Table 1.

Mean (and standard error; SEM) sleep parameters recorded during the 90‐minute daytime nap retention interval in both young and older participants

	Young		Older		t	P
	M	SEM	M	SEM
Wake (min)	19.85	3.44	47.09	7.47	−3.31	0.004a
Stage 1 (min)	7.87	1.36	6.18	0.76	1.28	0.270
Stage 2 (min)	43.31	2.28	31.02	5.22	2.16	0.044a
SWS (min)	11.45	2.41	4.60	1.75	2.35	0.027a
Non‐REM (min)	54.77	3.13	35.62	6.20	2.76	0.012a
REM (min)	9.44	2.10	4.20	2.18	1.72	0.098
Total sleep time (min)	72.08	3.56	46.00	7.26	3.23	0.004a
Stage 1% TST	11.51	2.36	20.14	4.15	−1.08	0.084
Stage 2% TST	60.98	2.86	67.40	3.33	−1.44	0.162
SWS% TST	15.41	3.10	7.01	2.61	2.09	0.047a
Non‐REM% TST	76.39	2.74	74.41	3.96	0.41	0.684
REM% TST	12.10	2.61	5.45	2.73	1.75	0.093
Sleep onset latency (min)	11.92	1.91	18.40	5.26	−1.16	0.263
Wake after sleep onset (min)	10.87	2.69	31.13	6.79	−2.77	0.012a
Total recording time (min)	94.87	0.74	93.76	0.73	1.06	0.297
Sleep efficiency (%)	76.05	3.85	49.31	7.83	3.06	0.006a

^aIndicates P < 0.05, df = 26, corrected for heterogeneity of variance where appropriate.

Abbreviations: min: Minutes; TST: total sleep time; REM: rapid eye movement sleep.