As reported by The Hartford Courant, January 3, 2006.

As You Sleep, Your Brain Keeps Working

By Susan Campbell

Think of the possibilities: You're heading to Munich in a month, and you want to learn German. There's no time for classes, but if you can play language tapes that promise to teach you while you sleep, you can effectively accomplish seven or eight hours each night.

You'll be brilliant, the envy of everyone.

And you'd be dreaming. Or, rather, you should be dreaming, and not trying to cram while sleeping. Those seductive ads that promise that you can learn while you sleep are bogus. Sleep involves specific brain activity that circumvents the processing of new information. So if you're trying to learn a new language, cram for a test, or learn any new skill, better to study during the day, and then just sleep on it.

"If it sounds too good to be true, it probably is," said Edward O'Malley, director of Norwalk Hospital Sleep Disorders Center. "We all think we're super-duper beings, but none of it's true. We're all biological beings with biological limits. Until we can grow extra heads and extra brains, that is what we can expect."

In fact, our one, single brain performs amazing stuff, even at rest. A recent study from Beth Israel Deaconess Medical Center shows that MRI scans reveal brain regions shifting dramatically during sleep, almost like the brain is working to store memory efficiently. Because of this storage, upon awakening the subject is able to recall newly learned tasks quicker and more accurately. So the connection between sleeping and learning is huge - but researchers say sleeping augments learning. It doesn't facilitate it. (And this isn't just for humans. Similar brain studies show that rats who've been trained to run tracks do so in their heads during sleep, and zebra finches replay songs while sleeping - possibly to store them in memory.)

During sleep, the brain goes through several periods of activity, including REM sleep, or rapid eye movement, when dreams occur. The older the sleeper, the less amount of REM sleep needed. In deep sleep - sometimes called delta sleep - brain cells begin to fire in concert. Think of it as millions of football fans doing the wave around a stadium. To interrupt that with, say, a language tape, is to ask the brain to change tracks and perform a completely different activity.

"There's a point where brain waves change, and where it takes a greater-than-normal stimulus to get someone's attention," said Daniel McNally, medical director at the Sleep Disorders Center at UConn Health Center. For people who play nighttime tapes, "they're having a light and fragmented sleep and during that light and fragmented sleep, it's not a good thing." The brain can neither process the new information, nor store information collected during the day.

For example, McNally suggests thinking of the evenings you've fallen asleep in front of the television. The average sleeper will wake up at 2 or so, groggy and vaguely sick to his or her stomach. Yet McNally said UConn has clients who leave the television on because they insist they need background noise to fall asleep.

"But while it's on, the odds are there are more arousals, more awakenings, and the brain's reacting to the noises," said McNally.

But if the brain at rest isn't able to absorb new information, the brain approaching rest can, said O'Malley.

"Where this all comes from and why it's been this sort of persistent urban myth is that during the twilight stage, when you're drifting in and out of sleep, you're in a data state, a state in which you do have some awareness," said O'Malley. "Your fact-checking mechanism is off-line, and you absorb information quite readily."

But that twilight time lasts only a few minutes - or seconds, depending on the level of tiredness.

On the other hand, according to the National Sleep Foundation, lack of sleep impairs the ability to pay attention, communicate, think, and it affects mood, among other things. Some tasks - rule-based or logical, in particular - may not be as affected by sleep deprivation. But daytime learning is enhanced by sleep, said Asher Qureshi, director of St. Francis Hospital and Medical Center's Sleep Disorders Center.

"Let's say I'm trying to memorize three sentences while I'm awake, and then during REM sleep, my brain will consolidate the memory," said Qureshi. "Even 10 years from now, we can recall them without any problems. Like when you're learning a new address, for the first couple of days you have difficulty, but after a while it's automatic."

"That's the nifty part," said McNally. "People are always asking, `Why do we need sleep,' and if we can point to something sleep really does, as opposed to sleep keeping you from being tired - a negative side - then they're more excited. You need sleep."