Would you swap your bed for a hammock? Being rocked induces a better night’s sleep in adults as well as babies AND boosts memory, study suggests
- Continuous rocking for 45-minute helped gave people a better night sleep
- The motion reduces ‘micro-wakes’ – brain activity that creates a restless night
- It could lead help insomniacs and boost memory before an exam, experts said
Being rocked to sleep does not just work for babies.
Adults trying to sleep better may want to consider investing in a hammock to benefit from the same effect.
Scientists have found people who are gently rocked from side to side at bedtime fall asleep faster and get more restful deep sleep.
So good is their slumber that their memories are even better the next day.
Researchers led by the University of Geneva asked 18 adults to spend a night in both a normal bed and one which rocked from side to side.
When in a moving bed, people fell fully asleep six minutes faster and were less likely to wake up in the night, having fewer ‘micro-wakes’.
People rocked to sleep could find they do better at work or school the next day, as sleep plays a vital role in retaining information.
Scientists have found people who are gently rocked from side to side at bedtime fall asleep faster and get more restful deep sleep
Asked to memorise 46 pairs of words, they remembered an additional three words on average.
Experts believe the motion of being rocked synchronises the brain waves which control sleep. We may have evolved to sleep better this way because as babies we were rocked back and forth in the womb.
Dr Laurence Bayer, who led the research from the University of Geneva, said: ‘A good night’s sleep means falling asleep quickly and staying asleep all night. However, we observed that our participants, although they slept well in both cases, fell asleep more quickly when they were rocked.
‘In addition, they had longer periods of deep sleep and fewer micro-wakes – a factor frequently associated with poor sleep quality.’
Babies have long been cradled and rocked by their parents to help them get to sleep.
Researchers have previously found the same thing works for adults who are rocked during short naps, and this could explain why it is so easy to fall asleep in moving cars and trains.
In the new study, people were monitored through the night, to see how rocking affected deep sleep.
Sleep trackers showed they fell asleep, after the first drowsy stage of drifting off, six minutes faster when in a rocking bed than a normal one.
They also got more deep sleep, known as the N3 stage of sleep, which is crucial for storing memories.
To test that this had improved the sleepers’ memories, researchers gave them 46 pairs of words to memorise, testing how many they remembered before bedtime.
Following a good night’s sleep someone remembers more of what they have learned the previous day, making everything from exam revision to long-term work projects easier.
And indeed people rocked to sleep remembered an extra 4.7 words than they had they had the previous evening. That compared to only an additional 1.5 words for people in a stationary bed.
The study, published in the journal Current Biology, measured ‘micro-wakes’ which take place when the brain kicks into gear during the night. We are not aware of them, and they last only three to 11 seconds, but they disturb sleep and raise the risk of waking up at night.
People rocked to sleep had 35 fewer micro-wakes during the night, improving their sleep quality.
They spent more than 27 per cent of their night in deep sleep, compared to just over 22 per cent when not rocked to sleep.
The researchers say a rocking motion may activate the vestibular system which controls balance and may also benefit brain waves.
It could lead to a treatment for insomniacs and elderly people with sleep problems.
They conclude: ‘Sensory stimulations may disrupt or enhance sleep – just think of the traffic noise that keeps us awake, whereas the gentle sway of a hammock may soothe us to sleep.’