Rocking adults to sleep

Sleep is essential for a healthy life. Without it, issues such as heart disease, diabetes and high blood pressure start to creep in. But could rocking adults to sleep improve all that?

Imagine a crying baby late at night. You get up to take care of them, pick them up and rock them, which causes the baby to relax and go to sleep. Most of us have been on one end, if not both, of this scenario. But at a certain point in our childhood, we learn to sleep on our own, and the rocking ends.

“Rocking simulation is very beneficial for sleep: it increases sleep initiation (which means they fall asleep faster), sleep maintenance, and also they spend more time in deep sleep,” comments Aurore Perrault, from the University of Geneva, who studied the beneficial effects of rocking adults to sleep. But let it be known, the participants weren’t quite settling down in an adult-sized cradle.

The experiment involved that they rest on a bed that would gently move from left to right on a track, rather than swaying or tilting. All participants spent three nights at the lab: one to get used to the settings, one on a stationary bed, and one on the rocking bed.

The study on adult humans had another positive outcome: the test subjects had three times better memory after waking up from sleep in the rocking bed. Their memory was tested through a series of paired word associations taught before sleep, and upon waking up, researchers told them one of the words and asked for the other.

Published in Current Biology, Aurore’s experiment showed that parts of the brain synchronise with the rocking motion which led to multiple benefits.And why would this be? "We probably sleep better when rocked because the rocking motion drives the brain to work in a rhythm, which in turn boosts sleep through less arousal and therefore, better sleep maintenance," says Aurore.

A parallel study in mice also supported the results. It showed that mice also slept faster and longer on rocking beds, although it did not improve their deep sleep, as was the case with humans.

One in three people suffers from poor sleep in the UK and in America, according to the NHS and CDC, respectively. This has direct and indirect implications for their health, but it is very harmful to the economy as well. Think medical costs, loss of productivity, and time off work from fatigue or injuries. “We are now wondering what would happen long-term,” says Aurore, “are the benefits sustained, or would there be some arbitration effect so that there is no longer beneficial effects on sleep? We don’t know right now and that’s something we’d like to test”.

Maybe we shouldn’t lose our sleep over it - after all, these are promising results to improve sleep in a non-pharmaceutical way.