It’s no surprise that pregnancy and childbirth, nine months of great changes to a woman’s body, also change her brain. And they do, by making certain parts of it less. Fathers, we can assume, will not be affected. But no. There is evidence that their brains are shrinking, too. A paper published in Cerebral Cortex by Magdalena Martínez-García of the Gregorio Marañón Health Research Center in Madrid, and her colleagues, reveal the details.
Dr Martínez-García’s study followed a group of 40 expectant fathers, 20 from Spain and 20 from the United States, and also, as a control, 17 Spanish men who did not have children on the way. To measure changes in their brains the volunteers underwent two magnetic resonance imaging (MRI) scans about a year apart. In the case of new fathers, one of these viruses is before, and the other after the birth of the child.
Researchers used the scans to compare the volume and thickness of the cerebral cortex, the part of the brain responsible, among other things, for things like sensory perception, language and cognition, as well as that of the sub-cortex, a diverse collection of structures. such as the hippocampus (involved in long-term memory formation) and the amygdala (which processes fear). They confirmed that there is a small but consistent reduction in the size of the cortices of new fathers after the birth of their child.
This contraction is not, however, evenly distributed. The biggest reductions are in the area in the back of the cortex where information from the retina is processed and interpreted, and in the “default-mode” network, a part of the neural network that is divided between three cortical areas of it is different, which is associated with the weather. , thinking and thinking about self and others.
This pattern partially mimics the changes seen in the brains of first-time mothers. For example, a study published in Nature Neuroscience in 2017 by some of the same researchers found that the areas of their brain’s default network are also reduced. The differences in the brains of first-time fathers are smaller than those in mothers, and they are also more variable—and, presumably, happen in a different way. But different physiological methods can still reach the same evolutionary end.
The mamas and the papas
That conclusion is presumably the best parent. The authors of this previous paper also gave new mothers a questionnaire that asked how they felt about spending time with their children, whether they felt they understood their children’s signs, and whether they had any resentment towards them. They found that postpartum changes in brain volume predicted both how a mother felt toward her child and the absence or otherwise of hostility toward him.
A test of Spanish fathers in Dr Martínez-García’s new research, by measuring their brain activity while they looked at pictures of their own baby and other babies, found a similar effect. It showed that those with the greatest reduction in brain volume had the strongest MRI responses to images of their own child compared with images of others.
Determining exactly how pro-parental vascular changes occur in men is way beyond the current understanding of neuroscience. But it is interesting to note that, at least in the case of Homo sapiens, a rare example of a mammal in which fathers and mothers have taken care of the offspring, such behaviors that the parents after birth seem to have connection to both women.
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