Table 1.

Sleep data

	Experiment 1		Experiment 2
	Expected	Unexpected	Expected	Unexpected
Total sleep time	446.79 ± 6.40	445.87 ± 10.54	442.17 ± 6.34	454.40 ± 5.32
Wake	0.64 ± 0.27	1.67 ± 0.88	1.82 ± 0.71	0.52 ± 0.15
Stage 1	6.19 ± 0.98	5.37 ± 0.71	6.07 ± 1.95	6.36 ± 0.83
Stage 2	49.73 ± 1.99	53.41 ± 2.38	49.66 ± 2.99	55.98 ± 2.61
Stage 3	11.15 ± 1.06	11.66 ± 0.65	9.79 ± 0.96	9.69 ± 1.44
Stage 4	8.20 ± 1.43	4.07 ± 1.16*	11.72 ± 1.81	5.11 ± 1.41**
SWS	19.35 ± 1.64	15.73 ± 1.55	21.51 ± 2.49	14.80 ± 2.13
REM	22.86 ± 1.02	22.84 ± 1.60	20.00 ± 1.89	20.84 ± 1.11
SWS latency	18.68 ± 2.10	20.03 ± 1.32	16.06 ± 1.55	18.15 ± 2.43
REM latency	88.64 ± 9.38	77.13 ± 4.57	81.50 ± 5.38	90.45 ± 10.40

Data for mean (± SEM) total sleep time, time spent awake, stage 1 sleep, stage 2 sleep, stage 3 sleep, stage 4 sleep, slow wave sleep (the sum of stage 3 and 4 sleep) and REM sleep given in percentage of total sleep time, and latency of the first period of SWS and REM sleep (with reference to sleep onset) are shown;

* p < 0.05,

** p < 0.01, for differences between groups.