Table 1. Sleep architecture.

	Control night	Learning night	Statistics
Sleep latency	21 ± 19 min	16 ± 9 min	NS*
Total sleep time	419 ± 70 min	440 ± 52 min	NS*
Sleep efficiency	89 ± 5.7%	91% ± 7.1%	NS*
Duration of the 1st cycle	88 ± 20 min	104 ± 37 min	Duration of the cycles (Condition × Cycle ANOVA) Condition: F(1,13)=.28291, p>0.05 Cycle: F(2, 26)=.45059, p>0.05 Condition × Cycle: F(2, 26)=3.2374, p>0.05
% of 1st Cycle that is NREM	78 ± 7%	72 ± 10%
Duration of the 2nd cycle	118 ± 52 min	91 ± 28 min
% of 2nd Cycle that is NREM	72 ± 17%	72 ± 15%
Duration of the 3rd cycle	99 ± 28 min	101 ± 28 min
% of 3rd Cycle that is NREM	79 ± 15%	79 ± 13%

Values expressed as mean ± standard deviation.

^*Non-significant (p>0.05, paired t-test)