LOS ANGELES — Becoming a new father can spark feelings of joy, but these emotions may also come with some permanent changes to the brain. A recent study looking at “dad brain” found that first-time fathers show signs of brain shrinkage, especially in areas involved in empathy and visual processing.
The study authors suggest that brain changes come from neuroplasticity, the ability to create or modify brain connections to adapt to new experiences.
“Becoming a parent entails changes to your lifestyle and your biology,” says Darby Saxbe, a professor of psychology at USC Dornsife College of Letters, Arts and Sciences and senior study author, in a news release. “And it requires new skills like being able to empathize with a nonverbal infant, so it makes sense but has not been proven that the brain would be particularly plastic during the transition to parenthood as well.”
The team scanned the brains of 40 about-to-be fathers from the United States and Spain. As a control group, the researchers also performed brain scans on 17 men without children. Spanish researchers also scanned the brains of 20 men (average age being 35) before their partner became pregnant, and then once more two to three months after their partner gave birth. Childless men followed the same timeline to receive brain scans. For U.S. participants, expectant fathers underwent brain scans when their partner was in their third trimester and then again seven to nine months after birth.
The most significant neurological changes among all men took place in the cerebral cortex—an important area that regulates attention, planning, and executive function. When comparing brain scans of first-time fathers before and after the baby was born they found the most affected area occurred in those involved in processing visual information and part of the default mode network. This network is activated when someone is daydreaming, trying to recall a memory, or thinking about the future. According to the authors, the regions of the network are likely involved in empathy.
Previous research on the brains of mothers has shown changes in the brain as well. These findings showed changes to areas below the surface of the cortex that are associated with emotion, threat, and reward processing.
“It’s too soon to speculate with such a small sample but it might suggest that more, higher-order cognitive processing is involved in fatherhood specifically,” says Saxbe. “Whereas mothers are also showing change at the 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 remodeling of the social brain taking place.”
The study is published in Cerebral Cortex.