Figure 1

Experimental schedule.
Time course of the experimental schedule for each group. The intervals between training and retest sessions were 12 h in groups A–D and 24 h in groups E and F. Groups A, B, E and F were trained in the evening (8 p.m.) and groups C and D were trained in the morning (8 a.m.). Groups A and E slept at night as usual, but groups B and F were sleep deprived. Groups C and D performed the experiment in the daytime, whereas group D took a 3-h nap during the training-retest interval (from 1–4 p.m.).