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Comment by codesushi42 | Hacker News Reader

How can you be so sure that your brain structure is actually different? Are there any scientific tests that can be performed to support this?

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Dick Swaab of the Netherlands Institute for Neuroscience is a pioneer in the neuroscience underlying gender identity. In the mid-1990s, his group examined the postmortem brains of six transgender women and reported that the size of the central subdivision of the bed nucleus of the stria terminalis (BSTc or BNSTc), a sexually dimorphic area in the forebrain known to be important to sexual behavior, was closer to that of cisgender women than cisgender men.[1] A follow-up study of autopsied brains also found similarities in the number of a certain class of neurons in the BSTc between transgender women and their cisgender counterparts—and between a transgender man and cisgender men.[2] These differences did not appear to be attributable to the influence of endogenous sex hormone fluctuations or hormone treatment in adulthood. In another study published in 2008, Swaab and a coauthor examined the postmortem volume of the INAH3 subnucleus, an area of the hypothalamus previously linked to sexual orientation. The researchers found that this region was about twice as big in cisgender men as in women, whether trans- or cisgender.[3]

[1] J.-N. Zhou et al., “A sex difference in the human brain and its relation to transsexuality,” Nature, 378:68-70, 1995. [2] F.P. Kruijver, “Male-to-female transsexuals have female neuron numbers in a limbic nucleus,” J Clin Endocrinol Metab, 85:2034-41, 2000. [3] A. Garcia-Falgueras, D. Swaab, “A sex difference in the hypothalamic uncinate nucleus: relationship to gender identity,” Brain, 131:3132-46, 2008.

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All of the above is from the first google result and about 30 seconds of searching. https://www.the-scientist.com/features/are-the-brains-of-tra...

So, yeah, science is beginning to try and understand this stuff.

I wonder if something like an MRI could allow medical professionals or diagnostic systems to automatically categorize this non-invasively?

When we reach a world where everyone has more star trek level medical care then a true survey of the population may allow for everyone to have improved lives.

Perhaps. I'm a little concerned that if this approach is used for diagnostics that it becomes another form of gatekeeping. (i.e. someone is transgender but denied treatment because their brain scans come up as cis.)

There's a dark side of everything, but there are people who believe they want to transition who then find out it doesn't help when they do. Being able to diagnostically assess the likelihood that it's the correct treatment would be good for everyone.

Conversely it could help someone who is in denial and experiencing disphoria to come to terms with themselves.

That would have to be an incredibly precise test though; if someone is in denial and you tell them "This test says there's only a 5% chance you're right", they will probably stay in denial.

Reminds me of XKCD's Significant comic: https://xkcd.com/882/

So, that gets complicated. What if medicine finds a certain physical trait that is prevalent in 90% of cases where people are trans? What does that mean for the other 10%? Odds are good their lives just got WAY harder. Coupled with a history of being mistreated by the medical industry, there's quite a lot of (rational, imo) fear in the trans community about medical diagnoses.

Other commenters are linking to _studies_, I think parent is asking if GP had a _test_ done for them that specifically showed them their brain structure. Big difference between a study and a consumer-/patient- ready product. At least, studies could mean the product is forthcoming.

When I search "brain structure test" I get IQ/personality quiz web pages. "brain structure medical procedure" gets me general information on brain anatomy and glossaries of neurosurgical terms. "{gender|trans} identity brain structure procedure" similarly returns scholarly information.

Nothing on a procedure I could schedule with my doctor, but maybe it's easier to ask my doctor than use Google. Maybe someone with better Google-fu could suggest better keywords. Has anyone done this or asked their doctor about it? I know I'd be interested in what my brain looks like in this regard!

The article she offered directly links to them...

Was she part of the study?

If someone is left-handed, and left-handedness has been shown to be very strongly correlated with a different brain structure, would you challenge them similarly if they state that they have a different brain structure because they are left handed?

Do you need to personally participate in studies to know anything about your body?

I would if I were to undergo an invasive medical procedure.

Ah, I didn't realize how specific your use of "your" was, perhaps because she didn't make any claims about the structure of her own brain.

Baltimore Maryland, is that you?

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