This MRI study of brain changes in 18 women who are injecting testosterone to “transition” to male is getting a bit of traction in the press. (Apparently the researchers, from the European College of Neuropsychopharmacology, have only announced their findings; there is no published paper in the literature that I could find.)
Update: In response to several comments I’ve received, as well as some fruitful Twitter discussions with scientists and linguists, I would like to clarify a couple of points:
- By itself, this study tells us nothing definitive about the possible impact of testosterone on the female brain. Particularly since the researchers did not couple the MRI with pre- and post-testosterone cognitive-linguistic testing, we don’t know whether the reduction in gray matter in the subjects’ brains correlates with reduced verbal fluency. Even more informative would be functional MRI studies (fMRI) while the subjects are performing linguistic tasks. Obviously, the results should spur researchers to do studies on more subjects, along with objective linguistic test measures to see whether results are replicated and whether they do indicate a decline in linguistic skills. I have found 3 studies in the research literature which point to a statistically significant decline in verbal fluency in women who have increased circulating testosterone. I will be writing a post about those studies in the near future.
- Secondly, it is my opinion that the results of this study, along with a few others which assessed verbal fluency, should be shared with women who are contemplating testosterone “therapy.” It’s quite likely some of these women would go on to inject “T” anyway, but it’s also possible some would choose not to. Knowledge is power.
- To discover whether testosterone-induced brain changes seen on MRI are permanent, another important line of research would be to longitudinally study women who want to inject “T” for only a limited time period. Multiple followup MRIs (and cognitive-linguistic testing) would provide insight into whether testosterone’s effects are permanent or temporary in these cases.
The big news is that “T” administered to women results in decreased volume of gray matter in the all-important zone of language in the brain, Broca and Wernicke’s areas. And these changes occurred after only 4 weeks of testosterone treatment.
According to one of the researchers, Dr. Andreas Hahn,
It has been known for some time that higher testosterone is linked to smaller vocabulary in children and that verbal fluency skills decrease in female-to-male transsexuals after testosterone treatment. This fits in well with our finding of decreased grey matter volume. However, the strengthening of the white matter in these areas was a surprise. We think that when it comes to certain language skills, the loss of grey matter outweighs the strengthened white matter connection.
Think about that. “It has been known for some time…that verbal fluency skills decrease in female-to-male transsexuals….when it comes to certain language skills, the loss of grey matter…” We are potentially talking about a loss of brain cells here.
Call me alarmist, but this is such major news that all the gender specialists should be sitting up and taking notice and–oh, I don’t know, maybe expressing a few doubts about the wisdom of injecting male sex hormones into females? Or asking the women about to start on “T” whether a potential loss of neurons is something they actually want for their future? Seems there might be some need to question whether a reduction in gray matter of the cerebral cortex is an acceptable risk to take for women who wish they were men?
The press coverage I’ve seen so far hasn’t hinted at any medical ethics concerns raised by the study results. For instance, the venerable Washington Post treats the whole thing as just another ha-ha “Men are from Mars, Women are from Venus” fluff piece. Heck, the title of the Post article is “Why Men Get Tongue-Tied.” They could at least have called it “Why Women are So Verbally Adept.” You know, throw a tiny bone to the fact that the subjects of this study were women?
Instead, it’s all about the differences in how men and women communicate–which admittedly, is an interesting corollary. But hang on a minute. How can they even draw those conclusions? This study didn’t compare men and women. The journalists are jabbering glibly about differences between men and women, but the study looked at 18 women who had been injecting themselves with testosterone for a month, not men.
But you can’t entirely blame the predictably shallow, politically correct press for ignoring the elephant in the room–or should I say, the guinea pigs. The researchers themselves only seem interested in how these results illuminate the differences between men and women–not on the rather sobering implications for “gender reassignment.” The opening paragraph of the press release says
Brain imaging shows that testosterone therapy given as part of sex reassignment changes the brain structures and the pathway associated with speech and verbal fluency. This result supports research that women in general may deal with speech and interaction differently than men.
So let me see if I follow. If endogenous hormones are largely responsible for some rather crucial brain and communication differences between ADULT men and women, how in the hell are transgender people “really” the opposite sex from birth (as the activists and specialists firmly believe), if it takes hormone treatment to actually differentiate their brains?
What we see is a real quantitative difference in brain structure after prolonged exposure to testosterone. This would have been impossible to understand without looking at a transsexual population. In more general terms, these findings may suggest that the genuine difference between the brains of women and men is substantially attributable to the effects of circulating sex hormones. Moreover, the hormonal influence on human brain structure goes beyond early developmental phases and is still present in adulthood.
Right. “Circulating sex hormones” make the man (or woman). So, aren’t the researchers then pretty much stating that people who claim to have brains “born in the wrong body” don’t actually have the brains of the opposite sex until they undergo cross-sex hormone treatment?
This intriguing neuroimaging study of transsexuals before and after their female-to-male gender reassignment suggests that even adult men and women differ in brain structure within regions involved in language and speech. In particular, female-to-male gender reassignment resulted in local brain matter decrease within language processing regions, which may explain why verbal abilities are often stronger in women.
Here’s an idea. How about we start doing some pre-treatment studies and surveys of young women who are considering “transition.” Hell, let’s ask the prepubescent girls and teens too, since the activists and gender docs seem to think the earlier they get on “T”, the better. Let’s ask them how they feel about a “brain matter decrease” that potentially could make them less adept with language. (We don’t know this but it’s a possibility).
Just a suggestion. Just a few words from the zone of language in this female brain, which has not been marinated in extra androgens, thank you very much.
Some other press coverage of this research. None mention that loss of gray matter in the zone of language might be cause for concern in “transitioning” females. In fact, they are all essentially rewrites of the press release provided by the researchers. I’d expect more from well established news outlets with high circulation, but that’s just me. (Tangentially, I did happen upon an interesting study showing higher circulating testosterone in children who stutter, inspiring me to look more deeply into the effects of testosterone on communication skills in the future.)