Figure 2.

PVT performance by group. Line graphs (A, C, E, and G) depict least-square means and standard error of the means (SEMs) of PVT performance as a function of time awake for men (gray circles), follicular (red), and luteal (blue) phase women. Dotted-line bars represent typical sleep periods (16–24 hr). Bar graphs (B, D, F, and H) adjacent to each line graph depict the least-square means and SEMs for the change (Δ) in each performance index from PVTs during typical wake to those during typical sleep, within-groups. *p < 0.05, **p < 0.01, ***p < 0.001 for independent sample t-tests.