Table 1.

Sleep architecture during the 3-h stimulation period and entire night in the older adults

	Stim	Sham	P-value
	Mean ± SEM	Mean ± SEM
TST (min)	449.32 ± 10.05	443.85 ± 13.56	0.588
Sleep onset (min)	10.91 ± 2.31	11.26 ± 2.13	0.867
Stimulation period
Wake (%)	9.75 ± 3.15	11.07 ± 3.15	0.552
S1 (%)	3.55 ± 0.59	3.84 ± 0.60	0.623
S2 (%)	56.95 ± 3.64	60.57 ± 3.27	0.242
SWS (%)	13.31 ± 2.91	11.85 ± 2.46	0.462
REM (%)	16.25 ± 1.86	12.48 ± 2.13	0.193
Arousal index (%)	7.01 ± 0.64	8.17 ± 1.18	0.388
Entire night
Wake (%)	12.07 ± 2.97	9.83 ± 1.70	0.423
S1 (%)	5.17 ± 0.54	5.67 ± 0.54	0.375
S2 (%)	56.08 ± 2.89	59.13 ± 2.10	0.266
SWS (%)	8.17 ± 1.64	7.38 ± 1.69	0.508
REM (%)	17.89 ± 1.52	17.68 ± 1.94	0.912
Arousal index (%)	6.64 ± 0.77	8.22 ± 0.91	0.216

Stimulation did not alter time spent in any of the sleep stages, total sleeping time, or number of arousals.

TST, total sleep time; S1–S2, sleep stages 1 and 2; SWS, slow wave sleep (i.e. S3 + S4); REM, rapid eye movement.