Figure 1
The actograms show representative daily activity-rest patterns of full-term infants of approximately 1.5 years of age with advanced nap phases (a) and delayed nap phases (b). The vertical axis shows the 7 consecutive observation days and the horizontal axis shows the course of each 24 h day from 00:00 h (12:00 am) to 24:00 h (12:00 am). Activity counts per minute are represented by the height of the vertical black bars on each actogram. The arrows and the blue rectangles indicate naps and bathing periods, respectively. The red underlines are the periods that were automatically judged as sleep periods by the actigraph software.
