Figure 2

Mean sleep latency of MWT as a function of time of day. Mean ± standard deviation of the mean for sleep latency in minutes, for OD, 2NS, and 4NS groups for each time. Between groups comparisons: F (2, 56) = 11.03, p < 0.001. Within OD group: F_{(3, 66)} = 2.00, p = 0.126; within 2NS group: F_{(3, 57)} = 1.18, p = 0.326; within 4NS group: F_{(3, 45)} = 1.17, p = 0.331. MWT, Maintenance of Wakefulness Test; 2NS, two consecutive night shifts; 4NS, four consecutive night shifts; OD, off-duty.