Nov. 6, 2006

Tune-up During Sleep May Boost Memory

Electric Current Improves Memory When Applied During Early Sleep Period, Scientists Say

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(WebMD)  Sleep boosts memory. An electric current that tunes the brain during early sleep can improve memory even more, German scientists say.

During sleep, your brain consolidates the things you learned during the day. When you wake, you can remember these things better than you could the night before. How does this happen?

Memory boosting happens early in sleep, during the period of slow-wave sleep that comes before dreaming and rapid-eye-movement (REM) sleep. During this time, the electric currents in the brain slowly oscillate up and down.

Some scientists say these oscillations are good vibrations that bring brain networks carrying new information into harmony with the rest of the brain. Other scientists say these vibrations are just a side effect of the brain trying to synchronize itself.

Lisa Marshall, PhD, Jan Born, PhD, and colleagues at the University of Lubeck thought of a way to test these ideas. They got 13 brave volunteers — mostly medical students — to let them place electrodes on their heads. While the students slept, the researchers turned on a mild electric current. The pulsing current tuned the student's brains to a slow frequency.

For an hour and a half before going to sleep, the students studied a list of paired words. They were tested just before sleeping and just after waking up the next morning. As expected, the students did better the next morning. But they did even better when their brains were electronically tuned.

"This improvement in retention following stimulation is striking considering that most subjects were medical students, who were highly trained in memorizing facts and already performed well in the sham condition," Marshall and colleagues note.

The brain tuning improved memory only when given during early, slow-wave sleep and not during other phases of the sleep cycle.

The researchers conclude that the slow vibrations of early sleep are not the mere humming of the brain while it works on more important things. Instead, they may be the music of which memories are made.

Marshall and colleagues report the findings in the early online edition of the journal Nature.




SOURCE: Marshall, L. Nature, early online publication, Nov. 6, 2006.



By Daniel DeNoon
Reviewed by Louise Chang
Copyright 2006, WebMD Inc. All rights reserved.
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Add a Comment
by rezinavlag November 7, 2006 4:04 PM EST
One step closer to a BRAVE NEW WORLD.
Reply to this comment
by bluestardad November 7, 2006 9:50 AM EST
hey medical field cure anything prove your worth all the money we spend on your baseless promises! may as well drink snake oil!
Reply to this comment
by November 7, 2006 12:54 AM EST
Oh yeah, zap me!

I can see how this could be abused by college and high school kids, hooking themselves up to batteries with crude timers attached, in order to try to enhance their memory before a test, and electrocuting themselves by accident.

Though it is a cool breakthrough, and I hope they learn a lot of useful things from it.
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