Keenan: Fatherhood changes the male brain

Recent research showed that pregnancy leads to “selective and robust changes in neural architecture and neural network organization.” In other words, it remodels the brain of a woman to help her understand and respond to cues coming from her infant.

Scientists lost no time popping new fathers into their MRI machines. They found that we, too, undergo baby-related brain changes, even though we don’t have the same surging hormones as our mates.

A group led by psychology professor Darby Saxbe of the University of Southern California scanned 20 first-time fathers during the third trimester of their partners’ pregnancies and again seven to nine
months after the birth. A similar group was analyzed at a Spanish hospital.

In a journal article, Saxbe writes that their study is “the first to identify structural brain changes in first-time fathers that mostly affect cortical circuits, involved in social understanding, and not subcortical circuits, associated with reward processing and motivational approach.”

Luckily for us, these authors also explain their findings in The Conversation (theconversation.com), an excellent site that combines “academic rigour and journalistic flair.” In that article, they report that “fathers’ brain changes appeared in regions of the cortex that contribute to visual processing, attention and empathy toward the baby.” Overall, they found brain changes in fathers were almost half those seen in mothers, who, after all, experience pregnancy on a more visceral level.

It’s already well known that males usually experience lower testosterone levels when they become fathers. Northwestern University anthropologist Lee Gettler studied 600 Filipino men and found that
“Men who became partnered fathers then experienced large declines in waking (median: -26%) and evening (median -34%)” testosterone levels. Gettler found this result was more pronounced in men who reported participating in childcare for three hours or more per day.

The MRI studies also demonstrated the impact of participation in child rearing on brain changes in new dads. Saxbe notes that “Spanish fathers, who, on average, have more generous paternity leaves than
fathers have in the U.S., displayed more pronounced changes in brain regions that support goal-directed attention, which may help fathers attune to their infants’ cues, compared with Californian fathers.”

Another study found that homosexual male fathers who were primary caregivers also showed strong connections in parenting brain regions when they viewed their infants. Of course, our understanding of just what constitutes a parenting region is still evolving, which is why these studies are so helpful.

It should be obvious that our brains can change. How else could we learn to speak a new language or play a musical instrument? They open up the whole world of neuroplasticity, which is the subject of
countless self-help books of the “rewire your brain” variety, as well as weighty academic tomes.

One of those academic books, Neuroplasticity by British author and trained neuroscientist Moheb Costandi, notes that “among the general public, the concept is generally misunderstood, and misconceptions about what neuroplasticity is, and is capable of, are rife.”

Costandi traces the origins of the concept back to the early 1780s, when Italian anatomist Michele Vincenzo Malcarne trained birds and dogs to do various tasks, then examined their brains, looking for
changes. Modern technology like fMRI (functional magnetic resonance imagery) means that we don’t have to cut open the skull to do this kind of investigation.

Neuroscientific evidence is even finding its way into the courtroom. In a 2009 case in Illinois, defence attorneys for confessed child killer Brian Dugan introduced fMRI scans at his sentencing hearing.
They argued the evidence showed that his brain was so abnormal that it put him in the 99.5th percentile for psychopathy. The jury still sentenced him to death, but that became moot in 2011 when the state abolished capital punishment.

It’s important to note that fMRI evidence in court is still controversial. However, U.S. judges typically allow even “out there” evidence in cases that might involve the death penalty.

On the flip side, changes in the brain might someday rat us out. Actor Alan Alda, who I’ve had the privilege of meeting, and who is one of my science communication heroes, did an experiment for a PBS documentary called “Brains on Trial with Alan Alda” He was told to steal an object (either a ring or a watch) without telling the researchers what it was. Sure enough, in the fMRI, his brain activity disclosed the theft.

While Orwellian fMRI lie detectors are not here yet, experts like Penn State bioethics professor Jonathan H. Marks have accused the U.S. government of applying the technology to screen suspected terrorists. For example, showing them a terrorist training camp that they have visited might produce involuntary brain activity that they recognize the setting.

Luckily, the worst interrogation most new fathers are likely to face involves forgetting to buy diapers or baby wipes. The good news is that their brains have probably changed to be more attentive to baby’s
needs.

Dr. Tom Keenan is an award-winning journalist, public speaker, professor in the School of Architecture, Planning and Landscape at the University of Calgary, and author of the bestselling book, Technocreep: The Surrender of Privacy and the Capitalization of Intimacy.