In addtion to a couple of centers that seem to determine your gender or your sexual orientation, which have been identified in MTF to be like cis females and in FTM like in cis males. Now, the study below furthers the idea that the MTF GID is a "whole female brain" issue, and not just one center.

Kate D

(Now, belive it... or not; No BS)

J Psychiatr Res. 2011 Jul;45(7):949-54. Epub 2010 Dec 30.
The microstructure of white matter in male to female transsexuals before cross-sex hormonal treatment. A DTI study.
Rametti G, Carrillo B, Gómez-Gil E, Junque C, Zubiarre-Elorza L, Segovia S, Gomez A, Guillamon A.
SourceClinical Institute of Neuroscience, Hospital Clínic, Barcelona, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Spain.

Abstract
BACKGROUND: Diffusion tensor imaging (DTI) has been shown to be sensitive in detecting white matter differences between sexes. Before cross-sex hormone treatment female to male transsexuals (FtM) differ from females but not from males in several brain fibers. The purpose of this paper is to investigate whether white matter patterns in male to female (MtF) transsexuals before commencing cross-sex hormone treatment are also more similar to those of their biological sex or whether they are more similar to those of their gender identity.

METHOD: DTI was performed in 18 MtF transsexuals and 19 male and 19 female controls scanned with a 3 T Trio Tim Magneton. Fractional anisotropy (FA) was performed on white matter of the whole brain, which was spatially analyzed using Tract-Based Spatial Statistics.

RESULTS: MtF transsexuals differed from both male and female controls bilaterally in the superior longitudinal fasciculus, the right anterior cingulum, the right forceps minor, and the right corticospinal tract.

CONCLUSIONS: Our results show that the white matter microstructure pattern in untreated MtF transsexuals falls halfway between the pattern of male and female controls. The nature of these differences suggests that some fasciculi do not complete the masculinization process in MtF transsexuals during brain development.

Very interesting. More and more scientific data is verifying what should just be accepted from the start - if someone says their brain is one sex different from their body, then it should be accepted. It makes me wonder, however, if a trans person did not fit within the expected results of this study whether they would be considered "less trans".

So transwomens' brains fall halfway between the cismale and cisfemale norms. So it looks like if you have incompletely masculinized areas of the brain, it defaults to female. It's like having a partially built bridge, it might as well not exist.

Transmen, on the other hand, according to the study, have brain fibers that do not differ from cismales. Their bridges are completely built. This makes me wonder how many cis-women are walking around with halfway built bridges in their heads, not knowing how close they came to being trans. This also makes me wonder if this accounts for the supposed higher instances of transwomen vs. transmen. It seems like the brain must be fully on board to allow for a transman incident, and only partially onboard to allow for a transwoman incident.

Of course, everything I'm saying here is pure speculation.

Quote from: Sunnynight on July 26, 2011, 04:11:35 PM
This also makes me wonder if this accounts for the supposed higher instances of transwomen vs. transmen. It seems like the brain must be fully on board to allow for a transman incident, and only partially onboard to allow for a transwoman incident.

Or it could be that more people who could be transmen have been socialized to identify themselves as lesbians.

I'm sorry, I don't understand that conclusion from the abstract you posted? It did not say MtFs have a "whole female brain," it claimed that MtFs have a brain that's halfway between male and female norms. That does not exactly agree with the assumption we have all been operating under.

Personally, I think it would offer more insight if the sample size was much greater and the distribution of the results in terms of their magnitude was described (certainly it is not exactly the same for everyone). But honestly those findings would not seem surprising? Obviously there is something different going on in the typical trans brain than the typical cis brain, if anything because of sexuality seeming statistically more closely tied to a person's birth gender than their identified gender.

I understand the desire for vindication but I think that's a convenient interpretation of a study that basically found its participants to be NOT transsexual in the classic view, having female brains in male bodies, but instead having underdeveloped male brains. Just because it says that there's a physiological basis for GID does not mean it's something you want to take up a flag and start promoting, because frankly this is the kind of study a bigoted lawmaker will refer to as evidence that "those pedophile transsexuals," or whatever, should not be allowed status as a female, but rather be "fixed" into a male role.

Yep, all is in the head --- including your body hon, and inclusive that small head. :-)
Axelle

EDIT: funnily enough no one mentioned the "lower stratum of the BSTc area of the hypothalamus", just LOVE that stuff.
I guess MRI or Ct scan can't really get there, so only dissectioned trans-woman bodies showed different neuron counts to cis-males, incl. homosexual males = hetero males.

Furthermore, XY brains grow bigger in volume --- does that leave us with more "rationality" connection?
Sometimes it feels like it, and mostly I don't mind.

Lastly being 3 sigma above average IQ doesn't hurt either. Starting to sound elitist? Sooorry!
So is 1/2 female then .... good or bad?
Go figure

Quote from: Sunnynight on July 26, 2011, 03:52:55 PM
It makes me wonder, however, if a trans person did not fit within the expected results of this study whether they would be considered "less trans".

The topic of the brain structures of gay FtMs and lesbian MtFs came up in another thread.  We were wondering if brain scans would indicate "straight cis-female" and "straight cis-male."  I'm tired and headed to bed, so forgive me for not checking the research.  If anyone knows of comparisons done with these brain structures I would love to know. 

To me, it sounds like its just another coat of paint on the nature vs.  nuture argument that the GLB community has been fighting (without success) for years.  As others have said, would it just be one more means of division within our community between the haves and the have nots.  Does someone's brain scan that goes against the expected outcome then be denied treatment?

of course its all in my head.....that's why it's listed as psychological in the DSM IV manual!