Brain Area Plays Role
Bonding Mother and Baby

An area of a woman's brain associated with emotion processing seems to play an important role in establishing the bond between a mother and her baby, says a University of Wisconsin-Madison study.

The researchers explored this connection in six mothers and their babies. The researchers took up to 150 photographs of each baby when they were between the ages of 3 months to 5 months. About six weeks later, the mothers returned to the lab. None of the mothers suffered from postpartum depression.

The mothers were shown photos of the happy faces of their babies, other people's babies, adult acquaintances, and adult strangers. While the women viewed the photos, they were given a series of functional magnetic resonance imaging (fMRI) brain scans that showed activity in the mothers' brains.

At the same time, the mothers rated their moods on a nine-point scale based on five feelings: happy, warm, loving, motherly, and excited.

When they saw photos of their own babies, compared to seeing a photo of someone else's baby or no photo at all, the mothers showed increased activity in the orbitofrontal cortex. That's a brain region in the lower part of the frontal lobe that's involved in decoding the emotional value of a stimulus.

This increased orbitofrontal cortex activity was equally strong in both brain hemispheres.

The study also found the mothers' mood ratings corresponded to brain activity changes. For example, the happier a mother said she was, the more activity she had in both orbitofrontal areas.

This link between mood and brain activity confirms that the orbitofrontal cortex is involved in emotion processing, and also suggests it may play a role in the bonding between a mother and her baby, the researchers say.

The study appeared in a recent issue of NeuroImage.