Optimal Schedules of Light Exposure for Rapidly Correcting Circadian Misalignment
The top plot shows the entraining stimulus (LD-cycle) to the oscillator, plotted on a log scale, shifted by hours at time 0. The light level increases from 100 lux before time 0 to ( = 10,000 lux) after time 0. In this case ( = 7 hours) is positive, so the schedule is advanced. The middle plot shows the oscillations in first coordinate of the model. The entrained oscillator before the phase shift is shown with a solid line, and the dotted line shows how the oscillator would behave were it entrained to the shifted stimulus. The solid line after time 0 shows the process of re-entrainment to the phase shift. The last plot shows the phase of the stimulus or, equivalently, of the entrained oscillator. Notice that the shift takes place when the phase of the stimulus (and therefore of the entrained oscillator) is ( = 7 hours). All significant features are labeled with the appropriate notation (See Methods, or Setting up the Problem in supplemental text S1).