Table 1.

Chronotype and sleep characteristics

	All Subjects (n=18)	ChronotypeMSFsc		ChronotypeDLMO
		Earlier (n=7)	Later (n=7)	Earlier (n=7)	Later (n=7)
DLMO	22.1 ± 0.3	22.1 ± 0.4	22.4 ± 0.4	21.2 ± 0.2	23.2 ± 0.2***
MSFsc	4.9 ± 0.2	4.2 ± 0.1	5.8 ± 0.2***	4.6 ± 0.3	5.1 ± 0.4
Bedtime	24.2 ± 0.2	23.9 ± 0.4	24.9 ± 0.3	23.5 ± 0.2	24.8 ± 0.3**

^***p<0.0001,

^**p<0.01,

^*p<0.05 between earlier and later chronotypes within chronotype group; data represent mean±SEM.