New device may harness benefits of a deep sleep

A NEW discovery could make it possible to take a “power nap” at the flick of a switch.

Scientists have found a way to turn on deep sleep at will using a machine that magnetically stimulates the brain. Such a device worn on the head could in future squeeze the benefit of eight hours sleep into just two or three hours.

The deepest phase of sleep is characterised by slow wave activity. During slow wave sleep, waves of electrical impulses wash across the brain at a rate of roughly one a second. Slow wave activity is known to be critical to the restoration of mood and the ability to learn, think and remember.

Scientists in the US used a technique called transcranial magnetic stimulation (TMS) to induce slow waves in a group of volunteers.

A TMS device sends harmless magnetic signals through the scalp and skull and into the brain, where it activates electrical impulses.

The researchers found that positioning the TMS machine the right way triggered slow waves that travelled throughout the brain.

With each magnetic pulse, the volunteers’ brains immediately generated slow waves typical of deep sleep.

“Creating slow waves on demand could some day lead to treatments for insomnia,” said study leader, Professor Giulio Tononi, from the University of Wisconsin-Madison. “It could also lead to a magnetically stimulated ‘power nap’ which might confer the benefit of eight hours sleep in just a few hours.”