Sound stimulation during sleep can boost memory

Sunday, April 21, 2013 by: David Gutierrez, staff writer
Tags: quality sleep, memory, brain waves

(NaturalNews) Scientists from the University of Tubingen, Germany, have discovered a technique to improve both sleep and memory at the same time by playing sound waves attuned to the frequencies of the brain's oscillations, according to a study published in the journal Neuron.

"The beauty lies in the simplicity to apply auditory stimulation at low intensities," said co-author Jan Born, "an approach that is both practical and ethical, if compared for example with electrical stimulation - and therefore portrays a straightforward tool for clinical settings to enhance sleep rhythms."

The researchers hooked up 11 sleeping participants to an electroencephalograph (EEG) to record their brain wave oscillations. The intervention took place while the participants were undergoing the slow oscillations of slow-wave sleep. These oscillations have previously been associated with the memory-forming functions of sleep.

On one occasion, the researchers played random sound waves, while on another they played sound waves identical in frequency to the brain's slow oscillations.

"We presented the acoustic stimuli whenever a slow oscillation 'up state' was upcoming, and in this way we were able to strengthen the slow oscillation, showing higher amplitude and occurring for longer periods," Born said.

Consumer application "should be easy"

The researchers found that when exposed to the synchronized sound waves, participants not only slept better, but also were better able to remember a word association they had been given before going to sleep.

"Importantly, the sound stimulation is effective only when the sounds occur in synchrony with the ongoing slow oscillation rhythm during deep sleep," Born said.

The findings have an obvious application in improving both sleep and memory, the researchers said.

"It might be even used to enhance other brain rhythms with obvious functional significance - like rhythms that occur during wakefulness and are involved in the regulation of attention," Born said.

Unfortunately, because the technique requires synchronizing sounds with a patient's brain waves, it cannot currently be performed at home.

"The method cannot be applied by everyday people, at the moment," Born said, "because the essential point is the 'closed-loop' fashion of our stimulation, using the brain's own rhythm as a pacemaker."

"Of course, basically it should be easy to develop a device that records the EEG and searches the record online for the occurrence of a slow oscillation and then delivers acoustic click stimuli," he said. "Maybe there will be a company adopting the approach to make some money out of it."

Good sleep "essential" to memory formation

A large body of research suggests that sleep plays a critical role in memory formation and processing.

"We've learned that sleep before learning helps prepare your brain for initial formation of memories," said sleep scientist Matthew Walker of the University of California-Berkeley. "And then, sleep after learning is essential to help save and cement that new information into the architecture of the brain, meaning that you're less likely to forget it."

Cognitive processes that take place during REM sleep, while dreaming, also appear to help link new memories to older, related ones.

(Natural News Science)

Sources for this article include:

http://www.natureworldnews.com

http://www.eurekalert.org/pub_releases/2013-04/cp-ssd040513.php

http://www.firstcoastnews.com

http://newsinhealth.nih.gov/issue/Apr2013/feature2