A rocking motion — like that from a hammock — leads to better sleep and boosts memory, new research shows.
Like a child gently rocked to sleep in cradle, adults also respond to a rocking motion during sleep.
People in the study being rocked to sleep fell asleep quicker.
They also slept more soundly and consolidated memories more effectively.
The bed rocked gently from side-to-side once every four seconds by about 10 cm.
Dr Laurence Bayer, study co-author, said:
“Having a good night’s sleep means falling asleep rapidly and then staying asleep during the whole night.
Our volunteers — even if they were all good sleepers — fell asleep more rapidly when rocked and had longer periods of deeper sleep associated with fewer arousals during the night.
We thus show that rocking is good for sleep.”
The study included 18 people whose sleep was monitored in the lab.
The results showed that those who slept on a gently rocking bed went to sleep more quickly, slept more soundly and had better memories when they awoke.
Further investigations showed that gentle rocking motions during sleep help to synchronise neural activity in the thalamo-cortical regions of the brain.
This area is critical for memory consolidation and sleep.
The authors conclude that:
“…applying a rhythmic sensory stimulation, here, using a rocking bed during a whole night of sleep, promotes deep sleep and memory consolidation in healthy sleepers.
These effects may rely on increased SOs and sleep spindles (i.e., fast spindles), which we suggest are attributable to a rocking-induced rhythmic entrainment of thalamocortical activity.”
A previous study has also shown that a rocking motion makes a 45-minute nap more refreshing.
So, taking a nap in a hammock may be better than sitting in an ordinary chair.
The study was published in the journal Current Biology (Perrault et al., 2018).