Figure 4
From: Optimized office lighting advances melatonin phase and peripheral heat loss prior bedtime
Melatonin secretion onset and offset times. Box plots for (a) melatonin secretion onset and (b) melatonin secretion offset, averaged across 2 days per condition, and aligned to elapsed time since habitual midsleep for both conditions (corresponding clock time is shown on the upper x-axis). Melatonin onset occurred significantly earlier in the Test room (red symbols; n = 31) than in the Reference room (blue symbols; n = 34; *: p = 0.048). There was no significant difference between both conditions for melatonin offset time. The box plots show mean (red and blue symbols inside the boxes), median (red and blue vertical lines), minimum and maximum values (red and blue horizontal bars).
