Group mean (±SEM) (A, B, E and F) and time course (mean ±SEM) (C, D, G and H) of EEG markers of arousal in the 8 hour (filled gray bars and ▼) and 5 hour (filled black bars and ▲) duration informed (DI) groups under actual 8-hour sleep opportunity (left panel) or in the 8-hour (unfilled gray bars and ᐁ) and 5-hour (unfilled black bars and Δ) DI groups under actual 5-hour sleep opportunity. Arousal measures included absolute power in the delta band (1.0–4.5 Hz) (A-D) and relative power density in the high-alpha band (10.5–11.5 Hz) (E-H). * Signifies main effect of group p<0.05; repeated measures REML linear regression [with either only group (A, B, E and F) or main and interaction effects of group x time (C, D, G and H)]. There was no significant effect of time or interaction on any of the measures.