Whenever a woman becomes pregnant, it is inevitable that at some stage she, or someone else, will comment on her newly developing so-called ‘baby brain’ or ‘mummy brain.’
Characterised by brain fog, trouble focusing and remembering certain things, it has for decades been used as an apology by mothers (“so sorry I left the keys in the front door”) and as a way to dismiss a woman’s intellect and ability to function at work.
Yet researchers are now challenging the narrative that the mummy brain is a negative stage of a woman’s life, and should instead be looked at as an adaptive “pruning” rather than a dulling of cognitive function.
Dr Clare McCormack, an Australian research assistant professor based at the at NYU Langone Health, has been studying the mummy brain for years.
She’s come to realise that the key to deciphering how we research the process of becoming a mother – also called matrescence – has been to look to similar studies in animals.
“In the animal world, the questions we ask tend to be driven by understanding behaviour that seemingly comes out of nowhere.”
“How does this animal suddenly know how to be a parent? In non-human literature, the focus is often on positive adaptations of parenthood, and looking at how this shift in cognition and behaviour affects neuroplasticity.”
Yet when it comes to humans, the perception that women’s brains turn to mush during and after pregnancy shape the questions and tests that scientists use to measure these changes.
“In human studies, science has been set up to find a deficit,” she says. “This means that research questions go looking for the deficit, and as such set up specific memory tests comparing new mothers with non-mothers in a lab setting that usually benefits the non-mothers.”
McCormack’s research, recently published in JAMA Neurology, asks us to consider the validity of testing pregnant and new mothers’ memories by using tests that look at subjects and items less relevant to these women’s life experience, instead of more “ecologically relevant” stimuli and tasks.
“We developed a memory test that was using items that are actually relevant to your environment. In this case, it was a mixture of items related to parenting, such as images and words about parenting and baby-related things,” she explains.
The results were far from negative: they showed that not only did pregnant women experience a boost in learning when it came to remembering those items, but they performed better than non-parents in long-term memory tests.
“This makes evolutionary sense: even if one area of memory is temporarily slightly affected, it’s more about an adaptation to this period rather than a problematic period of forgetfulness,” McCormack points out.
Her research is not about debunking the mummy brain myth: significant neurological and brain changes in pregnancy are well documented. A 2016 Nature study found that the grey matter (which plays a role in tasks such as hearing, seeing, processing memories and decision making) in the brains of women who have recently given birth, seemed to be reduced in certain areas, and that those changes lasted for up to two years after birth.
As University of Melbourne Associate professor Olivia Carter explains, the study is unique in that it collected the brain scans from women and their partners prior to the woman falling pregnant with the couple’s first child, before re-scanning them a few months after the birth. These brain images were then compared to women and men of a similar age who did not have children during an equivalent time frame.
“The interesting and counterintuitive finding was that the brain reductions were not associated with any impairments in basic measures of cognitive function (such as working memory),” she writes. “Rather, the reduced brain volumes correlated with greater self-reported maternal attachment to their babies and increased brain activation associated with viewing their babies images.”
Another recent Australian study carried out by Dr Winnie Orchard and Associate Professor Sharna Jamadar from the Turner Institute for Brain and Mental Health at Monash University, found new mothers perform a little worse on memory tests than non-mothers only if they think they have a bad case of the mummy brain.
“We think that when you’re a mother, you tend to be more focussed on these periods of forgetfulness, not only because we have a social narrative about the baby brain but also because memory errors in the postpartum period also carry heavier consequences such as a sleepless night or, in extreme cases, harm to the baby,” Jamadar says.
And while they, like McCormack, do not deny the existence of the mummy brain, Jamadar believes it’s more to do with being overworked, tired and anxious rather than some structural deficit.
For McCormack, not only is this “misogynistic”, but thinking that pregnant women and new mums don’t have brains “capable of intellect” is also devaluing the role of a caregiver.
“Caregiving is very advanced and involves a lot of skills, which includes things that are valuable in the workplace,” she says. “Things like having empathy, being able to stay calm in the face of pressure, multitasking, regulating yourself and sensitivity are all part of the package”.
McCormack believes that we need to start looking at this period in a woman’s life as an area that’s wide open to investigation, just like we do adolescence. Having an open mind, rather than social and cultural influence guiding research in this area, is also important to understanding the mood disorders and anxiety that often accompanies pregnancy and the postnatal period.
“An unnecessarily high number of women don’t have an easy time during this period: as many as 1 in 5 will deal with postnatal depression, perinatal anxiety and mood disorders, which we know has a lasting impact on baby and mum,” she says.
“Unfortunately, due to a gap in research, the causes are not well understood, and we don’t have a clear picture of what successful adaptation looks like during this time.”
This includes understanding what a “well-adapted” brain looks like, and what the optimum level of cognitive change is, McCormack adds.
“If we don’t know what the optimal level is, we don’t know what maladaptive change looks like, which means we can’t predict who will develop PND.
“That’s just not good enough.”