Table 1.

Effects of the interventions on the Stanford Sleepiness Scale score. Data are presented as mean ± S.D.

Intervention	Day	Stanford Sleepiness Scale (n=6)	Mean Stanford Sleepiness Scale	P vs No light
No light	1	3.0 ± 1.0	3.9 ± 1.4	−
	2	3.7 ± 1.4
	3	4.5 ± 1.4
	4	4.3 ± 1.5
50%-cut	5	3.2 ± 1.0	3.3 ± 1.5	0.148
	6	3.3 ± 2.0
	7	3.2 ± 1.6
	8	2.5 ± 0.8
30%-cut	9	2.2 ± 0.8	2.6 ± 1.1	0.002
	10	2.8 ± 1.5
	11	2.5 ± 0.8
	12	2.8 ± 1.2