Nap time

"Figure 4. The difference in each participant's average performance at 8 and 22 h post-training (PT) from his or her own average 0 h PT performance speed, normalized to the 0 h PT performance. Data for participants in the four groups, NapNoInt, NapNoInt, NoNapNoInt and NoNapInt, are shown. Positive values indicate delayed gains in the task performance, whereas negative values correspond to the slowing down of the performance speed relative to the immediate post-training level."

From a very nice paper from Korman et al., Daytime sleep condenses the time course of motor memory consolidation, in the latest issue of Nature Neuroscience.