Figure 6.

A comparison between time of peaks in total daily sleep hours (top panel) and bouts (lower panel) as derived from the CLUSTER peak analysis, and body length growth spurts as previously identified (17) (middle panel) during 93 days from 117 days of age in a male infant. He experienced 10 significant peaks in total daily sleeping hours, 4 sleep bouts and grew 6.8 cm in 9 growth spurts. Seven length growth saltations were non-randomly linked to sleep hour peaks (P = 4.96 × 10^-7) and 2 to sleep bout peaks (P = 0.045). The first growth saltation also seems to occur at the time of increased sleep, but the time frame was too short to permit identification of an upstroke, if present, and this apparent sleepy day is not identified as a peak by algorithm definition.