Men's brains rewire when they become fathers, according to research from the University of Denver published in the journal Social Neuroscience.

The scientists examined images for structural changes in 16 fathers' brains when the new babies were between 2 and 4 weeks old and again when they were 3 to 4 months old. They found that the mens' brains had greater volume in several areas that are involved with parental motivation.

They also found decreased volume in other parts of the brain.

"Compared with the earlier scans, MRI at 3 to 4 months postpartum showed growth in the hypothalamus, amygdala and other regions that regulate emotion, motivation and decision-making," wrote Scientific American's Esther Landhuis of the research. She said that lead author Pilyoung Kim, director of the Family and Child Neuroscience Lab at the University of Denver, told her that dads with more growth in those parts of the brain were not as likely to show signs of depression.

"These early father-infant interactions and emotional bonding become the basis of the father-infant attachment, which has a long-lasting impact on cognitive functions and social attachment for offspring," the study stated.

According to an article on the study in The Independent, "Men become better at multitasking, more empathic, and more forgetful as they help raise their young child."

Hazlitt.net reported that the findings for fathers were comparable to those seen in the brains of mothers. "Unlike mothers, however, fathers also showed a significant decrease in gray matter in various regions. They lost volume in the parts of the brain that make up what’s known as the 'default-mode network,' which light up when you aren’t focused on one specific task. It’s the network that, according to recent research, may be associated with daydreaming and introspection. The researchers can’t be sure what causes this decrease, but they suggest it could simply be a matter of shifting resources — there’s less need for mental meandering when you are, for example, intensely focused on making sure your newborn child doesn’t die."

Kim, an assistant professor, has also published research exploring poverty's impact on a mother's brain, how the birth of a child affects a mom's gray matter and other related topics. In an interview with Colorado Public Radio, Kim explained that "one of the reasons people have babies … is because they find the emotional connection with their babies so rewarding. But for mothers to feel that emotion, their brain has to undergo big changes. Studies show it actually grows and rewires, particularly in the regions known as the 'reward circuits.'"

The new study is a part of a growing body of work on what happens to the brains of new parents. A University of Wisconsin-Madison behavior study of soon-to-be fathers last year cited by Landhuis called a father's viewing of a midpregnancy ultrasound a "magical moment" in creating bonds between fathers and babies.

"Yet the emotional bond was different than it is in expectant moms. Instead of thinking about cuddling or feeding the baby, dads-to-be focused on the future: They imagined saving money for a college fund or walking down the aisle at their daughter's wedding," Landhuis wrote.

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