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“Suppose you’re working on a problem and you’re stuck,” [Lewis] says. In REM sleep, “the neocortex will replay abstracted, simplified elements [of that problem], but also other things that are randomly activated. It’ll then strengthen the commonalities between those things. When you wake up the next day, that slight strengthening might allow you to see what you were working on in a slightly different way. That might just allow you to crack the problem.”
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Essentially, non-REM sleep extracts concepts, and REM sleep connects them.
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Her team tried to get sleeping volunteers to replay memories during slow wave sleep and REM sleep, and found different effects in each. Those results should be published in the near-future. In the meantime, the team is also developing ways of boosting or suppressing the two sleep stages to see how that affects people’s problem-solving skills.
Read full, original post: A New Theory Linking Sleep and Creativity