Playing synchronized sounds during sleep can boost memory

Last Updated: Apr 12, 2013, 13:01 PM IST

Washington: Slow oscillations in brain activity, which occur during so-called slow-wave sleep, are critical for retaining memories, a new study has revealed.

Researchers have found that playing sounds synchronized to the rhythm of the slow brain oscillations of people who are sleeping enhances these oscillations and boosts their memory.

This demonstrates an easy and noninvasive way to influence human brain activity to improve sleep and enhance memory.

"The beauty lies in the simplicity to apply auditory stimulation at low intensities-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," coauthor Dr. Jan Born, of the University of Tubingen, in Germany said.

Dr. Born and his colleagues conducted their tests on 11 individuals on different nights, during which they were exposed to sound stimulations or to sham stimulations.

When the volunteers were exposed to stimulating sounds that were in sync with the brain`s slow oscillation rhythm, they were better able to remember word associations they had learned the evening before.

Stimulation out of phase with the brain`s slow oscillation rhythm was ineffective.

The researchers suspect that this approach might also be used more generally to improve sleep.

The study is published online in the Cell Press journal Neuron.