TONTS. - Matrescence Festival with Dr Winnie Orchard

Episode Date: September 28, 2025

Welcome to forth episode of TONTS. Season 5 Matrescence Festival edition, join us as we look back through our Melbourne festival from March 2025.In this episode you will hear the first talk given by Dr Winnie Orchard, a cognitive neuroscientist, who specialises in understanding how pregnancy and caregiving reshape the brain and mind, she is leading efforts to create a standardized measure for recording and reporting reproductive health history across the lifespan.Winnie earned her PhD in Neuroscience from Monash University and completed a postdoctoral fellowship at Yale University, where she studied maternal brain function and cognition. Her research has been featured in journals such as Trends in Cognitive Science and Nature, and media outlets like TIME Magazine and New Scientist.Beyond her research, she is a passionate science communicator who believes that scientific discovery should be accessible to all.For more from Claire you can head to: https://www.clairetonti.com/ or her instagram @clairetontiFor more from Lizzy you can head to: https://www.lizzyhumber.com/ or her instagram @lizzyhumberAnd to keep up to date with past and upcoming Matrescence festivals you can follow @matrescencefestival on instagram or go to https://www.matrescencefestival.co.ukOriginal theme music: Free by Claire TontiEditing: Maisie JGSocial Media: Surabhi Pradhan Hosted on Acast. See acast.com/privacy for more information.

I would like to acknowledge the traditional owners of the land on which I create, speak and write today. There are Wondry people of the Kulin Nation and pay my respect to their elders past, present and merging, acknowledging that the sovereignty of this land has never been seeded. I want to acknowledge the people who have given birth on this land, raised children on this land for generations connected to country and spirit. Hello, welcome back to a special edition of Tontz. I'm Claire Tonti. And I'm Lizzie Humber and we are the co-founders of Matrescent's Festival. Listen along with us as we share live episodes from the festival in Australia that took place

across two days in March 2025. Today I'm going to introduce you to a very special human being. Her name is Dr. Winnie Orchard. She is a cognitive neuroscientist, specialising in how pregnancy and care giving shape our brains and minds across the lifespan. With a PhD from Monash University and post-doctoral work at Yale, her groundbreaking research has been featured in Time Magazine, Nature and Trends in Cognitive Science. Her work extends beyond motherhood, exploring how female biology, hormone changes and societal expectations influence brain function across all stages of life. As a passionate science

communicator, Dr. Orchard is committed to making scientific discoveries accessible to everyone. Oh my God. She absolutely does that in this talk. It's totally world-changing when you hear about the research that's being done and how much is still not known about women's brains, particularly mother's brains. Winnie speaks about how there's been more research into the effects of juggling on the brain than there has motherhood. It just goes to show where it is in the priority ladder of the patriarchal research system. I know. It's totally. Oh, my God. He's sad. clearly it just blew my mind my god when i interviewed her for the documentary and she said less than one percent of neuroscientists studied women's health overall like what so you think about how little is known about mother's brains it's mind-blowing what was the other thing there was something

else you love too one thing that she spoke about that really struck me was about memory because i don't know about you but my memory has been very hazy since having children and we talk about baby brain a lot And she says actually that memory is affected in the third trimester, but they've done studies into the effects of pregnancy on the brain and measured that against people who have never been pregnant. And actually there's no change. One year postpartum, there's no change in memory. But what they think is causing an effect is the cognitive load. The amount you have to remember is significantly increased. So if you have to remember 150 things rather than 100 things, of course you're going to forget some of them. So it was very validating, but also I was just so surprised that actually

my memory hasn't been affected. I just am needing to hold more, which goes back to sort of Melanie thinking about all those balls that you need to hold when you become a parent. So I'm really excited to share this first episode of Winnie. We're also in day two, which you'll get to hear in a future episode, Winnie's also going to be back talking about queer parenting and the research that's been done around that. So without further ado, over to Dr. Winnie Orchard. It's wonderful to be here and to be with you all talking about metrescence and talking about particularly the neuroscience of parenthood.

It's really close to my heart and it's nice to be able to share with you all what we've learned as well as hear different stories from different people's perspectives. It really makes it all richer for me. So I'm a cognitive neuroscientist and I study the way that the brain changes with pregnancy and parenthood. And today I'm going to tell you a little bit about. how the brain changes, both in terms of structure, so how it is physically, and in terms of function or how it behaves, as well as how these changes might relate to things like

cognition, so how our mind works, and this idea of baby brain, which you might have heard of. So I'll be talking about our current understanding of the maternal brain, including some of the research that I've done. As a general caveat, before I get started, I just want to clock that I'm focusing on research about birthing parents or gestational parents. And this is obviously just a subset of all of the parents and all of the different ways that we can come into motherhood and into parenthood. But unfortunately, it is where the majority of the literature is at the moment. This is the majority of the work that's been done. So it's what I can speak to with the greatest confidence.

However, tomorrow I will be giving a talk on queer parenthood and on non-birth. parents and what we do know about non-birthing parents in relation to brain structure and function. So come along tomorrow if you'd like to learn a little bit about that. It'll also cover things like gender identity, gendered norms, and it will include some research about fatherhood as well. Okay, so of those of you who are parents, how many of you think that your brain might have changed a little bit? yeah yeah so that's generally the response that we get when we talk about our research is that people are not generally too surprised that there might be some changes to the brain but what people are surprised is

about how little we actually know about those changes and how little research has been done to really characterize those changes and to give that information back to the real people so by the end of this talk I hope you understand four things and we'll touch on these four for things throughout. So the transition to parenthood is a neurodevelopmental life stage which involves adaptive changes to the brain. That pregnancy and the postpartum period

involve increased cognitive load and challenge and that while these cognitive challenges might not necessarily feel good, they might actually be good for our brains long term. So developmental life stage, adaptive brain changes, cognitive load and challenge and potentially good for our brain.

So what is a developmental life stage and what is it from a neuroscience perspective? So in neuroscience we can think about particular times across the lifespan where there's significant changes in brain structure or function and there's undergoing that restructuring. And we can call this neuroplasticity.

So the capacity of the brain to adapt to neuroplructure, environments and changing demands. And neuroplasticity is really essential for things like learning and memory and brain repair after brain damage. And throughout the lifespan, there's different periods where the brain has increased neuroplasticity. The brain is more plastic. It's more malleable, more easily changed. And these neuroplastic windows can represent both a vulnerability and a window of opportunity to change. And this idea that was brought up in the last session

about being made, not broken, is really important when we're thinking about sensitive windows of development. That if we're cracked open in this way and that's sort of represented neurobiologically, that is there is this window where you could go one way or the other. And so having that neurobiological basis

to understand that importance of extra care and support in this time, that there is a vulnerability there and that we need to be supported to have the best transition. So when we're thinking about developmental life stage and other developmental life stages across the lifespan,

we can really compare pregnancy and adolescents. And these parallels are pretty obvious and they're pretty compelling in terms of periods of extreme hormonal change. And indeed, the hormonal change, changes of pregnancy are more extreme in a shorter period of time. But beyond these biological changes, both periods involve really changing social roles. So in adolescence, we're shifting from being dependent on somebody to being independent and standing on our own two feet and taking

care of ourselves, whereas the transition to parenthood is really transitioning into having somebody depending on you and being there to be able to support another vulnerable human. So there's that biological similarity as well as a social similarity there, but we can also see that similarity represented in the brain. So the way that the maternal brain is changing across pregnancy and the early postpartum, it's actually very similar to the way that the brain is changing across adolescents. And indeed, there have been studies shown to literally compare women across the transition to parenthood and adolescents and to line those up and see

is the brain changing in a similar way? Is it changing in a different way? And indeed, it's very similar. So both transitions are changing what we call gyrophication, sulkle depth and sulkle length, which are not things that you necessarily need to know, but just that it's the way that the brain is folded and that those changes are,

shifting in both periods. So in this way we can think of the neuroplasticity and metrescence as really constituting this sensitive neurodevelopmental period where the brain is primed and is more ready to acquire that experience-dependent skill and knowledge. So being cracked open is letting you have more flexibility from those experiences. So while we do understand a fair amount about childhood, adolescence and even the aging process from this sort of developmental lens, motherhood is unfortunately somewhat of a missing time point

in our understanding of the lifespan and how our brains shift across the life. And most of the research to date has really shifted towards understanding the child or the impact of a maternal factor on a child outcome, be that a developmental outcome, a cognitive outcome, these sorts of things. So in contrast to these other developmental stages, parental neuroscience is really in its infancy.

So how many studies do we think are out there about how the brain is changing with pregnancy and parenthood? It's sort of thousands, zero, hundreds, tens, yeah. Yeah, we might be more surprised to learn that there's almost more studies looking at how juggling is changing the structure of the brain than there are studies looking at how pregnancy and parenthood changing the brain.

Yeah, and this is shifting. So this has been true, but we're on this wave now where more and more scientists are turning towards metrescence and our understanding this is a really key factor. And women's health in general is understudied. So of the roughly 50,000 neuroscience articles

published since the 90s, when neuroscience really had its moment, less than half of 1% of those studies focus on factors relating to women's health and women's bodies and this includes all of the research we know about the menstrual cycle, hormonal contraceptive use, menopause and pregnancy and parenthood. So 99.95% of the studies that we have

in terms of our brains and our brain health are excluding matters of women's health and that's really got to change. yeah thanks and it is changing and we're on that wave now so rest assured there's more more research to come but what do we know and that's really why I'm here today is to tell you what we do know not just what we don't know things and but yes indeed the brain is changing and it is changing in quite a significant way so much so that we could look at the brain scans of women who have had children two years ago and compare them to people who have not had children

and can say with 95% accuracy, whether that brain is from a mother or from a non-mother. So these results are quite striking. And we're seeing regions that are involved in the social brain that are changing. And many of these regions do experience both structural change as well as functional change across the transition to parenthood.

We see decreased grey matter in pregnancy, which then increases in the postpartum in this sort of U-shaped trajectories, goes down, and then it comes back up again. And usually that gets people a little bit like, oh, gosh, I'm losing some brain volume that maybe strikes a bit of concern. But in this context, we really think about

a decreased grey matter as a fine-tuning, as a more efficiency. And indeed, we see the same areas that are losing volume or losing cortical thickness as also being more active in response to videos or pictures of the child. So even though there's less, like structurally, it's doing more functionally.

So it's this idea of doing more with less, which we can really interpret as an increased efficiency of these networks. So other brain regions that are changing both structurally and functionally are brain regions, involved in reward circuitry, which really makes infants and children more rewarding, more engaging, we're more likely to spend time at attention, also heightening vigilance and threat detection,

looking in our surroundings, keeping our eyes out for things that are dangerous, and like I said, fine-tuning that social brain. So some of you might have heard of this idea of like theory of mind that might be familiar to some, how we make sense of the thoughts and feelings, emotions, needs of other people. How do we interpret that? And so the brain regions that are involved in theory of mind are undergoing massive restructuring through pregnancy and the postpartum. And indeed, these changes are quite adaptive.

You think about the tasks of early parenthood as interpreting and responding to non-verbal cues about what somebody needs, particularly in that pre-verbal stage when a child can't tell you what they need. You have to be able to infer that. And so that's really what's being supported there. But beyond that, the changes in the brain are also related to things like attachment,

maternal sensitivity, and more positive feelings about one's baby. And so the parents that are having more pronounced brain changes are a greater degree of these changes are having higher attachment, higher sensitivity. So that sort of leads us to think that these brain changes might be supporting the behaviours of early parenthood and they might actually be quite good. So, yeah, people don't necessarily know the way that their brain's going to change because, well, one, the science isn't there and that science is really only now being taken into sort of medical context into healthcare providers so that they can share with people

what's going to happen and what's going to change and what does that mean? Because I think a lot of people do experience changes to their brain. and minds and are a bit worried or concerned that maybe things are not normal or maybe it doesn't feel so good and so having this understanding that the brain is changing in this way and that those brain changes are supporting the acts of parenthood can be quite comforting. So changing tact a little to parental cognition. Who here is heard of baby brain? Yeah, yeah. So 80% of new mums will report some sort of cognitive decline in pregnancy and early parenthood.

It might be forgetfulness or brain fog or an inability to concentrate. And this is really portrayed quite heavily in media, in TV, in movies, and the way that we sort of talk about early parenthood. But you might be surprised again how little we actually know about these changes and what's normal and when we might return back to normal. how long these changes might last. So through pregnancy, we do know that there are some subtle decreases in memoryability, mostly in the third trimester, and mostly related to verbal memory.

So this ability to remember words, that tip of the tongue phenomenon, lists and things like shopping lists or whatever. But in the postpartum period, there's far less that we can say with certainty. Some studies show decreases still, some show no. differences, some show improvements. And so we set out to do a study looking at cognitive changes in parenthood.

We also did some MRIs on these new mums, but I'll tell you about the cognitive changes today. So we brought in a group of first-time mothers around one year postpartum. We also had a group of women who had never been pregnant. And we compared their brains

structurally and functionally, but also in terms of their cognition, to to see across a number of memory tests, how are they doing? Better, worse, or much the same. And so these two groups were matched in terms of age. They're the same age. They had roughly the same education. And we couldn't find any difference.

So our mothers and our non-mothers actually performed equally good across all of the tests. We had no significant results, which, I mean, now I'm not surprised, but at the time I was like, what? What we did find was that the mothers in our group self-reported worse memory. So even though they weren't performing worse, when we gave them a questionnaire that said rate your memory ability, they were rating their ability much lower than their non-mothers in our sample. We were a bit interested in why that might be.

And we looked into differences in depression, anxiety and sleep. And when we took depression, anxiety, and sleep into consideration, the difference in self-reported memory disappeared. So it seems that there might be something to do with wellbeing that means that mothers are self-reporting their memory worse, or this idea of negative bias, which we do see outside of the peripartum period as well. But just because we couldn't measure these differences doesn't mean that it's not there. People in their lived experience are saying, my memory.

different I've changed and we want to take that into consideration because certainly if 80% of new mums are saying something's changed then we can't discount that and it's important to look at so we are doing some research now and I'll speak more about this tomorrow it's a qualitative study to get new parents to explain in their own words what their changes are what are they experiencing to describe these changes in a richer way so that we can guide the research from new parents and what it is that they want us to focus on, particularly in terms of memory.

And one thing when we're thinking about memory in parenthood is this idea of cognitive load and just how much there is to remember and how much of that stuff that is there to remember is new. So maybe it's feeding schedules or nappies or just all of the different things that have to be remembered and attended to in a day, in a year, in a life. And with more things to remember, there are also more opportunities to forget. So if before you were a parent, you had a list of 10 things to remember and you remember all 10 of those things, you get 100%.

You nailed it. And then now you're a parent. You've got 20 things to remember. Maybe you're remembering 15 of those things. That's actually 150%. But it feels like 75%. And so having this idea of how the cognitive load is playing into our memories is actually really important when we're trying to objectively measure

how much somebody has on their mind. It's also important to consider from an evolutionary perspective why would new parents, who have just invested like a great deal of physical and genetic resources into creating this new human, why would they lose their mental ability? like it doesn't make a great deal of sense from an evolutionary perspective and indeed when we look at the animal literature from studies of rats and mice we see that motherhood actually increases learning in memory in rodents

so their brains are healthier they're more flexible they're more resilient to age-related decline and so very clear from the rodent literature that being a mother has long lifelong benefits and rats show permanent improvements in spatial learning in memory, in foraging and predatory behaviours, decreased anxiety, which is all thought to help them feed and protect their young. And indeed, older mother rats show decreased markers of Alzheimer's disease compared to virgin rats at the same age. So it suggests there might be something neuroprotective or beneficial for the aging process related to parenthood, even in rodents. So based on this literature, another series of studies that we've done is looking at

the structure and the function of the brain of mothers in middle and later life. So how long is the brain impacted? Does it sort of go back to normal? Does it stay impacted forever? And so indeed, through middle and later life, we see markers of brain change related to parenthood and related to how many children a person might have had. And these changes are broadly positive.

So across studies from our group as well as a number of other groups, mothers in middle and later life that have more children so larger families have younger looking brains both in terms of brain structure and in terms of brain function and this is broadly consistent across pretty much all of the research that has looked at this so it's really good news to some of you in the audience today so and I'll finish with this sort of idea of how do we marry these two literatures. How do we understand? Are we cognitively challenged in the peripartum period and then improved in later life? How does that make sense? How do those things go together? And a great question. So if we can think about early parenthood as a complex

and novel experience where there's all of these new changes, new tasks, new behaviours, so much learning that you have to do, and that learning is really going to sink or swim style. It's trial and error. There's no guidebook. There's no roadmap. You're learning on your feet. And as you learn something, as you master it, it's changing. And the child's developing and growing and has different needs. You can think about parenthood as brain training, as a caregiving as a dynamic learning experience that lasts for decades. And if we can think about it in that way, We know from studies of rats and mice, and indeed studies of humans, that more novelty, more complexity in an environment is good for our brains long term.

In rodents, we call this environmental enrichment. In humans, we call this cognitive reserve. It's one of the most important things in our later life is how much stimulation, how much physical stimulation, social stimulation, intellectual stimulation we have in later life. And parenthood might be one way that we get that increased novelty and complexity across our lifespan that leads to greater brain health in later life. So all of that to say, there is that age-old adage, once a mother, always a mother, and I hope you think that maybe that might be a good thing.

Wasn't that mind-blowing? I just, I could listen to when you talk about that all day. so fascinating. Thank you so much for being here. Thank you to Masey for editing this episode. You can find more from me at Claire Tanti on Instagram and at Lizzie Humber. You can find out more about Lizzie there. And then we also have our own Instagram handle at Matresson's Festival. All right. See you soon.