Friday, May 05, 2017

Our Brains Are Different

A couple of years ago a workshop presenter at the Health & Law conference said that male and females brains are the same and the workshop attendees let her have it! She never submitted a workshop again.

As trans people we do our research and stay up to date on all the latest research about us, this is from 2011 but it is worth repeating.
White matter microstructure in female to male transsexuals before cross-sex hormonal treatment. A diffusion tensor imaging study
Journal of Psychiatric Research , Volume 45 , Issue 2 , 199 - 204
By Rametti, Giuseppina et al.

Some gray and white matter regions of the brain are sexually dimorphic. The best MRI technique for identifying subtle differences in white matter is diffusion tensor imaging (DTI). The purpose of this paper is to investigate whether white matter patterns in female to male (FtM) transsexuals before commencing cross-sex hormone treatment are more similar to that of their biological sex or to that of their gender identity.
ResultsIn controls, males have significantly higher FA values than females in the medial and posterior parts of the right superior longitudinal fasciculus (SLF), the forceps minor, and the corticospinal tract. Compared to control females, FtM showed higher FA values in posterior part of the right SLF, the forceps minor and corticospinal tract. Compared to control males, FtM showed only lower FA values in the corticospinal tract.

ConclusionsOur results show that the white matter microstructure pattern in untreated FtM transsexuals is closer to the pattern of subjects who share their gender identity (males) than those who share their biological sex (females). Our results provide evidence for an inherent difference in the brain structure of FtM transsexuals.
Other research has found similar results, in a 2005 study “A Sex Difference in the Human Brain and its Relation to Transsexuality” found,
In summary, our observations suggest that the small size of the BSTc in male-to-female transsexuals cannot be explained by differences in adult sex hormone levels, but is established during development by an organizing action of sex hormones, an idea supported by the fact that neonatal gonadectomy of male rats and androgenization of the female rats indeed induced significant changes in the number of neurons of the BST and suppressed its sexual dimorphism [17,18].

Considered together with information from animals, then our study supports the hypothesis that gender identity alterations may develop as a result of an altered interaction between the development of the brain and sex hormones [5,6]. The direct action of genetic factors should also be considered on the basis of animal experiments [24].
Or the 2016 Scientific America article,
Is There Something Unique about the Transgender Brain?
Imaging studies and other research suggest that there is a biological basis for transgender identity
By Francine Russo
January 1, 2016

Some children insist, from the moment they can speak, that they are not the gender indicated by their biological sex. So where does this knowledge reside? And is it possible to discern a genetic or anatomical basis for transgender identity? Exploration of these questions is relatively new, but there is a bit of evidence for a genetic basis. Identical twins are somewhat more likely than fraternal twins to both be trans.
Overall the weight of these studies and others points strongly toward a biological basis for gender dysphoria. But given the variety of transgender people and the variation in the brains of men and women generally, it will be a long time, if ever, before a doctor can do a brain scan on a child and say, “Yes, this child is trans.”
However, we cannot fall in to the trap that this might be the only vector to cause gender dysphoria there maybe many other causes or a combination of causes that make us trans.

1 comment:

  1. This is a very interesting post.
    I do know that children sometimes have a very strong inclination to view themselves as the other sex when some biological evidence supports this view of theirs. I really never thought about the brains being different, as such.

    Interesting about identical twins.