Even adults sleep better after being rocked

A pair of new studies might inspire you to keep the time when you were rocked by your parents. Studies have shown that for both mice and healthy young people, a slight rocking motion before and during sleep leads to deeper sleep. And in humans, the swinging seemed to even improve their memory skills afterwards.

Most people who have had a child crying in their arms know that rocking seems to help them calm and calm them. But some sleep scientists have begun to study whether rocking could be useful long after we left the cradle. In 2011, for example, Swiss researchers published a study showing that people who slept on a gently rocked bed were able to fall asleep more quickly and spent more time in a deep sleep phase than when they were sleeping. they slept on a normal bed. Some of these same researchers have collaborated with others for these latest studies, both published Thursday in Current Biology.

In the human study, 18 young volunteers (aged 23 on average) spent three nights in a sleep laboratory, where their brain waves and sleep patterns were monitored. The first night, they got used to sleeping in the lab. And then, in a random order the next two nights, the volunteers slept either as usual, or in a bed that was gently tilted from one side to the other with the help of d & rsquo; An engine.

Overall, compared to the night of normal sleep, volunteers no longer slept. But they seemed to have a deeper sleep, indicated by the longer time spent in the 3rd phase of non-REM sleep. (In general, we review three phases of non-REM sleep, then several times a night.) They also experienced fewer abrupt changes in brain patterns, or awakenings. These wakefulness changes signal the transition from deep sleep to light sleep, or from sleep to waking up.

"In practice, a slight lateral swing helps to fall asleep and, at least, to humans, to spend more time in a deeper sleep," University researcher Konstantinos Kompotis told Gizmodo. of Lausanne in Switzerland and co-author of both studies.

We need sleep for a lot of reasons, but among these things help us remember the most recently stored memories, or what scientists call consolidation of memory. Researchers had therefore hypothesized that sleep badisted by switching would indirectly lead to greater consolidation of memory. And of course, the volunteers did a better job of simply memorizing words after dark.

Kompotis and his team were also able to observe some of these tipping effects in the mice studied. This is the first study that shows that tipping can help non-human animals sleep better, according to the authors. But there were some differences. Mainly, it took a faster tilting movement with the mice to see any positive increase in sleep. In both studies, they were also able to identify some of the possible reasons why swinging improves sleep.

"In mice, it seems that sway acts through the vestibular system (the sensory system responsible for balance and spatial orientation) and impinges directly on sleep patterns, preventing mice from staying awake, "said Kompotis. In humans, he added, the rhythmic structure of the sway could cause our brain to synchronize in such a way as to increase the frequency of patterns of brain activity important for deep sleep and sticky memory, a phenomenon as well. called training.

Kompotis and his team were not content to jostle volunteers to fall asleep for pleasure. Understanding how our brains interact with the outside world before and during our sleep is important to understanding how to help people who, for one reason or another, can not sleep soundly. And it's possible that rocking could be used to treat people with insomnia, age-related sleep disorders, and "other sleep disturbances, as well as memory loss," Kompotis said.

"I am interested in finding non-pharmacological treatments for sleep disorders and why not one day the rocking bed?", Co-author Aurore Perrault, researcher at the Sleep, Cognition and Neuroimaging Laboratory of Montreal, Canada.

When I asked Kompotis if his team's findings should encourage people with insomnia to get a hammock, he replied, apparently with a tongue in his cheek, that he would consider it personally. But there is still a lot of research to be done.

"I know I'll do it, I've always wanted a hammock!" He said. "On a more serious note, I would first of all wait to better understand the brain structures involved and to have tested the sub- and supra-optimal parameters of tipping in humans, so as to be able to use the maximum and the least possible . only beneficial impact of rocking on sleep. "

The effects of rocking can also be different when we try to nap rather than sleep for the night. And that could come from the type of flip-flop movement used; a swivel hammock is different from the fixed motion, more like a tremor, from the bed that they created.

In other words, we need to determine the degree of smoothness and speed with which this swing should be optimal to make the most of its effects on sleep.