What happens when we go to sleep and begin to dream? Why do some people sleepwalk? Where are they really? Why do we need to sleep at all? These are some of the fascinating questions scientists are starting to answer through sleep research. Their discoveries are changing the way we view the simple act of sleeping.
French and Swiss researchers 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. They 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 “obvious and accurate re-enactment of a short fragment of the recently learned sequence of movements,” the researchers wrote. Read the rest of this entry »