This is Scientific American ― 60-Second Science. I'm Karen Hopkin.Every new parent knows, or learns pretty quickly, that rocking can calm that fussy baby when it's time to take a nap.But the benefits of gentle motion may extend past the swaddling stage.Because two new studies show that rocking also helps grown-ups, both human and mouse, get a good night's sleep.The two research efforts are in the journal Current Biology.What should be no surprise is that movement can be soothing.Think of how many times you've fallen asleep on a train.But can motion really induce a doze, and make for a deeper sleep?To find out, researchers invited 18 healthy volunteers for a sleepover."So they came to the lab and they slept one time on the stationary position, normal bed.And one night where they got rocked."Aurore Perrault, a sleep researcher at the University of Geneva in Switzerland."And what we find is actually compared to a stationary night, a whole night of rocking sleep has a beneficial impact.Not only on sleep initiation, which means they fall asleep faster,but also on sleep maintenance, as we saw that they have less micro-awakening during the night."Subjects who rocked also did better on a memory test the next morning than did the stiller sleepers.In the second study, Konstantinos Kompotis, a postdoctoral fellow at the University of Lausanne, rocked a rack of rodents."Whether rocking affects sleep in species other human was never before discussed.