Study Finds That Sleepwalkers Learn by Going Through the Motions
Whatâ€™s the News: By videotaping sleepwalkers as they got some shut-eye, French and Swiss researchersÂ caught on tape what other studies have deduced through brain recordings and memory tasks: As we sleep, our brains seem to replay what we learned during the day.
How the Heck:
- The researchers recruited 19 sleepwalkers and 20 people with sleep behavior disorder, who physically act out their dreams, plus 18 people without any sleep disorders.
- All the subjects learned a physical skill: hitting particular buttons arrayed around them in response to different prompts from a computer.
- The researchers then videotaped each person as they slept. One of the sleepwalkers lifted her arms during REM sleep and started moving her hands in a familiar pattern: an â€œobvious and accurate re-enactment of a short fragment of the recently learned sequence of movements,â€ the researchersÂ wrote.
Whatâ€™s the Context:
- AÂ whole lot of research has suggested that a good nightâ€™s sleep can improve memory not just for physical tasks like this one, but for words, facts, pictures, and spatial information.
- Most of these studies have compared how sleep-deprived and well-rested people performed on memory tests, or looked at how closely brain activity during sleep resembled brain activity as people learned something new.Â Watching people who act out their thoughts as they sleep provides a more direct view of what the brainâ€™s up to.
Not So Fast:
- Some scientists think that sleepâ€™s impact on memory isnâ€™t as simple as locking down everything weâ€™ve learned. Sleep may only solidify memories when we know weâ€™ll be tested, or may actually help us prune unimportant memories rather than fortify the important ones.
- OthersÂ arenâ€™t convinced that sleep helps us solidify memories at all; they argue that,Â at best, we can cement what weâ€™ve learned as well while sleeping as we can while weâ€™re awake.
Photo: Chad Fitz, WikimediaCommons