Figure 3. Average waveforms of circadian variables after moderate and bright light treatment.

Time course of core body temperature, plasma melatonin, cortisol and subjective alertness during the constant routine in moderate light and bright light treated participants. Subjective alertness data were averaged per 2-h bins. All date are referenced to the projected wake time (22:00 clock-time). Box indicates the timing of the sleep episode on the previous day. Data represent means+/− SEMs.