Sleep-Dependent Learning: a Nap is as Good as a Night
Mednick, S., Nakayama, K., Stickgold, R., Nature Neuroscience, published online June 2003
“We now report that sleep-dependent learning of a texture discrimination task can be accomplished in humans by brief (60-90 min) naps containing both slow-wave sleep (SWS) and rapid eye movement (REM) sleep.”
The Restorative Effect of Naps on Perceptual Deterioration
Mednick, S., Nakayama, K., et. al., Nature Neuroscience, published online 28 May 2002,
“Here, we tested human subjects four times in one day and found that with repeated, within-day testing, perceptual thresholds actually increased progressively across the four test sessions. This performance deterioration was prevented either by shifting the target stimuli to an untrained region of visual space or by having the subjects take a mid-day nap between the second and third sessions.”
The Effects of a Short Daytime Nap After Restricted Night Sleep
GILLBERG M, KECKLUND G, AXELSSON J, AKERSTEDT T., Sleep, 1996;19(7):570-5.
“The aim of the present study was to examine the effects of short naps (less than 20 min) at noon for five consecutive days. Seven young adults (21-24 yrs) who had normal sleep-wake habits without habitual daytime napping participated in both the Nap and the No-nap conditions. During the Nap week between Monday and Friday, the subjects went to bed at 12:40 and were awakened at 13:00. During the No-nap week, they read a newspaper, sitting on a semi-reclining chair during that time. Subjective sleepiness and fatigue were evaluated immediately before and after napping and twice in the mid-afternoon (14:40 and 16:30).”