14 DAY TRIAL // New mothers tend to experience a gray matter boost in the months following the delivery of their baby or babies, even if that time is generally considered to be very stressful.
Certain regions of their brains grow in size, researchers have demonstrated in a new study. In other words, women are not “losing their minds” when dealing with a baby.
The team behind the new work also showed that moms who are most excited about having a baby tend to show the largest amount of gray matter growth. The effect targets very precise areas of the brain.
Cortical regions that play critical roles in motivation, reward and the regulation of emotion are the most affected, the team goes on to say. The group was led by developmental psychologist Pilyoung Kim.
For the new investigation, new moms were asked to come in for a Magnetic Resonance Imaging (MRI) scan a couple of weeks after they had given birth. They were called again several months later.
Kim, who now holds an appointment at the National Institute of Mental Health (NIMH), investigated 19 women, and found increases in gray matter amounts in those specific areas in all of them.
Areas found in previous studies to control sensory perception, reasoning and judgment were also found to be slightly larger in all of the test subjects, LiveScience reports.
The team believes that the infants have something to do with these modifications because it is relatively uncommon for such gray matter boosts to develop in the adult brain.
“Whether this is affecting mothers' behaviors or are mothers' behaviors affecting the brain? It's not clear,” Kim says. In the animal kingdom, hormones associated with motherhood change the anatomy of the brain as well.
These hormones include prolactin, estrogen and oxytocin, and all of these chemicals exist in the human body as well. However, it is very difficult to determine their exact influence on women's brains.
Kim explains that all of the regions affected by the changes played a direct role in either maternal behavior, or in the higher cognitive functions usually associated with parenting.
Areas that grow after babies are born include the prefrontal cortex, the parietal lobe, as well as some regions located in the middle of the brain, such as the hypothalamus, the amygdala and the substantia nigra.
The researchers say that they now want to replicate this study on a larger number of women, to see if the correlation holds true. Their work is published in the October issue of the journal Behavioral Neuroscience.