Fig. S4.

The effect of SW half-wave segment on the duration and slope measures of both positive and negative SW measures.

A. The effect of half-wave segment (initial versus final) and sleep-dependent regulation on the absolute slope and duration of SW for both negative and positive half-waves. Least square mean (Lsmeans) and standard error of the mean (SEM) are presented indicating sleep-dependent estimates at each 3-hour and 6.7-minute intervals (third of the sleep period) measured across all studied circadian phases and EEG derivations for both the initial and final segments (open circles = initial segment; filled bars = final segment). Data are double plotted for a better visualization of sleep-dependent rhythmicity. The level of significance is indicated for the main effect of sleep-dependent (H) regulation and the interaction (H ∗ S) with the segment of the SW half-wave factor (*P < .005, **P < .001, ***P < .0005).

B. The circadian regulation of SW half-wave duration and various types of slope measures (absolute values) as a function of half-wave polarity and half-wave segment. Lsmeans and SEM indicate circadian phase-dependent estimates at 60^o (~ 4 h) bins measured across all studied sleep intervals and EEG derivations for both the initial and final segments (open circles = initial segment; filled bars = final segment). Data are double plotted for a better visualization of circadian rhythmicity. Zero phase is set at the dim light melatonin onset. The level of significance is indicated for the main effect of circadian regulation (C) and the interaction (C ⁎ S) with the segment of the SW half-wave factor (***P < .0005).

C. The main effect of the segment of the half-wave, independent of the sleep-dependent and circadian factors on the slope measures (absolute values) and duration of both positive and negative SW half-waves (open bars = initial segment; filled bars = final segment) (*P < .005, ***P < .0005).