A portion of a new father’s brain changes size and shape, giving him a more refined sense of empathy, according to early results from a new scientific study.
Scientists at the University of Southern California (USC) studying neuroplasticity - which is the ability of our brains and nervous systems to rewire themselves when learning new skills - found changes in the default mode network, an area of the brain that lights up when we are being empathetic.
It has been known that the brains of new mothers change to cope with a newborn, but it is the first study to suggest that the changes are occuring in the brains of new fathers too.
"Becoming a parent entails changes to your lifestyle and your biology,” Professor Darby Saxbe, of USC and senior author of the study, explained.
"And it requires new skills like being able to empathise with a non-verbal infant, so it makes sense. But it has not [previously] been proven that the brain would be particularly plastic during the transition to parenthood as well."
The study, published in the journal Cerebral Cortex examined brain scans from 40 expectant fathers - 20 in the US and 20 in Spain. A group of 17 childless fathers were also scanned in Spain for comparison.
For the Spanish fathers, researchers scanned their brains before their partners became pregnant and then again two to three months after their partners gave birth. The childless men also underwent scans at similar intervals.
For the men in the US, researchers scanned their brains when their partners were in their third trimester (around 30 weeks pregnant).
They scanned the fathers' brains again seven to nine months after the birth.
The scientists found that the most significant changes in the new fathers occurred in the cortex: the brain's outer layer which is involved with attention, planning and executive functioning.
The study showed changes in the portions of the cortex that affect processing visual information after the babies were born.
Changes in mothers
Previous studies of mothers have revealed changes in cortical areas that are key for the default mode network. New mothers also presented changes in their subcortical areas (below the surface of the cortex). These areas are linked with emotion, threat and reward processing in mothers.
Prof Saxbe said: "It might suggest that more, higher-order processing is involved in fatherhood specifically, whereas mothers show changes at a more basic mammalian level.
"In any case, the fact that we have found changes in the cortex both for fathers and mothers suggests that there is some remodelling of the social brain taking place."
Further research is planned to discover why the change happens. Prof Saxbe’s team plan to look into the individual differences in the changes associated with hormones and parenting inside a new father’s brain.
“It may be that visual cues are particularly important for orienting to offspring and understanding their needs, given that infants are non-verbal,” Prof Saxbe said, “It’s too soon to speculate with such a small sample.”
