Your baby’s smile is a natural high…
Seeing your baby smile lights up the reward centers of your brain in a way similar to the high provided by recreational drugs, say Baylor College of Medicine researchers. The finding could help scientists figure out the special mother-infant bond and how it sometimes goes wrong, says Dr Lane Strathearn, assistant professor of pediatrics at BCM and Texas Children’s Hospital.
“The relationship between mothers and infants is critical for child development,” says Dr Strathearn. “For whatever reason, in some cases, that relationship doesn’t develop normally, with devastating effects on a child's development.” To study this relationship, Dr Strathearn and his colleagues asked 28 first-time mothers with infants aged 5 to 10 months to look at photos of their own babies and other infants while they were in a functional magnetic resonance imaging scanner (fMRI). The machine measures blood flow in the brain and in the scans, areas of increased blood flow light up, giving researchers a clue as to where brain activity takes place.
In some of the photos, babies were smiling or happy. In others they were sad, and in some they had neutral expressions. When the mothers saw their own babies’ faces, key areas of the brain associated with reward lit up during the scans. The areas stimulated by the sight of their own babies were those associated with emotion processing, cognition and motor/behavioral outputs. “These are areas that have been activated in other experiments associated with drug addiction,” says Dr Strathearn. “It may be that seeing your own baby’s smiling face is like a natural high.”
The strength of the reaction depended on the baby's facial expression, he said. “The strongest activation was with smiling faces. There was less effect from pictures of their babies with sad or neutral expressions.” Overall, the mothers responded much more strongly to their own babies’ faces than to those of an unknown baby.
“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,” says Dr Strathearn.
The study was published online July 1, in the journal
Pediatrics.