Social Work Today E-Zine

The baby's smile that gladdens a mother's heart also lights up the reward centers of her brain, according to a Baylor College of Medicine (BCM) report that appeared in the journal Pediatrics.

The finding could help scientists figure out the special mother-infant bond and how it sometimes goes wrong, says Lane Strathearn, MBBS, an assistant professor of pediatrics at BCM and Texas Children's Hospital and a research associate in BCM's Human Neuroimaging Laboratory.

To study this relationship, Strathearn and his colleagues asked 28 first-time mothers with infants aged 5 to 10 months to watch photos of their own babies and other infants while they were in a functional magnetic resonance imaging scanner. In some of the photos, babies were smiling or happy. In others they were sad, and in some they had neutral expressions.

Researchers found that when the mothers saw their own infants' faces, key areas of the brain associated with reward lit up during the scans, signifying increased blood flow to that area. The areas stimulated by the sight of their own babies were those associated with the neurotransmitter dopamine. Specifically, the areas associated included the ventral tegmental area/substantia nigra regions, the striatum, and frontal lobe regions involved in emotion processing, cognition and motor/behavioral outputs.

"These are areas that have been activated in other experiments associated with drug addiction," says Strathearn. "It may be that seeing your own baby's smiling face is like a 'natural high.' Understanding how a mother responds uniquely to her own infant, when smiling or crying, may be the first step in understanding the neural basis of mother-infant attachment."

— Source: Baylor College of Medicine