Subjects arrived at the laboratory in the afternoon and were provided 9h time-in-bed (TIB) for their baseline sleep night. The first functional magnetic resonance imaging (fMRI) scan session took place the next morning (Baseline [BL] day) from 0700h-1000h. Subjects were then randomized to either a total sleep deprivation (TSD) or control condition. During the second night of the study, sleep-deprived subjects were kept awake and control subjects were allowed 8 h TIB to sleep. The second fMRI scan session took place the next morning from 0700h-1000h (total sleep deprivation [TSD] day or control day 1 [CD1]). Sleep-deprived subjects were then allowed 12 TIB for recovery sleep and control subjects were allowed 8 h TIB to sleep. Each subject was scanned at the same time for each scan to avoid potential time-of-day differences between scans. Subjects had ad libitum to food/drink during the study. Subjects remained in the laboratory for the duration of the study and were monitored by trained staff at all times to ensure adherence to the protocol.