Study sheds light on parental instinct

By Michael Kahn

LONDON (Reuters) - The parental bond may be all in the mind, according to a study published on Wednesday that pinpoints a possible region of the brain key to an instinctive desire to care for and nurture infants.

This discovery helps answer the evolutionary question of why we view babies as special and could help doctors better identify people suffering from postnatal depression, the researchers at the University of Oxford said in the journal PLoS One.

"It is important because there has to be a reason why we look after our kids in general to make sure our species survives," said Morten Kringelbach, a neuroscientist, who co-led the study. "This is an idea that goes back to Darwin."

Kringelbach and his colleague Alan Stein showed how a region of the brain called the medial orbitofrontal cortex lights up to faces of infants but not to adults.

Scientists believe this area -- located just above the eyeballs and connected to the area important for recognizing faces -- is key to controlling emotions, Kringelbach said.

To do this, they used imaging scans to measure brain activity in volunteers asked to hit a button when a cross on a screen in front of them changed color. In between, images of unfamiliar infant and adult faces flashed on the screen.

There was no reaction to the adult faces but the infant images spurred a high level of activity in the brain within a second, an instinctive signal that may tell us babies are special, the researchers said.

"We think that the early response is guiding us to treat infants as special," Kringelbach said in a telephone interview. "It happens so fast that almost without a doubt there is no conscious control over that."