Better memory, creativity and intellectual performance seem to get a boost from sleep

Get enough sleep — whatever that means for you — and you're likely to ace that test, think more creatively, have better long-term memory and preserve important memories.

That's the bottom line behind a spate of recent studies.

But why sleep has those effects and how that information can be used to your advantage are questions still under study, says Robert Stickgold, an associate professor of psychiatry at Harvard Medical School.

“The sleeping brain is not stupid,” says Jessica Payne, an assistant professor of psychology who has researched the effect of sleep on memory. “It's smart, and it's making sophisticated decisions about which memories are important and should be held onto.”

Yet, why sleep is so crucial for memories remains a big mystery, Payne and Stickgold agree.

Sleep helps in the whole information-processing part of the picture. “It might be that sleep is an amount of time to give the brain a chance to go offline and shift into a different psychological mode that's evolved to perform certain types of memory processing,” Stickgold says.

Though there's still much to be learned, research suggests that REM (rapid eye movement) sleep seems to be the phase that resolves the issue, or tells you what to do with new information.

Someone who can't decide whether to take up a new job, Stickgold says, opts to sleep on it.

Payne says she's found that a good night's sleep can lead to better inferential ability.

“Sleep is not only important for your ability to remember,” she says, “but it also helps you be more creative, find more interesting and distant connections and be more innovative.”

As for how to convince us that a good night's sleep is a worthy goal, Stickgold says that no one has “come up with the right ad campaign yet” to convince people to get enough sleep.

In truth, he says, sleep deprivation has been linked with obesity because it disrupts insulin regulation, in turn easing weight gain. And, the sleep-and-illness and sleep-and-memory links are well known.

Though the amount of sleep needed does vary, Stickgold has an easy test to decide if you're getting enough.

“Watch what happens on the weekend if you don't set an alarm,” he says. “If you sleep more than you sleep during the week, you aren't getting enough sleep.”

Getting an extra hour or two of sleep a night can pay big — and perhaps, even life-saving — benefits.-NYT