Figure 2.

Effects of i.v. orexin-A on DMS task performance in monkeys sleep deprived for 30–36 h. Performance was significantly impaired (SD, saline) compared with normal alert test sessions (Alert, saline). Intravenous orexin-A administered 10–15 min before testing in sleep-deprived animals partially reversed the detrimental effects on performance (SD + IV Orexin, 5.0 and 10.0 μg/kg). Trials were sorted according to cognitive load as in Figure 1. Horizontal line shows mean over all trials in normal alert saline sessions. *p < 0.01, **p < 0.001 indicate comparisons with similar trial types in non-sleep-deprived saline sessions; ^† p < 0.01, ^‡ p < 0.001 indicate comparisons between i.v. orexin-A at different doses and i.v. saline sleep-deprived sessions.