SSS 2011-06-20（在线收听）

This is Scientific American’s 60-Second Science. I’m Cynthia Graber. This will just take a minute.

You’re lying in a hammock by a breezy shore. The hammock rocks softly back and forth. In no time…(snoring). It turns out that’s not just the relaxation of being on vacation that’s bringing on sleep. It’s the rocking hammock. That might not be a huge surprise—babies get rocked to sleep. But researchers wanted to know how rocking works.

They recruited 12 healthy males, all good sleepers. Each volunteer twice took an afternoon nap in a dark room on a custom-made bed that could rock. For one nap, the bed was still. For the other, it rocked gently.

All the men fell asleep faster when they swayed. And the scientists monitored the men’s brain activity during all the naps. They found that rocking increased the duration of what’s called N2, a non-REM stage that accounts for about half of a good night’s sleep.

Rocking also increased deep-sleep-associated brain activity—so-called slow oscillations as well as bursts of action called sleep spindles. The research was published in the journal Current Biology.

The next step is to find out whether rocking can help treat sleep disorders. Meanwhile, insomniacs can always try a hammock.

Thanks for the minute. For Scientific American’s 60-Second Science, I’m Cynthia Graber.