Rocking puts adults to sleep faster and makes slumber deeper
People’s memories also improved the next day after a night of gentle swaying
Babies love to be rocked to sleep. It turns out that we never quite grow out of it.
Grown-ups tucked into a gently swaying bed for the night fell asleep faster and slept deeper, scientists report in the Feb. 4 Current Biology. What’s more, these rocked adults had sharper memories the next morning. Aside from hinting at the next great sleep aid, the results offer clues about how the brain refreshes itself each night.
“We’ve been rocking our babies for thousands of years now. We know it helps them fall asleep,” says Robert Stickgold, a cognitive neuroscientist at Harvard Medical School. So why not adults? “I’m putting my bed on a rocker tonight,” he says, calling the results “a lot of fun.”
Neuroscientist Laurence Bayer of the University of Geneva and her colleagues first got a hint that adults might benefit from rocking in 2011. The researchers found that adults napped better in a custom-built rocking bed — a contraption that gently sways back and forth every four seconds, moving 10½ centimeters each way. But it wasn’t clear whether rocking might improve sleep across an entire night.
So for the new study, Bayer and her colleagues invited 18 healthy young adults for several laboratory sleepovers, with one night spent on a rocking bed and one night spent on a stationary one. All the while, the researchers measured the people’s brain activity by electroencephalogram, or EEG, which can spot electrical signs of certain sleep stages.