Thursday, 15 May 2008

Sex and the Brain

Part of a continuing series.

Sometimes I get confronted with dogmatic statements of the form "Gender is a Social Construct!". Often stated with great conviction. This has elements of truth - Gender Role is a Social Construct. But Gender itself is not.

From Science Daily, based on the paper Sex Differences in Neural Processing of Language Among Children Burman DD, Talin T, Booth JR, in Neuropsychologia Neuropsychologia
Volume 46, Issue 5, 2008, Pages 1349-1362 :
Although researchers have long agreed that girls have superior language abilities than boys, until now no one has clearly provided a biological basis that may account for their differences.

For the first time -- and in unambiguous findings -- researchers from Northwestern University and the University of Haifa show both that areas of the brain associated with language work harder in girls than in boys during language tasks, and that boys and girls rely on different parts of the brain when performing these tasks.
Using functional magnetic resonance imaging (fMRI), the researchers measured brain activity in 31 boys and in 31 girls aged 9 to 15 as they performed spelling and writing language tasks.

The tasks were delivered in two sensory modalities -- visual and auditory. When visually presented, the children read certain words without hearing them. Presented in an auditory mode, they heard words aloud but did not see them.

Using a complex statistical model, the researchers accounted for differences associated with age, gender, type of linguistic judgment, performance accuracy and the method -- written or spoken -- in which words were presented.

The researchers found that girls still showed significantly greater activation in language areas of the brain than boys. The information in the tasks got through to girls' language areas of the brain -- areas associated with abstract thinking through language. And their performance accuracy correlated with the degree of activation in some of these language areas.

To their astonishment, however, this was not at all the case for boys. In boys, accurate performance depended -- when reading words -- on how hard visual areas of the brain worked. In hearing words, boys' performance depended on how hard auditory areas of the brain worked.

Iy would be fascinating to see an equivalent experiment involving children diagnosed with Gender Identity Disorder. Adults and Adolescents too. It's my belief that for someone to be transsexual, only one part or complex of the brain need be cross-gendered. But it's probable that other parts will be too. I conjecture that the earlier the manifestation of symptoms, the more likely the brain will be more cross-gendered. I also conjecture that the cross-gendering won't be complete in the majority of cases: that the mind of a transsexual person will conform neither to a wholly male, nor a wholly female pattern, as a general rule.

The same probably applies to many in gender-atypical professions. Female engineers remain totally female, but I conjecture that parts of their brain to do with engineer-type-stuff (to use a technical term) would be somewhere near the middle, rather than at the far end of a "typically female profile".

It would fit. But many a beautiful theory has been slain by an ugly fact. Pending actual experimental results, such conjectures are only useful for suggesting areas of interest to concentrate on in experimentation.

Another area of research is not just to determine the facts, for the study is pretty conclusive to me. It's to find out the cause. Boys and girls of that age think differently, their brains are wired up differently. But why? How much is to do with socialisation and feedback mechanisms, how much is due to hormonal floods at puberty, and how much is pre-ordained in some unknown way by pre-natal factors, probably hormonal, going back to the first trimester?

In my view, the evidence that we have, scanty as it is, is that the latter predominates. How else to explain the 500-fold increase in incidence of transsexuality amongst genetic males exposed to DES in the first trimester? The evidence is that this inborn tendency is very strong in certain areas, and may even be nigh unchangeable in the area of sexual orientation. In Gender Identity, the situation may be more fluid, but even then, the conditioning required to cause the brain to develop in an un-natural fashion "against the grain" is the equivalent of producing bonsai children. Cruel, a low success rate, and with terrible side-effects in many or even most cases.

I wish researchers would do a bit less of the neo-Freudian psychological theorising, and a bit more measuring of how the brain works using fMRI scans. I just want to know, and not just for objective reasons. Let the cards fall as they may, but at least let's observe them, and not deal from the bottom of the deck. Then, armed with knowledge, we can address the moral and ethical issues with some confidence that we're not doing exactly the wrong thing due to the best of intentions.

Previous posts on Gender/Sex Differences in the Brain, and the use of MRI to detect them:

Brains, Genes, and Sexual Orientation in Men
Functional MagnetoResonanceTomography... and Transsexuality
A Reply from a Guy I used to know
Talk is Cheap
Thoughts on Gender
It starts with a kiss
Left, Right, Male and Female Brains
Brain Intersex
Brain Structure

That last one is particularly poignant. June 6, 2005. Only 4 weeks after the first symptoms of my spectacular change appeared. A time which was filled with endless tests and more tests, including an MRI scan. A time when I was finally able to search for data about transsexuality, not knowing whether to deny or accept, or even if denial was possible. It wasn't, of course. A time when the writing was on the wall, and I was summoning enough courage to read it, limiting myself to taking sneak peeks between my fingers. A time when I lay in the bath, observing the bodily changes, part of me terrified that my whole life to that point had ended, and that not only was there no return, but I desperately didn't want to go back into Hell even if that was possible.

My trip to the Gender Centre in Sydney was still two days in the future. There I would be told that my life story wasn't unique as I'd always thought, but utterly typical. I didn't know that. I'd learned a lot in 4 weeks, but there are limits! I was also told yhat changes like mine had happened to several other transsexual women. My first contact with a professional, an expert in the area of diagnosis, rather than treatment. I was TS, as I hoped/feared.

It was still three weeks before I started laser hair removal, and had my ears pierced. Nothing that couldn't be backtracked from, physically, though to me the decision to have my ears pierced was the decision to travel all the way to the end of the line.

To use a well-worn analogy, something of a cliche, I was no longer a caterpillar, but a chrysalis. Now a pretty butterfly, social or otherwise, was never me. It would have been nice in some ways, but really not how I saw myself. A particularly fascinating workaday moth, one not pretty, but possessing a certain beauty anyway, and far more interesting, that was more my style. Still is, come to think of it. I'm.... Happy. Me, Zoe. I hope my readers are too.


helen g said...

...A time when the writing was on the wall, and I was summoning enough courage to read it, limiting myself to taking sneak peeks between my fingers. A time when I lay in the bath, observing the bodily changes, part of me terrified that my whole life to that point had ended, and that not only was there no return, but I desperately didn't want to go back into Hell even if that was possible.

*sends hugs*

Zoe Brain said...

Thanks, Helen.

The only difference between my situation then, and that of most, is that this was all happening 2 months before I started HRT, rather than 2 months after.

A minor difference really. In some ways it made it easier, but in other ways more scary. There were no brakes. I just had to ride it out. Fortunately, I was going where I wanted to, desperately needed to in fact, anyway.

That was only 3 years ago. Less. I guess I really have come a long way, baby!

Hugs back atcha, Zoe

Karen said...

This reminds me of a Julia Serano spoken word poem, "Performance Piece", that begins with "If one more person tells me that 'all gender is performance' I think I am going to strangle them.". You can find a written form of the poem here.