A smile a mom will love

An image of a smiling baby activates the reward centres of its mother’s brain—sounds like common sense. But research into how a mother reacts to the looks on her baby’s face, published this week in the journal Pediatrics, has important implications for understanding how mothers and babies bond, which can help in cases where the mother-baby relationship doesn’t develop as it should.

Researchers from Baylor College of Medicine in Houston, Tex. wanted to find out more about the effects of different factors in child development, and made use of a magnetic resonance imaging (MRI) machine to scan the moms’ brains as they looked at photos of their own baby as well as unknown babies.

The scientists recruited 28 pregnant women in their final trimester, who remained in the study for a year and a half. Several months after birth, the research team videotaped the babies to get pictures of their faces in different stages of emotion, including smiling, crying and neutral. These images were shown to the mothers while they were being scanned in the MRI machine to look at how their brains responded when they saw pictures of their own baby compared with a baby they’d never seen before.

The researchers were particularly interested in parts of the women’s brain involved in reward processing, and associated with the neurotransmitter dopamine. They found that it was just the smiling faces where there was a difference in activation in these dopamine-reward processing areas of the brain. When the mothers saw their own baby smiling, these regions were strongly activated in comparison to the unknown baby face. Understanding this connection could help to reinforce and establish care-giving behaviours in the mother.

Caring for an infant can be tedious and frustrating, but if the mother is rewarded, it becomes worthwhile. And what happens in the first couple of years sets down lifelong relationship patterns.

Do you see your baby’s smile as the sweetest of them all?