Daytime Naps Promote Skilled-movement Learning

Whether you are learning to play the piano or learning to throw a football to a fast-breaking receiver, the necessary muscle movements have to be memorized. Converting the memory of movements into long-lasting form takes several hours or more for the brain to "consolidate" the learned movements. This process can be disrupted by trying to learn a different movement during this vulnerable period. For example, consolidation of the memory for a few chords on the piano can be disrupted by trying to learn finger movements on a computer keyboard during this consolidation period.

Another feature of motor learning is that delayed gains in skill performance can occur after a latent period of several hours after an effective learning experience. This delayed performance gain depends on the first post-training night's sleep (I have explained the role of sleep on other kinds of memory in my book on improving memory.

Now comes a study that shows that daytime naps condense the time course of motor- memory consolidation. In the experiment, subjects learned a five-element finger-to-thumb opposition sequence with their non-dominant hand. Then the experimenters tested the effect of a post-training nap. Compared to no-nap controls, a 90-minute daytime nap immediately after training markedly reduced the susceptibility to post-training interference effects and produced a much earlier expression of delayed gains within 8 hours post training. Thus, both memory-enhancing effects were produced by the nap.

Would a shorter nap produce the same effect? We don't know. It wasn't tested. Another untested possibility is that the daytime nap might enhance the memory consolidation that is normally produced by a night's sleep after a motor learning experience, especially if the task is rehearsed that same day after the nap.

Source:

Korman, M. et al. 2009. Daytime sleep condenses the time course of motor memory consolidation. Nature Neuroscience. 10 (9): 1206-1213.