Figure 2

Distribution of actigraphic sleep acrophases. The percentiles with an actigraphic sleep acrophase at or below each time are plotted versus clock hours after midnight. The percentiles are plotted for 5 groups: a) absolutely certain DSPD 1, b) fairly certain DSPD 2, c) questionable DSPD 3, d) unlikely or very doubtful DSPD 4–5, and e) a representative population sample of San Diego adults.