What is the role of sleep and knowledge in motor skill learning?

Abstract

Mounting evidence demonstrates that sleep plays an important role in learning a new motor skill. However, receiving explicit knowledge of the skill prior to learning may influence the beneficial role of sleep in the consolidation of this memory. To assess the role of knowledge in motor skill memory consolidation, we used the Serial Reaction Time (SRT) task, which involves learning a sequence of key presses using a computer keyboard. Subjects (N=40) practiced the task at either 8:00 am or 8:00 pm and returned for a retention test at either 8:00 pm the same day (no-sleep group) or 8:00 am the following morning (sleep group). Half of the subjects received no knowledge or instructions regarding the presence of a sequence prior to practice (implicit condition) while the other half received explicit instruction of the sequence to be learned (explicit condition) prior to testing. The results indicate that both type of knowledge (either implicit or explicit) as well as sleep influence motor skill learning. Explicit knowledge of a motor skill appears to enhance performance following a period of sleep compared to a similar period of being awake where as having no explicit knowledge of the task does not appear to alter learning following either sleep or no-sleep but may stabilize performance between practice and retention. In conclusion, gaining a better understanding of the effects of sleep and knowledge on the consolidation of new motor memories could change the manner in which skills are taught and, potentially, relearned following neurological injury.