Reframing “Mommy Brain”

Many new mothers experience “mommy brain” as a deficiency, but it may help strengthen the communication between a mother and her infant.


A new mother finally gets her fussy baby to sleep and steps into a relaxing hot shower — with her glasses on. At a family barbecue she can’t recall the name of a relative she rarely sees. It’s easy to laugh off such lapses as mommy brain, but there remains a cultural belief that pregnancy and child care impact a woman’s cognition and mental life, long after a baby is born.

Women have often chalked up these changes to hormones, fatigue and the intoxicating love for a new baby.

Hormones do affect cognition, and, as anyone who has ever done shift work or had jet lag knows, sleep deprivation saps our mental abilities.

And the current evidence in scientific literature suggests that pregnancy changes the brain on a physical, cellular level in ways that we are only beginning to understand.

However, there is no convincing scientific evidence that pregnancy causes an overall decline in cognitive performance or memory.

Instead, most experts believe that pregnant women’s brain changes are an example of neuroplasticity, the process in which the brain changes throughout life by reorganizing connections in response to the stimulation of new experiences, and neurogenesis, the process of growth that allows for new learning. A 2016 study in Nature Neuroscience found that even two years after pregnancy, women had gray matter brain changes in regions involved in social cognition or the ability to empathically understand what is going on in the mind of another person, to put yourself in their shoes.

It may be that some subtle aspects of memory are sacrificed to enhance other areas of cognition. A 2010 study in Psychoneuroendocrinology showed that pregnant women experienced some impairment in the ability to remember words, but did not show changes in other memory functions such as recognition or working memory. This means that these women might forget the name of a character in their favorite TV show, for example, but would have no trouble in the type of memory that involves learning, reasoning and comprehension.

One theory is that these changes may have an evolutionary benefit to strengthen the communication between a mother and her infant. They may improve a mother’s ability to help a child to first understand the outer world, and then learn how to make sense of internal sensations.