 Hz
EEG delta coherence	Inter-hemispheric coherence in the frequency range 1.5–4 Hz
EEG theta coherence	Inter-hemispheric coherence in the frequency range 4–7.5 Hz
EEG alpha coherence	Inter-hemispheric coherence in the frequency range 7.5–11 Hz
EEG sigma coherence	Inter-hemispheric coherence in the frequency range 11–15 Hz
EEG beta coherence	Inter-hemispheric coherence in the frequency range 15–30 Hz

EEG, electroencephalogram; REM, rapid eye movement; NREM, non-rapid eye movement; W, wake.