Baby won't sleep How do you put him to sleep? "Back switch" approaching with science

"You won't sleep tonight," "When will you stop

crying?"

A researcher raising four children has taken on the challenge of finding a scientific answer to a question that has never had a clear answer.

Then, there is also a surprising discovery that overturns that commonly known “back switch”.

This is the result of research that I would like parents who are troubled with falling asleep or crying at night to know.

I've put together some "sleep tips" below.

The starting point is the researcher's own difficulties in raising children

A research group led by Dr. Kumi Kuroda of the RIKEN Center for Brain Science has challenged the science of putting a crying baby to sleep.

She is Kuroda, who is also the mother of four boys.

It is said that the starting point for this research theme is the hardships of raising a child for the first time.

“It was the first time my husband and I were raising children, so it was really hard not knowing why we were crying. I've always wanted to know what would help my baby stop crying and put him to sleep, because he wouldn't sleep at night."

In addition to piggybacking and cuddling, there are other ways to make babies stop crying, such as using a cradle, and wrapping a baby in a cloth called "swaddling," which is said to be effective depending on the region, culture, and family. it's different.

Mr. Kuroda thought that if the effects could be demonstrated scientifically, rather than based on intuition or conventional wisdom, he would be able to help parents who are worried about raising children.

"What seems to be the right method for me may not be the right one for other parents, and I may be under the impression that it works in the first place. If that's the case, I don't know what is the most effective way to get my baby to sleep. I decided to investigate the facts scientifically, because it is difficult for any parent to raise their first child.”

Could it be... will it become quieter when you carry it?

Kuroda's research focuses on strong feelings between parents and children, such as parents protecting and raising their children, and children admiring their parents.

From my experience raising my first child, I had a vague feeling that walking in the arms might be effective in stopping crying babies. I got

"When I clean the mouse cages used in the experiment, I need to transfer the baby mice. Mice jump around and are hard to catch. I had an epiphany that the same could be said for human babies.I looked up previous research, but almost no one had done so, so I decided to do my own research.”

After that, Dr. Kuroda discovered a phenomenon in which babies become quiet while being carried, such as by walking around in their arms.

This reaction is said to be seen not only in humans but also in other mammals such as cats and lions.

Kuroda believes that this is an instinct that has been learned to keep the young of wild animals quiet and not increase the danger, as they are often carried away by their parents when foreign enemies are approaching. increase.

Mr. Kuroda found that “walking in the arms” is effective.

In addition, we decided to investigate under what conditions it would be effective to stop the baby from crying by changing the situation and time.

My child also participated in the experiment.

This is an experiment conducted by Kuroda's group.

It started more than 10 years ago in parallel with experiments to investigate "transport reactions."

In the experiment, 21 pairs of babies aged 7 months or younger and their mothers were given 4 types of motions: ▽“

Walk while holding”, ▽“

Move in a stroller”,

▽“Sit while holding ”, ▽“Lie on a

bed”. Have them perform a combination of movements for several tens of minutes.

We recorded movements in 30-second increments and observed the baby's state at that time, such as whether or not he was crying.

Mr. Kuroda also participated in the experiment with his newborn second and third sons.

She said, "Ever since I was pregnant with her second son, I bought a device to take an electrocardiogram of my baby and practiced how to use it. I don't think I could have figured it out."

It is important to be "carried" to stop crying

This image shows an experiment that Mr. Kuroda and his third son did.

At first, the third son cried, but as Mr. Kuroda continued to hold him, he gradually stopped crying.

Dr. Kuroda's experiments showed that the two actions that were effective in stopping the baby from crying were

▽"holding and walking" and

▽"moving in a stroller".

On the other hand

, almost no effect was seen in the two actions of ▽ "

sitting and sitting" and ▽ "laying on the bed".

As a result of the experiment, Mr. Kuroda strengthened his conviction that "carrying" was effective in stopping the baby from crying.

However, even if he stops crying, another wall of "putting him to sleep" stands in his way.

How can a baby who has stopped crying go to sleep smoothly?

The trick to putting him to sleep is “walking around in your arms for 5 minutes without thinking about anything else”

Therefore, Mr. Kuroda further verified how long it would be necessary to continue the "cuddle walk", which was the most effective, to make the baby fall asleep.

We looked more closely at 11 babies in the previous experiment who were crying violently.

All 11 babies stopped crying and 5 of them fell asleep when each mother held them for 5 minutes.

In the paper announcing the results of the experiment, Dr. Kuroda summarizes the data for babies up to 7 months old, but in reality, experiments have been conducted with slightly older babies, and the results can be expected.

On the other hand, she said she doesn't want babies under a month old, who couldn't get accurate data in the experiment, or babies who are worried about their health.

On top of that, he advises that the important trick is to keep walking without thinking about anything else.

“The best thing to do is walk empty-handed so that the baby can fall asleep naturally. It is also important not to look at it, as it will be distracting if you look at it.As for how to hold the baby, make sure that the baby's stomach, chest, and head are close to the body so that the head does not wobble.5 to 10 If I can't stop crying after parting, I hope I'm in the mood to see if there's anything out of the ordinary, I wish I knew this trick when I started raising my first child. But".

There is still a "back switch phenomenon" The research does not end here

Nonetheless, many people must have experienced the phenomenon of a baby waking up and crying the moment they put him or her in bed thinking, "I think it's time to go to sleep...".

This phenomenon is also called "back switch".

It's like having a switch on your back, and when the switch is turned on, you have to start over from step 1.

Even in this experiment, about one-third of the sleeping babies woke up when they were put to bed.

The research does not end here.

Kuroda and his colleagues investigated the difference between the babies who woke up and the babies who didn't wake up.

Babies who woke up slept an average of 3 minutes before being put to bed, while babies who stayed asleep slept an average of 8 minutes.

In addition, among the babies who continued to sleep, it was confirmed that babies who slept for less than 5 minutes before being put to bed seemed to wake up, such as opening their eyes on the way.

They found that how long they slept before being put to bed affected their success in getting them to sleep.

Mr. Kuroda believes that after the baby has fallen asleep while holding the baby, if you continue to hold the baby for 5 to 8 minutes before putting it to bed, it will be harder to wake up.

"If your baby falls asleep after 5 minutes of 'cuddle walking', please resist the urge to put him to bed immediately. Before putting him to bed, sit on a chair or bed for 5 to 8 minutes. Wait, and your baby will enter a deeper phase of sleep, so if you put him to sleep and wake up a little, he's more likely to fall back asleep."

"Back switch" The point was not the back!

In addition, Mr. Kuroda used an electrocardiogram to measure the heart rate when the baby was laid on the bed, and analyzed the state of tension and excitement.

And she tried putting the baby down on the bed gently and quickly, at different speeds, and making it harder to wake up by making the first part of the body that touches the bed the head first and the bottom first. I searched for a way to sleep.

As a result, there was no difference in how to lay down, but there was an unexpected discovery.

It wasn't when the back touched the bed that the baby's heart rate increased to make it easier to wake up, but when the baby's tummy started to move away from the parent earlier.

It is said that babies are always sensitive to subtle changes in their parents' behavior even when they appear to be sleeping.

Since primate babies are always clinging to their parents' bodies, Kuroda believes that when human babies are separated from their parents, they feel the danger of falling and wake up.

The “conventional theory” of the “back switch” has been overturned, and science has also clarified how to sleep without waking the baby.

"Scientific research into the 'back switch' suggests that the switch is actually in the stomach, which is in contact with the parent, and that the baby has a 'separation sensor.' In order to prevent this 'separation sensor' from working, it is recommended that instead of lowering it by hand, it is recommended that you lower your body slowly while keeping your stomach in close contact."

It may be effective even for mothers, fathers, and people who are not blood related!

?

This experiment was conducted by the mother, but Mr. Kuroda believes that fathers, grandparents, and unrelated people will have the same effect, and is continuing research to verify the effect.

Although the final results have not yet been released, there is data that shows that even people other than mothers are sufficiently effective for babies before they become shy, so Mr. Kuroda said, ``I would definitely like fathers to try it. , I want you to confirm the effect."

A scientific review of the “tricks” of putting them to sleep

I would like to reconfirm the "tips for putting a crying baby to sleep" derived from Mr. Kuroda's research.

[1] At the same pace, 5 minutes of “cuddle walking”.

[2] Even if you think you've fallen asleep, you can sit down and continue holding for 5 to 8 minutes.

[3] When laying on the bed, slowly lower your body while keeping your stomach in close contact.

A future where science makes parenting fun

Mr. Kuroda is aiming to develop an application that supports childcare, so that these research results can be used.

The idea is to measure the baby's heartbeat with a smartwatch or other device, predict the state of sleep at that time, and advise parents on the best actions to put them to sleep.

Mr. Kuroda envisions a future in which new scientific technologies will make parenting fun.

"I think that there are times when childcare is frustrating because there is no clear way to deal with 'night crying', but if we apply technology, we will be able to more acutely know the condition of a baby who cannot speak. I want to find more ways to support child-rearing with science and make child-rearing fun.”