Carrying a baby elicits specific physiological and behavioral responses, research finds

Jun 21, 2013
Young mammal infants are calmed when carried—but not just held—by their mothers.

The bond between mother and child is the first and most important relationship for all mammals, including humans. Mammal infants are born with innate behaviors to seek closeness to their mothers and become distressed when separated from them, but the physiology underlying this response is largely unknown. Kumi Kuroda of the RIKEN Brain Science Institute and colleagues have now shown that being carried has a calming effect on infants, successfully identifying some of the brain mechanisms involved.

Kuroda and her colleagues recruited 12 healthy human infants aged between 1 and 6 months and recorded their heart rate, movement and crying while they were held or carried by their mothers. They cried and kicked more often when simply held by their mothers while seated and displayed an associated elevated heart rate. When carried by their mothers while walking, however, the infants became significantly calmer and adopted a characteristic posture in their mothers' arms.

The researchers found a similar calming response in mouse pups during maternal carrying. Like human infants, mouse pups also become still, cease their and show a decreased heart rate when carried.

Kuroda's team then either blocked the pups' sense of touch using a , abolished their sense of balance by surgical damage to the vestibular organ of the inner ear, or abolished their proprioception, or 'muscle sense', with a toxic overdose of vitamin B6. Only pups without a or proprioception failed to exhibit the calming response when carried, suggesting that the response depends upon these two senses rather than balance.

The researchers also found that mouse pups with that cause malformations of the cerebellum—a brain region involved in the control of movement—had abnormal postures during carrying, as did pups with surgical damage to the cerebellum. Finally, the team also showed that the calming response makes it easier for the pups to be carried.

"Infants with autism are reported to have difficulties adjusting their bodies to parental holding," says Kuroda. "Cerebellar abnormalities are among the most consistent neuropathological findings in autism, so we are now trying to test the hypothesis that children who develop autism may have atypical responses to maternal carrying."

"We would also like to identify the brain areas required for orchestrating the output components of the calming responses in the mouse model, and further investigate the human calming response to carrying," she adds.

Explore further: Deep sea fish eyesight similar to human vision

More information: Esposito, G., et al. Infant calming responses during maternal carrying in humans and mice, Current Biology 23, 739–745 (2013). www.cell.com/current-biology/r… ii/S0960982213003436

add to favorites email to friend print save as pdf

Related Stories

From mice to humans, comfort is being carried by mom

Apr 18, 2013

There is a very good reason mothers often carry their crying babies, pacing the floor, to help them calm down. New research published in the Cell Press journal Current Biology on April 18 shows that infants experience an aut ...

Brain research shows two parents may be better than one

May 01, 2013

A team of researchers at the University of Calgary's Hotchkiss Brain Institute (HBI) have discovered that adult brain cell production might be determined, in part, by the early parental environment. The study suggests that ...

Recommended for you

Dogs hear our words and how we say them

Nov 26, 2014

When people hear another person talking to them, they respond not only to what is being said—those consonants and vowels strung together into words and sentences—but also to other features of that speech—the ...

Amazonian shrimps: An underwater world still unknown

Nov 26, 2014

A study reveals how little we know about the Amazonian diversity. Aiming to resolve a scientific debate about the validity of two species of freshwater shrimp described in the first half of the last century, ...

Factors that drive sexual traits

Nov 26, 2014

Many male animals have multiple displays and behaviours to attract females; and often the larger or greater the better.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Strangetimez
not rated yet Jun 21, 2013
Should they not make the distinction between "parent" and "mother", since they did not mention any test with fathers? Sorry If I am biased. I am a single father who has raised my daughter since birth. To be completely honest, I see no connection or response a mother can illicit from a child that a father cannot other then breastfeeding. All these biased reports become amusing when youve raised a child on your own by yourself. I never expect to be perceived as equal, but that doesnt make it NOT true.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.