The secrets of sleep
It's a mystery, but it clearly makes us smarter and healthier
Health education teacher Pacy Erck remembers what it was like back when Edina High School students had to show up by 7:25 a.m. "The kids were always very tired," she recalls. But these days, Erck rarely has a kid nod off in class. That's because in the fall of 1996, officials at this Minnesota school decided to ring the first bell an hour later, at 8:30 a.m. Sleep researchers had reported that teens' natural slumber patterns favor a later bedtime, and the school wanted to ensure that its high schoolers weren't being shortchanged by an early wake-up call. The change means that students average five more hours of sleep a week, and teachers can see a difference. "You don't have the kids putting their heads down," Erck says. "The class is livelier."
Research confirms real benefits not only at Edina but also at many other high schools that have made similar scheduling switches, says Kyla Wahlstrom, an education policy expert at the University of Minnesota-Twin Cities. Grades have gone up, and dropout rates have declined. The results are impressive enough that other school systems have started to take notice. In Poquoson, Va., the school board has held public hearings over the past few months to consider making the first bell later. "We do believe our children aren't getting as much sleep as they ought to," says Jonathan Lewis, superintendent of schools in Poquoson. "We have children getting up at 5:30, quarter of 6 in the morning."
But what is it about getting more sleep that's actually helping students do better? Is it just that sleepy kids can't concentrate in class because they're dozing off over their books, or does something happen in dreamland that affects the brain's ability to learn and remember?
A growing number of scientists suspect that sleepless students may suffer more than just feeling dragged out during the day. Many intriguing studies in both humans and animals suggest that the sleeping brain does something to solidify memories and process newly learned lessons. The brain work of sleep may even allow people to form insights that they can't achieve while awake, according to research that gives new weight to the old notion of taking a tough problem and "sleeping on it." With most Americans routinely getting far less sleep than they should, some experts are starting to wonder if widespread sleep deprivation is having a real but unrecognized effect on society's brainpower and creativity.
Sleep is clearly important--after all, people and animals slumber away a third of their lives--but no one knows why. The special learning potential of sleep is an idea that has long held sway in the popular culture: Consider those sketchy "learn while you sleep" audiotapes that promise to "tap into the power of your unconscious." But hard scientific evidence has been scant until recently. Most sleep research has focused on health, and sleep has been viewed mainly as a period of rest and rejuvenation for the body.
That's why, for decades, most experts dismissed sleep as a boring, idle time for the brain. What they didn't realize is that while sleeping bodies lie motionless in bed, the brain's neurons continue to buzz and chatter. Only with the 1953 discovery of rapid eye movement (REM) sleep and the development of new machines to monitor brain activity did researchers begin to see what, exactly, was going on at night. Suddenly they could watch as the brain moved through predictable cycles of REM sleep--with its sometimes vivid dream imagery--and deeper "slow wave" sleep.
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