Figure 2.

Main effects of circadian phase (left) and time awake (right) on performance across the 6-week forced desynchrony segment. Data in the left (circadian phase) panels are double-plotted with respect to the circadian phase of the core body temperature rhythm (with the fitted temperature nadir (Tmin) = 0°). Data in the right (time awake) panel are plotted with respect to the time since scheduled wake time. Panel A: Performance on an addition calculation test (ADD), showing number of correct calculations per 4-minute test. Panel B: Psychomotor Vigilance Task (PVT) mean reaction time (RT), in milliseconds (msec). Panel C: PVT fastest 10% RT. Panel D: Number of PVT lapses (RT > 500 milliseconds). Note that the y axes for Panels B-D are inverted to better visualize how performance on all 4 measures change in parallel.