Sleep and memory consolidation

There is some evidence that sleep aids the consolidation of memory.

Network consolidation
Many researchers believe that episodic memories are initially stored in the hippocampus and are slowly moved (or 'consolidated') into the neocortex. This process of consolidation begins during wakefulness and may be enhanced during sleep. Originally it was thought this happens during dreaming (Marr, 1971). However, new research indicates that the NREM phase of sleep is associated with that process (Hobbson, Stickgold, Buzsaki).

Papers

 * Fischer, S., Hallschmid, M., Elsner, A. L., and Born, J. (2002). Sleep forms memory for finger skills, Proceedings, National Academy of Sciences, USA 99, 11987-91.
 * Stickgold, R., James, L., and Hobson, J. A. (2000). Visual discrimination learning requires sleep after training, Nature Neuroscience 3, 1237-8.
 * Wilson, M. A., and McNaughton, B. L. (1994). Reactivation of hippocampal ensemble memories during sleep, Science 265, 676-8.