Motherhood Triggers Brain Growth

New moms are often famous for acting scatter brained and being forgetful. But these are not the only changes in the brain that come along with motherhood, according to a study published in the journal, Behavioral Neuroscience. The study shows that motherhood triggers changes in those areas of the brain that result in warm and efficient parental behavior.

“Motherhood resulted in the growth in those areas of the brain that are involved in maternal motivation and reward processing," says Pilyoung Kim, PhD, a developmental psychologist and post-doctoral researcher at the National Institute of Mental Health. In this study, researchers took magnetic resonance imaging (MRI) of the brain of 19 new moms who delivered at Yale-New Haven Hospital. The first MRI was performed two to four weeks after delivery. The second MRI was taken in the participants after three to four months. “Imaging showed the differences in the volume of brain matter," says Kim.

Participants reported their perceptions about parenting and the child, for which they chose a word from those given like beautiful, ideal, perfect, and special for babies, and blessed, proud, and content for parents. Imaging showed a change in the areas of the brain that were involved in maternal motivation, emotion and reward processing, sensory integration, reasoning, and judgment. “Growth in the areas of the brain may be responsible for the interaction, supervision, and planning of parental behavior and engaging in a warm relationship with the baby," says Kim.

Mothers who had more growth in the gray matter in these regions were more likely to rate the babies in a more positive way, including ‘special’ and ‘perfect’.  According to Kim, the study only mentions the association between changes in the brain and motherhood. He speculates that as the brain undergoes changes, they focus more on taking care of the baby and forms emotional bonding with the child, despite having very stressful times in the beginning of motherhood.

“Many mothers report that they do not remember things well after delivery. Some studies show that this condition may improve with time," says Kim. According to Kim, it is difficult to quantify the changes in the brain, but it is clear that these small changes are significant.

Craig H. Kinsley, PhD, professor of neuroscience at the University of Richmond in Virginia, commented that this study translated the studies in animals into meaningful human connections. According to him, the growth of brain in new moms is not surprising. “Many earlier studies have shown that the brains of new moms are considerably different from the brains of women who were not mothers," he adds. Recent studies have changed the general belief that maternal brain is instinctual. Moreover, the interaction between the mother and the child is not unilateral, but bilateral as there are a number of stimuli from the child back to the mother.

According to Kinsley, these simulations may cause the mother’s brain to respond in a way that is reported in this study. “The brain and behavior changes may be caused by a combination of hormones and stimuli from the infant," he says.

Kinsley agrees that the present study has shown a correlation between birth of a child and maternal brain and not the cause and effect relationship. He feels that the correlation stems from the hormonal changes in the mother during pregnancy and the responses added by the stimuli from the baby. “But in general, the findings of the study might help to understand what goes wrong in the brain of a new mom who is indifferent or abusive," say Kim and Kinsley.