Our brains are mosaics, quilted together from pieces with varying hues.
January 2, 2018 1:48 PM   Subscribe

"The unfulfilled wish is, of course, that men’s brains differ from – and by the usual implications are superior to – those of women in just the same way as men’s physiques differ and are superior. Stronger body, stronger mind, as though the brain were not, at a minimum, a pack of neurons with a wide and varied cast of support cells but instead a mass of contractile tissue, easily built up and broken down simply by following the rules dictated in Men’s Health. And of course, the perceived binary of human anatomy offers thin scaffolding for the facile argument... Nature doesn’t do binaries nearly as often as people think. But she’s a whiz with mosaics."
posted by ChuraChura (19 comments total) 51 users marked this as a favorite

This whole piece is wonderful.
Currently, we have no way of looking at these brain regions to classify the organ as ‘male’ or ‘female’. But complexity intensifies when you add in the influence of steroid hormones. Like lemon juice acting on invisible ink, these signalling molecules can reveal the hidden capacities of neurons forming different brain regions. And just as no two brains will have the exact same neuron assemblage, no two brains will experience the exact same cocktail of sex steroid hormones. Indeed, no one brain will experience a consistent exposure to these hormones over the course of a lifetime or even over the course of two consecutive days. How could anyone paying attention ever argue that brains and the behaviours that they produce could be reduced to a simple choice of either this or that?
Thank you for sharing!
posted by fraula at 2:23 PM on January 2 [9 favorites]

Oh, I'm excited to read this one. And delighted to do so.
posted by sciatrix at 2:32 PM on January 2 [2 favorites]

Given that so much of the social messaging that children receive is relentlessly gender-based, perhaps autistic features aren’t manifestations of being masculinised. Rather, they are the result of an innate resistance to, or uninterest in, gender-based social demands of any kind. Indeed, autistic people are far more likely to view gender as largely a secondary consideration, and to express gender that varies from what was assigned them at birth.

In other words, at least some autistic people might well represent the mosaic brain as untouched by gender expectations and other social influences as a human brain can be. And they are on average far less likely than neurotypicals to consider gender as an important factor in … anything.

It's worth noting that there is a surprisingly large overlap between queer-identified and autistic people as well as between gender-variant and trans people and autistic people. I have often strongly suspected that this is a reason why, as a gender-variant autistic spectrum woman. Not the reason. But a reason.

The structural brain difference stuff is--fuck, I think many neuroscientists fail to comprehend the complexity of the human brain, or the sheer number of things that can modify and interact with brain function. To illustrate my point, let's talk about hormones, right? The author mentions them and casually says that perhaps hormone levels are the underlying factor for sex differences in brains, if they exist.

But hormones are like a loud crash ricocheting through a forest--steroid hormones, including sex hormones, literally slip through the walls of cells and blood vessels like a slender deer stepping through brush. They do not care where they go; it's one of the reasons that handling hormones skin to skin carelessly is a terrible idea. When bodies have to respond to them, then, you can't just say "ah, the hormones will go where they need to be because I will carry them through the bloodstream until they get there." No. If the hormones are like a crash in a forest, the body is like the whole forest ecosystem: some animals who hear the hormonal shift but do nothing, some animals who hear it and race into action to change their behavior, some who hear the shift and freeze in terror, and also things like plants and soil microorganisms and soft green moss that never 'hears' the presence of the hormone at all.

So if the body needs to take specific actions to the hormone, it needs to control first who hears the sound, and second what those tissues should do about it. And we know this is incredibly important in the brain, the most finely differentiated organ in the human body; hell, we know that something as simple as vasopressin receptor presence or absence in one part of a vole's brain will control whether that vole forms monogamous pair-bonds during sex, and receptor abundance in another part entirely will determine whether a prairie vole (which ordinarily would pair bond) will be tightly connected to his partner or whether he will range more widely and solicit attention from other adjoining lady voles.

These examples are static, determined by regulatory changes in the genes for the receptors, but not all receptor variation is like that. We know that receptor abundance is a plastic thing, too; it can be modified by circumstances in early growth, or receptor abundances can even be changed by shifts in the genes that are regulated--including those that code for receptor proteins--in a matter of hours. We know that the brain responds to stimuli in two ways with vastly different speeds: action potentials, which are quick but specific, and gene regulation shifts, which are slow. If we return to the metaphor of hormones as a loud crash, then, we can note that the brain can literally change who's listening to that bit of stimuli. And we know that different ecosystems and environments might have wildly different sensitivities to hormone influence, too.

But I almost never see any discussion about receptor variation in humans. Admittedly, it's hard to stain for--you need a brain divorced from its skull, really, and you'd have to hope that the receptors you're interested in are relatively static. That said, even if you can't directly study the variation in action, you have to understand how receptor distribution patterns might outright fuck over your conclusions about how hormonal variation actually contributes to variation among and within sexes.

And every damn time I talk to human-focused neuroscientists, particularly those who rely on fucking MRIs, it's like I'm talking total gibberish, like I'm some kind of space alien, when I bring these topics up. God help me if I try to initiate a discussion on variation, too, for neurobiologists who work on inbred strains of lab mice and rats purposely bred and raised to create the next best thing from clones out of science fiction. Not everyone, to be sure--there are absolutely NIH neuroscientists and plenty of people in lab mice and rats who know this. But an awful lot of the time.

There's this tremendous tendency to treat fMRI as the most sophisticated tool we have to understand the brain, but fMRI is not a magic bullet. It does not measure changes in "brain activity", in part because that's a meaningless term; it measures changes in blood flow to voxels of the brain that are averaged together, and the way people report that fMRI data is often misleading. Especially when you consider what the voxel size is and how painfully important it is to know precisely where you are measuring something in the brain from immunohistochemistry work.

Of course, all that rather exonerates structuralists, people who do MRIs to find out how the brain is shaped and how the patterns of anatomy change from person to person. But brain anatomy too is influenced by experience, and so people will make wildly ranging broad claims about the immutability of the anatomical differences while totally ignoring that the brain is literally the structure for which we have coined the term "use it or lose it" to refer to the structural connections among neurons that we can measure over time. It shouldn't be such a big deal to point this out, but it's remarkably hard to talk about in many circles, and I see an awful lot of science that totally fails to acknowledge any of this.

Brains are complicated. Biology is complicated. And the great truth of neurobiology is that anyone who has claimed to figure out how to classify brains perfectly and sort them into two neat piles--or three, or four, or eight--is missing vast swathes of the puzzle.
posted by sciatrix at 3:04 PM on January 2 [78 favorites]

and if you need me, I'll be in my angry dome!
posted by sciatrix at 3:05 PM on January 2 [29 favorites]

people in charge of grants HATE uncertainty and they are mesmerized by brightly colored animations, so dubious fMRI studies are here to stay, unfortunately.
posted by vogon_poet at 4:19 PM on January 2 [16 favorites]

Yep. And the more uncertain our funding climate, the more risk averse those reviewers get, and the more likely those pretty oversimplified fMRI studies are too stay.

Ugh. I can name like eight different techniques I think yield better and more informative data, but you mostly have to mock up your own infographics for those.
posted by sciatrix at 4:35 PM on January 2 [3 favorites]

The article is excellent and sciatrix' epic comment is better.
posted by evilmomlady at 4:37 PM on January 2 [3 favorites]

Wow, Emily Willingham is thoughtful and interesting. If her byline is on a piece, I know I'm going to find it worth reading. Thanks for posting this!

And, for the record, to hell with Simon Baron-Cohen and the bullshit that is the "extreme male brain" theory.
posted by Lexica at 4:46 PM on January 2 [7 favorites]

I thought the autistic bit near the end, about the dichotomy of perception of versus experience of, showed surprising and rare insight.

As a girlish boy married to a boyish girl, other parts of this piece really spoke to me, too.
posted by Construction Concern at 6:16 PM on January 2 [7 favorites]

I'm reminded by sciatrix's comment of one professor's snark on fMRI from my grad school days: "Trying to understand the brain using fMRI is like trying to understand what's going on inside a building by measuring what goes in and out of the plumbing."
posted by Making You Bored For Science at 7:27 PM on January 2 [8 favorites]

And every damn time I talk to human-focused neuroscientists, particularly those who rely on fucking MRIs

Please, the proper term is fucktional MRI
posted by Jpfed at 7:59 PM on January 2 [2 favorites]

But Nature made me. And I am not rare. Indeed, an entire category of girl and woman exists that is large enough to warrant the now-archaic category of tomboy. We are legion, and most of us likely wished fervently at some point that we could be boys so we could simply gain access to what interested us most.

I recently broke it off with a guy who was convinced I was rare and incredibly smart because was an old school computer geek that knew command line, among other things. One of the smartest people he’d ever met, and definitely smartest woman. Now I’m confident enough to say I *am* pretty smart, but the issue as I told him wasn’t that I was some rare, hyper intelligent woman, but rather that I was one of the few woman who persevered through the constant assault of sexism that pushes women out of “male” hobbies and careers. And my perserverance wasn’t even especially noble, I grew up in an abusive home and don’t always have a good enough sense to say “no, this is unhealthy”. So I stayed in that world. That and he just wasn’t exposed to women in a way where he got to see women intelligent women shine- his work and his indeed his personal life left him insulated- he knew no women in his specialty, and his hobbies were of the geek/nerd variety, most which have far fewer women (not that women don’t participate, just not many for all the reasons they are kept from the male dominated techie jobs. And of those, most had to take on cool girl personas to exist in the hobbies). (He also conflated technical savvy with intelligence, rather than a learner skill, complicating this view.)

And, I hate to say it, he was one of the more sensitive men I’ve known- open to ideas where he was getting it wrong. We talked about this a number of times, he would seem to “get it” or at least take interest in what I was saying rather than ruling it outright like so many men. Being a more sensitive, emotional man than what’s considered the “normal”, he suffered by varying from the patriarchal standard of toxic masculinity. He wanted to subscribe to the newsletter and read more.

But, it seemed like without constant reminders of how I really wasn’t that special for being a computer geek, or that knowing those things didn’t make me some crazy genius, he slipped back into what he knew and what society told him, that non-tech savvy women were not intelligent, and that the lack of women in his field meant only the wicked smart could do that work, and those women “smart enough” were exceptionally rare. “You could totally do this work. You’d be so good at it,” he’d tell me as a way of complimenting me and commenting on what he perceived to be my smarts. I’d answer, “I am sure I would be. But I’m also really good at what I do now, it pays better, and I love the work. Why would I switch careers?” “But you’re so smart and you’d be so good at it!” As if I was somehow throwing something away because I was using my smarts for something he didn’t understand well.

(Sigh) I haven’t even finished the article. Just this thought process, the idea that the few woman who persist in male dominated fields are some how above and beyond most women’s skills (save maybe an unhealthy perserverance), needed to be commented on. Cuz this shit run so deep. Men think it. And so do many women. So loud and self reinforcing is the gender essentialism horn that almost everyone buys into it.
posted by [insert clever name here] at 8:01 PM on January 2 [31 favorites]

This is an excellent article. I'd like to add something, but there's hardly anything left to add; the article and sciatrix's excellent follow-up pretty much cover it.

I will note that some of the best researchers who have published work focused on sex differences in the human brain will freely express a much more nuanced view in personal conversations. For example, I was in a small seminar with one of the first neuroscientists to focus on sex differences in functional brain activity, originally using PET starting in the 70s or 80s, so he's a pretty late career guy who's been thinking about this a long time. His presentation focused on the robustness and replicability of some of the sex-difference findings, for example, differences in activation patterns during spatial reasoning tasks, language tasks, etc., and he made a very compelling case that the results are reliable.

But, during the seminar, someone asked, "So, do you think you could predict someone's gender based only on their activation patterns during these tasks?" And he responded without hesitation, "Oh no, not reliably." At the end, I asked him, "What do you think the origin of these differences are? Do you think these are caused only by sex, or the result of a lifetime of acculturation?" His response was something like, "That's a very interesting question. I don't know but culture probably plays a strong role." Then he told us with some excitement about a collaboration he was just starting with researchers in South Africa who have some Khoisan volunteers to see whether these effects are different in a very non-WEIRD culture.

It's frustrating to me that this much more nuanced approach by researchers who I otherwise would tend to consider in the "other camp" from myself on this issue isn't as well represented in the popular press or even the scientific literature. High profile journals prefer clean narratives, and sometimes researchers who regularly publish in Science, Nature and the like will smooth over their own reservations, hesitations, and nuanced perspectives on their work, sacrificing complexity on the altar of Impact Factor. The result ends up being that simplistic ideas like "male brain" and "female brain" appear to have more currency and support by high-quality research than they really do.

I think many neuroscientists fail to comprehend the complexity of the human brain, or the sheer number of things that can modify and interact with brain function.

Quoted for frikkin' truth.
posted by biogeo at 8:27 PM on January 2 [16 favorites]

"Trying to understand the brain using fMRI is like trying to understand what's going on inside a building by measuring what goes in and out of the plumbing."

There's a less snarky but substantially similar version of this, that's actually a pretty helpful way of understanding the limitations of fMRI. If you have an electronic circuit board, and you don't know what it does, or you want to diagnose a problem with it, you can actually learn a fair amount by using a thermal imaging camera to see what components are using power at what times and under what conditions. If you had no idea how a computer works, you could try to figure it out by looking at the motherboard with an IR camera. You'd learn something very useful about the hardware, but you'd never figure out how the CPU works, how transistors act as switches to direct the flow of current, or anything significant about the architecture of a computer system. You'd never be able to build one yourself, or use the thermal imaging data alone to make any detailed predictions about the kind of information the computer is processing at any time.*

fMRI is a lot like that. Sex differences in fMRI signals can tell you that men and women are recruiting different neural systems to solve certain problems (though the magnitude of those differences is generally less than the variability within either sex), but they can't tell you why or what it means for differences in how men and women may process information, if indeed there is any such difference. On the other hand, what it can tell you, as this article points out, is that there are many more than two basic patterns of dynamic response to stimuli, and the binary dimensions "male" and "female" are insufficient to describe the range of patterns of energy use we see in the brain.

* Small caveat that you could probably actually make some decent predictions by training a machine learning algorithm on your thermal imaging dataset, just as people now do with fMRI, but I think it's debatable as to whether you can really say you've understood anything about the system you're studying by doing that.
posted by biogeo at 9:09 PM on January 2 [12 favorites]

One of the smartest people he’d ever met, and definitely smartest woman.

oh thank god you broke up with him. the arrogant delusion of men who think that because you're smarter than they are, you're also smarter than most other women! I've never met a man as smart as me [1] but I'm not even in the top three most brilliant women I know.

the worst part is when they say to you something that is completely true, like that you're brilliant, but they clearly don't even know it's true, and you can tell they are not capable of understanding that it is true or why it is true - they think they're flattering you. encouraging you, perhaps.

[1] no insult to the ones I have met is intended; they have other virtues. their gentle masculine natures suit them wonderfully well for admiring and supporting me in my endeavors and adventures. this is a complementary role and in no wise an inferior one.
posted by queenofbithynia at 10:03 PM on January 2 [19 favorites]

How does this square with the fact that there are observed differences in (binary*) transgender brains, both before and after beginning hormones? For example, trans male brains were found to share more similarity with cis male brains than cis female; and the reverse for trans women. AFAIK, they didn't follow the same people, but there have been studies that show trans male brains after hormones develop structures more like cis men. (Even more? It's not clear.)

Anyway, there obviously is a spectrum and I know people at points all along it, but I'm always on high alert when I read these things. Especially since she said she was a "tomboy." I've been invalidated so many times by self-identified former tomboys because they think I'm denying my true nature as a woman and buying into the stereotypical binary because I don't think it's okay to be a masculine woman.

*AFAIK there have been no studies of self-identified non-binary/genderqueer etc people
posted by AFABulous at 7:03 AM on January 3 [3 favorites]

My understanding is that there are some regions that do vary more consistently with gender or sexual orientation, but that these regions are small and probably participate in quite specific processes (like governing gender self-concept, etc) as opposed to leading to global differences in cognition. Trans biologist Joan Roughgarden (Evolution's Rainbow) has talked about this, I think.
posted by en forme de poire at 8:50 AM on January 3 [3 favorites]

I get feeling nervy about that, AFABulous, and it's definitely something I try to keep in mind when I talk about things like this. The thing I generally try to nudge my fellow butch/GNC women making that particular social error into remembering is that look, gender is about what feels comfortable. Socialization plays into that, but our responses to the experiences that we have shape our feelings and relationship to gender identity as we go along.

(And I mean, there's discomfort going both ways, I think--I can't be the only gender-non-conforming woman out there who feels a cultural pressure to identify as nonbinary instead, because every time I try to evaluate my gender presentation or talk about the specific subcategory of gender I inhabit I find myself lumped with people who don't identify the way I do. But this identity and presentation is how I feel comfortable, so I cling to it regardless. On the other hand, my partner feels most comfortable identifying strongly as nonbinary, so I respect that identity, too. It's possible to have these different perspectives coexisting without invalidating each other, I hope, and I try to be careful about that.

All of this is why, incidentally, I chose not to work on humans in my PhD. I didn't trust myself to handle such sensitive topics well enough; I was afraid of my science being twisted into narratives used to bludgeon people. Sometimes knowing how things work is terrifying. I think I'd make a different choice now, but I can't be sure.)

Regarding the observed differences in brains studies, there's a couple of issues with that. One of them is that our brain structures change alongside our experiences and our behaviors. If trans men after hormones and--as importantly--after social transition are now experiencing a vastly different social environment, that alone could actually change brain structures to follow. The brain is not an infinitely plastic thing, but there's a definite tendency to forget among neuroscientists (and especially those neuroscientists particularly concerned with neuroanatomical variation between groups) that the brain changes in response to behavior and experiences just as brains determine behavior in relationship to experience.

So it makes total sense to me that trans men who are men--who occupy the social space of men, who think like men, who are men and have male minds and approaches--would have brains that more similarly resemble other men, including cis men, who have had those lifetimes of experience. Just as trans women could reasonably expect to have brains that resemble those of cis women.

(This is, btw, also the case for studies of neurological mechanisms more generally and studies of mechanisms underlying evolutionary change over time. There's a tendency for people trying to understand the how of a particular process to assume that that how is immutable and unchangeable, as if you can't walk into that factory and start tweaking machines to produce a pipeline for a totally different product. Those kinds of regulatory changes mean that the how can't be the ultimate explanation for the why, and when people confuse the two this can result in some really frustrating work.)

They can't have followed the same people for the second study because I think the first study you're referring to is probably a mixture of this one by Zhou et al., (with a follow-up here) and this one here by Garcia-Falgueras and Swaab which is not MRI work--it's immunohistochemistry work studying the size of the central nucleus of the bed nucleus of the stria terminalis (whew) and the size of another substructure of a nucleus of the anterior hypothalamus. And, ah, you can't really follow up with that because all the samples used in the study were dead at the time of study. (In fact, six patients were used in all three papers.) These studies to my knowledge also looked only at trans women, not trans men.

So it's important to note on these studies that you literally cannot observe these structures via fMRI or even a structural MRI. They're only distinguishable from the other parts of the larger structures by the way they result when stained with particular antibodies. That's fine, but it means that you cannot study them across time in humans, and the only populations of humans you can study are dead ones. In studies like this, that death usually comes after... well, a lifetime of having transitioned and experienced a whole life behind them identifying and relating to the world as a person identifying with their gender ID. Which pulls me back to my point about brains changing over time. These researchers did, to their credit, try to control for the possibility of HRT changing the brains of the women they studied--but they didn't (because it isn't actually possible to do so) control for, well, the practice that you get over time being comfortable with your given gender identity. These aren't necessarily things we could use to, say, screen children to find out who is "really" trans and who is not.

And the second study you're mentioning would probably have been structural MRI, so it would have looked at different structures entirely--and forgive me, but I haven't got time to track them down right now. That being said, that study of changes in the brain during men in transition doesn't necessarily obviate the point that I'm making about the plasticity of brains and the way that our brains react to our experiences--and I should note, also, that those reactions are also intimately tied up with our emotional perception of and processing of the situations in which we find ourselves.

I guess a thing I'm trying to get at is that... there are people who prioritize respecting the identity of transgender people as a real and important thing on all sides of this research argument. There are also people who do not prioritize that respect on all sides, too. And for me, this is a thing I struggle with when I evaluate and study neurological variation that touches on gender and sexuality, because I'm terrified of any conclusions I do find being used as a weapon against people that I don't think are being well treated by the culture in which I live.

Good thing I'm only working on motivation to engage in sociosexual behavior in my nonhuman species, I guess? Ahahahaha, fff.
posted by sciatrix at 10:04 AM on January 3 [9 favorites]

(Also, I apologize if that came off as a massive text block. You can boil a lot of it down to: "the perspective of scientists who criticize research on innate brain differences between sexes is not remotely incompatible with valuing respect for the gender identity of specific individuals, regardless of their assigned sex as birth." I can, if you like, point you at a few authors in the field who are simultaneously very critical of this body of work whoalso specifically take pains to respect the validity of the gender identity of individuals, regardless of how and why that identity comes to form.

I just--I get wordy. I'll be taking a break for a while, I guess, unless I've totally misunderstood what you're saying?)
posted by sciatrix at 10:09 AM on January 3 [4 favorites]

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