The Science of "Mom Brain"

The research behind a mom's favorite excuse.

Posted May 07, 2018

If you’re a mom, chances are you’ve heard of “mom brain." Maybe you’ve even blamed it for a lapse in judgment, a missed appointment, or a minor emotional breakdown at some point in your life. As the mother of a toddler and a newborn, “mom brain” feels like my new normal: I am forgetful, absent-minded, and apt to get incredibly emotional if I see so much as a Hallmark commercial that features a child within a few years of my son’s age. Watching movies that have anything to do with a child getting lost or hurt is out of the question, and any news footage of children suffering can send me into an emotional tailspin.

SpeedKingz/Shutterstock
Source: SpeedKingz/Shutterstock

Some people are just sensitive, and maybe this doesn’t sound like anything out of the ordinary. But for me, this kind of forgetfulness and extreme emotionality is out of character: I’m not a crier and have never been much moved by pictures of babies; I’m generally pretty on top of things; I never miss a deadline, I'm organized, and even tempered. Or that is, I was until my son was born three years ago. Since then, I have trouble remembering anything that I don’t write down, I experience mood swings, especially when my son is involved, and, what’s worse, that these behaviors have become commonplace, especially after I became pregnant again.

So what’s the deal? Is “mom brain” just an excuse we use when we're a mess, or does becoming a mother really affect our brains?

Well, I’m sure it’s true that I use “mom brain” as an excuse for my mistakes from time to time, but it’s also true that our brains are affected by having children, sometimes in long-lasting ways. In fact, recent research suggests that a woman’s brain actually does change after she gives birth for the first time, in ways that might promote caring for her child. Researchers from the Autonomous University of Barcelona scanned the brains of a group of women before and after they gave birth, and found changes in the structure of their brains that were long-lasting, remaining for at least two years. Importantly, these changes were particular to the parts of the brain that were most active when the women were looking at pictures of their babies. Although further research is necessary to nail down exactly what these changes mean and how they affect mothers’ behavior, the researchers think these changes might help women understand the needs and emotions of their babies, helping them to better prepare for motherhood (Hoekzema et al., 2016).

Such changes in the way our brains function as a result of becoming a parent don’t just affect new mothers: There is evidence that the brains of fathers are affected as well. In one study, researchers scanned the brains of first-time mothers and fathers while these new parents watched a video of themselves interacting with their babies. The researchers found increased activity in the amygdala — the part of the brain responsible for emotional processing — in both mothers and fathers who were their babies' primary caregivers. In fact, the more involved the fathers were in taking care of their infants, the more their amygdala activity looked like the mothers’. This suggests that there isn’t just something special about physically experiencing pregnancy and childbirth that changes how the brain responds to babies (although there are some changes that are mother-specific); the act of parenting itself can cause similar changes in fathers, or perhaps anyone who plays a large role in raising children (Abraham, Hendler, Shapira-Lichter, Kanat-Maymon, Zagoory-Sharon, & Feldman, 2014).

Researchers have long suggested that these changes are good ones: They promote sensitivity to a baby’s needs, making us more responsive parents. Unfortunately, these responses can also have some negative side effects, perhaps explaining why many new mothers feel overly emotional from time to time, especially when thinking about the well-being of their own children. In fact, our brains' responses to our own children can be quite intense; some researchers have compared it to how we experience romantic love (Bartels & Zeki, 2004).

There is also evidence supporting the idea that having a baby interferes with our memory, but not in the way you might think. Researchers speculate that oxytocin — a hormone present in mothers during labor, pregnancy, and nursing — might play a role in keeping women from developing bad memories about the experience (Heinrichs, Meinlschmidt, Wippich, Ehlert, & Hellhammer, 2004). In other words, moms might become most likely to forget the bad parts of pregnancy and parenthood in favor of the good. It’s nature’s way of stacking the deck so that we’ll forget the trials and tribulations of pregnancy and parenthood, making it more likely that we will turn around and do it all over again. 

The moral of the story? If you’re having “mom brain,” take heart in knowing that we’ve all been there, and there’s evidence from neuroscience that it’s not only normal, but may be beneficial. We can’t, of course, blame our brains completely — a big part of “mom brain” probably just comes with being overwhelmed by new and challenging responsibilities that invade the same space where our old responsibilities still reside. We may never return to our pre-mom brains, but our new brains — forgetfulness, emotionality and all — might end up helping us become good, responsive parents.

References

Abraham, E., Hendler, T., Shapira-Lichter, I., Kanat-Maymon, Y., Zagoory-Sharon, O., & Feldman, R. (2014). Father's brain is sensitive to childcare experiences. Proceedings of the National Academy of Sciences, 111, 9792-9797.

Bartels, A., & Zeki, S. (2004). The neural correlates of maternal and romantic love. Neuroimage, 21, 1155-1166.

Heinrichs, M., Meinlschmidt, G., Wippich, W., Ehlert, U., & Hellhammer, D. H. (2004). Selective amnesic effects of oxytocin on human memory. Physiology & Behavior, 83, 31-38.

Hoekzema, E., Barba-Müller, E., Pozzobon, C., Picado, M., Lucco, F., García-García, D., ... & Ballesteros, A. (2017). Pregnancy leads to long-lasting changes in human brain structure. Nature Neuroscience, 20, 287-296.

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