Pre-bedtime alertness was assessed using subjective sleepiness (A), reaction time on a 10-min psychomotor vigilance task (B), and EEG spectral profiles from Fz- (C), Cz- (D), Pz- (E) and Oz- (F) derivations. Sleep related outcome measures were assessed based on the lighting condition (C-LED vs. FL; G, H, I, J) and based on the order of presentation of the lighting condition (C-LED/FL vs. FL/C-LED; K, L, M, N). Sleep related outcome measures included total sleep time (G, K), % sleep efficiency [(TST/TIB)*100] (H, L), and slow wave activity during the first 90-min of non-rapid eye movement sleep calculated from the C3- (I, M) and C4- (J, N) derivations. Data are expressed as group means ± SEM. * and ● p<0.05 between lighting conditions.