Most any person who’s had a crying child in their arms knows that rocking seems to help calm and eventually sedate them. But some sleep scientists have started to study if rocking can be useful for us long after we’ve left the crib, reports Gizmodo.
In 2011, for instance, researchers from Switzerland published a study showing that people who grabbed an afternoon nap on a gently rocking bed were able to fall asleep faster and spent more time in a deep phase of sleep than when they napped on a regular bed. Some of those same researchers collaborated with others for these latest studies, both published Thursday in Current Biology.
In the human study, they had 18 young volunteers (average age 23) spend three nights at a sleep lab, where their brain waves and sleep patterns were monitored. The first night got them used to sleeping at the lab. And then, in a random order over the next two nights, the volunteers either slept as usual, or slept in a bed that was gently rocked from side to side with the help of a motor.
Overall, compared to the normal night of sleeping, the volunteers didn’t sleep any longer. But they did seem to have more deeper sleep, indicated by the longer amount of time they spent in the 3rd phase of non-REM sleep. (Typically, we cycle through three phases of non-REM sleep, then REM sleep, several times a night.) They also experienced fewer moments of abrupt shifts in brain wave patterns, or arousals. These shifts in arousal signal a change from deep to light sleep, or from sleeping to waking up.