Table 1.

Effect of EEG slow wave suppression on sleep parameters

	EX		RC
	Control	SWA(−)	Control	SWA(−)
Total sleep time	228.9 ± 3.6	217.6 ± 3.4	440.4 ± 8.7	457.5 ± 3.5
Sleep efficiency (%)	95.3 ± 1.5	90.7 ± 1.4	91.8 ± 1.8	95.3 ± 0.7
Waking after sleep onset	2.3 ± 1.6	10.9 ± 2.9*	18.6 ± 9.6	4.8 ± 1.6
Movement time	3.5 ± 1.5	5.1 ± 1.2	9.2 ± 3.4	9.2 ± 2.0
Stage 1	10.9 ± 2.0	15.2 ± 1.3	20.1 ± 2.4	16.7 ± 2.6
Stage 2	92.0 ± 5.2	131.1 ± 7.5**	227.6 ± 14.7	226.7 ± 10.5
Slow-wave sleep	73.6 ± 10.7	26.3 ± 7.2***	87.5 ± 16.5	126.4 ± 15.0
REM sleep	52.4 ± 4.8	45.0 ± 4.4	105.3 ± 9.7	87.8 ± 7.3

Data are in minutes and are shown for 4 h EX sleep episode and 8 h RC sleep episode. SWA(−) refers to the group in which EEG slow waves were suppressed with sounds during EX sleep. Control refers to the group in which no sounds were presented. Slow-wave sleep corresponds to the sum of stage 3 and stage 4. Data represent means ± SEM [n = 9 for SWA(−), n = 6 for control]. Differences between groups were analyzed with one-factor ANCOVAs with corresponding sleep parameter during the preceding 8 h baseline episode (data not shown) as covariate (see Materials and Methods, Statistical analysis). Separate ANCOVAs were performed for EX and RC sleep. Significant differences are indicated by asterisks.

*p = 0.0497; **p = 0.0019; ***p = 0.0012.