Table 1.

Sleep measures for the experimental night. Left column, sleep measure description. Middle column, average value of each sleep measure over all subjects. Right column, standard error of the mean for each sleep measure over all subjects.

Sleep Measures	Mean	s.e.m.
Sleep latency (min)	9.9	1.9
Wake after sleep onset (min)	15.9	2.6
Sleep efficiency (%)	93.8	0.6
Arousal Index (# per hr)	10.8	1.7
N1 sleep (min)	25.9	4.1
N2 sleep (min)	221.1	10.7
N3 sleep (min)	68.8	8.2
REM sleep (min)	80.3	5.5
Total sleep time (min)	396.1	6.4