In particular, the before and after anatomical magnetic resonance imaging on women pre- and post-pregnancy, compared to women who had never been pregnant and men. This research discovered a dramatic difference in the volume of gray matter in post-natal female brains, particularly in the organ's social regions.
Jodi Pawluski, a researcher at University of Rennes 1 in France, was surprised at how much women's brains actually transform after having children. Motherhood is one of the most significant biological events a woman has in her life.
Some effects of those brain changes may moderate over time, but other effects linger, shaping the mother’s brain well past their child-rearing years and even influencing her relationships with future grandchildren. Researchers found no change in gray matter makeup for fathers, indicating that women experience an entirely unique biological change when they become mothers.
Elseline Hoekzema, who studies pregnancy and the brain at Leiden University in the Netherlands, found the results surprising. "I’ve never seen anything like this in any of the data sets I've worked with… I hadn't expected such remarkably robust findings and this degree of differentiation."