Baby’s smile: drug-like high for mothers

SYDNEY: Seeing her own baby smile can give a mother a natural, drug-like high, according to new research.

Scientists at the Baylor College of Medicine in Texas, U.S., have found that key reward areas of mothers' brains were activated by the sight of their own babies smiling. The regions affected include areas involved in emotion processing, cognition and behavioural outputs – areas that have also been associated with drug addiction.

Critical bond

"The relationship between mothers and infants is critical for child development," said lead author and paediatrician, Lane Strathearn. He said the findings, reported in the journal Pediatrics, help to explain the neural basis of how mother-child bonding works.

The response that babies get when they smile or cry has an important impact on their development. Strathearn said that while experts already knew that the reward system of a baby's caregiver could be activated by these cues, but they didn't know if seeing someone else's baby would cause a different response.

Scientists scanned the brains of mothers with a functional magnetic resonance imager (fMRI) while they looked at smiling, crying and neutral pictures of both their own baby and an unrelated baby. fMRI measures blood flow to different regions of the brain, indicating which are getting the most use.

Seeing their own baby smiling produced significantly stronger responses in the mothers' brains, than seeing another baby smiling, said the authors. Seeing their own baby smile also activated reward areas of the brains that are stimulated by drug-taking such as some frontal lobe regions, the substantia nigra regions, and the striatum.

Drug-like high

The activation of so many reward areas of the brain could be why mothers are motivated to continue interacting with their smiling baby, Strathearn said.

Romina Palermo, a cognitive psychologist at Macquarie University in Sydney, Australia, agreed that these parts of the brain might be important in mother-infant bonding "[But] you would have to…see whether mothers who showed poor attachment to their infants showed reduced activation in these same brain areas," she said.

Like Strathearn, Palermo believes that studies like this may one day help parents who have poor attachment to their babies. In the meantime, it explains why seeing your own baby smile is a uniquely pleasurable experience.