Figure 4.

Rest-activity patterns of a newborn human (A) and a baboon (B) infant (right). Double-plotted actograms are shown. In A, dark bars represent sleep. In B, dark bars represent activity. Please note that the circadian phase of the baboons infant was shifted by exposure to a 200 lux reversed light-dark cycle at 30 days of age, and much less so by 50 lux of exposure at 55 days of age. Reproduced by permission from ref 16.