Why being carried soothes baby
18th April 2013 - Every parent discovers that their baby calms down and stops crying when picked up and carried, but the reason why has never been explained.
Now scientists in Japan have demonstrated the complex mechanism behind the phenomenon.
Carrying versus holding
Researchers from the RIKEN Brain Science Institute recruited 12 healthy infants aged one to six months and placed electrodes on their chests to monitor heart rate. The babies were then monitored while they were either lying in a cot, being held by their mother who was sitting in a chair or being held while the mother walked around a room.
In a series of experiments involving ECG [ electrocardiogram] measurements, the team found that the heart rates of babies greatly slow down immediately after they are picked up and carried. However, this is not the case if they are simply held.
Co-author Gianluca Esposito says in a presentation posted on YouTube: "Our data suggests that babies are more relaxed during carrying than holding, both behaviourally and physiologically."
A mother's touch
In experiments on baby mice, the researchers found that this calming response is dependent on the effects of touch and the ability to sense and understand body movement. They also report that the calming effect is processed in a region of the brain called the cerebellum.
They also say that this calming response to being transported by the mother may start in the womb, since between the 36th and 40th week of pregnancy, the foetus is more active when the mother is not moving about.
Preventing child abuse
The authors say their findings could have important implication for parenting and could even contribute to preventing child abuse.
"Such proper understanding of infants would reduce frustration of parents and be beneficial, because unsoothable crying is major risk factor for child abuse," says lead author Kumi Kuroda.
They say a brief period of carrying could also be an effective approach to soothe crying caused by irritations like vaccinations and frightening noises.
The research appears in the journal, Current Biology.