Category Archives: Misc.

Polymicrogyria of the Unilateral Temporal Lobe in a Transsexual Patient-Case Report – a Review

This is an interesting case study about an abnormality in a trans woman’s brain. The trans woman did not have epilepsy or any other neurological condition.

This brain abnormality may or may not be related to gender dysphoria. We only have one case here.

The authors suggest that future studies of people with gender dysphoria should look for “possible brain abnormalities of any kind [in] MRI scans.”

Details of the study:

The trans woman had a condition called polymicrogyria in her left temporal lobe. Polymicrogyria is exactly what it sounds like – if you speak Latin.

Basically we all have ridges or folds in the cerebral cortex of our brains called gyri (one gyrus, two gyri). In polymicrogyria the brain develops many small folds during the prenatal period.

Polymicrogyria can have small or severe effects, depending on where it is in the brain. It is most typically associated with epilepsy.

Polymicrogyria in a larger area of the brain is associated with severe problems like developmental delays, problems with speech and swallowing, muscle weakness or paralysis, and seizures that are difficult to control.

The cause of polymicrogyria is generally unknown. In some cases it is caused by prenatal infections or other problems and in some cases there is a genetic link.

Mild cases of polymicrogyria may be more widespread than we realize.

In this case, the polymicrogyria were in a limited area of the brain and were not causing any problems. The question is, could they be causing gender dysphoria?

At this point, we don’t know, we just have an interesting result to follow up on.

Where exactly is the polymicrogyria in this case study? The English of the study is fairly awkward, but this is what I think they are saying.

The lateral sulcus on the left side is missing the ascending branch. In addition, the posterior branch ends at the preoccipital notch because it is interrupted by the polymicrogyria.

The polymicrogyria are in the parietotemporal region.

This would, I think, be near the temporoparietal junction  (TPJ).*

File:Brain - Lobes - Temporoparietal junction.png

The TPJ integrates information and has many functions, from theory of mind and moral behavior to paying attention. What makes the TPJ interesting in discussing gender dysphoria is that the TPJ also plays a role in integrating multisensory signals from your body. The TPJ may be part of how we experience a sense of body self-consciousness, i.e. identifying with your body, self-location, and first-person perspective.

Stimulating the TPJ can cause an out-of-body experience (OBE). (Fascinating study here.)

This study concludes:

“These results suggest that the TPJ is a crucial structure for the conscious experience of the normal self, mediating spatial unity of self and body, and also suggest that impaired processing at the TPJ may lead to pathological selves such as OBEs.”

So it might be possible that polymicrogyria in the TPJ would cause someone to experience a disconnect from their body. Could that cause or contribute to gender dysphoria?

Polymicrogyria are created during fetal development and are not influenced by the postnatal environment, so dysphoria about the body could not cause polymicrogyria.

In addition, if polymicrogyria plays a role in gender dysphoria, it is not related to sex hormones or normal differences between males and females. Polymicrogyria are not a normal part of the brain.

There might, however, be multiple factors that contribute to developing gender dysphoria. Damage to the TPJ might be just one factor or it might only be a factor in some cases.

Another possibility would be that something happened to this trans woman prenatally that caused her to develop gender dysphoria and to have polymicrogyria.

Interestingly, an earlier study of gynephilic** trans women’s brains found that the trans women had larger gray matter volumes than cis men or women in the “right temporo-parietal junction (around the angular gyrus and in the posterior portion of the superior temporal gyrus).”*** You can read more here. This is not the same as what the current study found – polymicrogyria on the left side of the brain – but it is interesting that the TPJ seems to be involved in both studies.

Obviously without more data, this is all very hypothetical.

It would be useful to have more studies that look at the TPJ in the brains of trans and cis people. As always, controls should include some gay and lesbian cis people.

Original Study:

Polymicrogyria of the Unilateral Temporal Lobe in a Transsexual Patient—Case Report by Starcevic, Ana; Zigic, Dusica Markovic; Filipovic, Branislav in Neuroscience and Medicine4.4 (Dec 2013): 263-266.

For more information on polymicrogyria:

Genetics Home Reference on Polymicrogyria (a service of the National Institutes of Health).

Polymicrogyria Awareness group.

*Parietotemporal region may be another way to say temporoparietal junction, I’m not sure. The translation of the article has a lot of problems.

**Gynephilic = attracted to women. Some studies of brain sex look only at trans women (born male) attracted to men, some look only at trans women attracted to women. Studies comparing trans women attracted to men to cis men attracted to women can’t be sure if their results are due to sexual orientation or gender. However, studies that look only at trans women attracted to women leave out half of trans women and may miss important aspects of gender dysphoria. We need more studies that include cis gay and lesbian controls.

The trans woman in the current study had a wife and an ex-wife. She had experienced gender dysphoria since age four. She had a degree in electrical sciences and was “working two jobs which are not in [her] field of professional interest.”

*** The original text refers to the superior temporal gurus. A cool idea, but probably a typo.

Thanks to Wikipedia for the image.

Prenatal exposure to anticonvulsants and psychosexual development

This is a 1999 study with intriguing results.

The authors followed-up on 243 people who were exposed to phenobarbital and/or phenytoin before they were born.

Three of them had medically and socially transitioned; two trans men (born female) and one trans woman (born male).*

Among the 147 people who they were able to speak to, the authors also found three possible cases of gender dysphoria.

One woman had had cross-gender feelings from childhood until age 21 when she became pregnant.

Another woman “did not feel very comfortable with her femininity, but had made the conscious decision to ‘to behave like a woman.'”

Finally one of the men “denied the changes his body had undergone during puberty. He claimed to have a female’s voice (although the researcher heard a male voice), he denied having facial hair (although he had a moustache), and he denied having erections.”

There were also two gay men among the people they interviewed.

The authors looked at a control group of people born at their hospital during the same time period (1957-1972). None of them had transitioned, none of them reported gender dysphoria, and none of them were gay.

In addition, the authors compared the number of trans people in their sample to the general population in the Netherlands and the difference was statistically significant.

Clearly, something is going on here.

Why hasn’t anyone followed up on this? Well, for one thing, phenobarbital and phenytoin are no longer given to pregnant women. We don’t need to worry about any possible risks from people taking them. Besides, it would be hard to find people born recently who had been exposed to phenobarbital before birth.

On the other hand, the results suggest that it may be worth looking for connections between gender dysphoria and medications mothers take during pregnancy.

The authors of the study theorized that in order to metabolize the anti-convulsants, the fetus would produce microsomal enzymes in its liver. Then, “these enzymes also catabolize steroid hormones so that the steroids cannot properly exert their action on brain and body.”

This would suggest that prenatal hormones were involved in developing gender dysphoria.

It might be, however, that the medications themselves affected the babies.  Both phenobarbital and phenytoin are known to cause fetal abnormalities.

It could also be that the medications affected the mothers’ eggs rather than affecting the baby.

If the mothers breastfeed the babies and continued to take the drugs, they might have affected the babies’ development after birth.

Another factor to consider is that phenytoin may cause babies to develop ambiguous genitals. That in turn might affect how children are raised, including the possibility of being raised as a sex different from your genetic sex. It would be useful to know if any of the people in the study had ambiguous genitals.

It’s also possible that the drugs themselves weren’t the issue here. The mothers were taking the drugs for a reason. Could the mothers have passed on genes related to epilepsy or emotional problems that also affected gender identity? Could being raised by a mother with epilepsy or emotional problems affect gender dysphoria?

In this study, one of the trans men had a mother with epilepsy; the mothers of the other trans man and the trans woman did not. It’s not clear from the article if the two non-epileptic mothers took phenobarbital for emotional problems or pregnancy-related complaints.

There’s no information given on the mothers of the three people who did not transition but had some symptoms of gender dysphoria.

This is not strong evidence of a link between epilepsy and gender dysphoria, but it might be worthwhile for someone to do a study looking at epilepsy in the families of people with gender dysphoria.

We don’t know anything about the non-epileptic mother of the trans man as the trans men did not participate in the follow-up interviews.

However, among the people the authors interviewed, cross-gender behavior was not related to parental psychiatric problems, family problems during childhood, or socioeconomic status. This should not be surprising – cross-gender behaviors are not a problem. They are also not the same thing as gender dysphoria.

Which leaves us where we started: it is possible that something about the mothers or their genes affected the children who developed gender dysphoria.

The study provides some other evidence about exposure to the medications and psychosexual development. The authors interviewed 147 people in depth and looked at other possible traits that might have been influenced if the prenatal hormones were abnormal. This group did not include the two trans men, but it did include the trans woman and the three people with some symptoms of gender dysphoria.

They did not find statistically significant differences between the people exposed to anti-convulsants and the controls in gender role behavior in childhood or adulthood, sexual orientation,** physical development during puberty, feelings about puberty, adult satisfaction with secondary sex characteristics, or experience of their first sexual activities.

In general, the overall psychosexual development of people exposed to the anti-convulsants prenatally was not different from the people who were not exposed.

They did find, however, that there were more people in the group exposed to anti-convulsants who had high cross-gender behavior scores than in the control group. In other words, the group averages were comparable, but there were more people who were very gender non-conforming in the group that had been exposed to anti-convulsants.

So did the pre-natal hormones matter? We still don’t have the answer.

It could be that the anti-convulsants only affected some babies’ hormones. It could be that they affected the hormones, but that this isn’t enough to cause gender dysphoria in most people; perhaps the environment plays a role. It could be that the hormones are irrelevant and the medications directly affected the babies or the mothers’ eggs. It could be that something about the mothers who needed to take medications was different and affected their children.

What we do know is that taking these medications was linked to developing gender dysphoria severe enough for people to transition.

It’s a result worth some new research – does exposure to other medications affect gender dysphoria? does it matter if the father is exposed to the medication? are there any links between epilepsy and gender dysphoria?

Original Article:

Prenatal exposure to anticonvulsants and psychosexual development by Dessens AB, Cohen-Kettenis PT, Mellenbergh GJ, vd Poll N, Koppe JG, Boer K. in Arch Sex Behav. 1999 Feb;28(1):31-44.

 

 

*Some details about the transitioners:

The trans woman was exposed to phenobarbital during weeks 18-40 gestational age and one of the trans men was exposed to it during weeks 36-42.  Their mothers did not have epilepsy. They authors don’t mention the dose they took, but earlier they say that mothers who didn’t have epilepsy generally took a lower dose.

The other trans man was exposed to phenobarbitol, phenytoin, and amphetamines throughout the pregnancy. His mother had epilepsy.

All three of them started hormone therapy at age 18-23 and had sex reassignment surgery at 20-25. The trans woman had identified as a girl since early childhood; the authors did not have data on the trans men.

**However for sexual orientation in males, the p-value was 0.07 which is close to statistically significant. (There were two gay men in the group exposed to anti-convulsants and none in the control group.)

The strange-face-in-the-mirror illusion

Interesting blog about a mirror illusion – if you stare too long, your face seems to become distorted and you may even see a stranger there. I wonder what role this plays in body dysmorphia? Could it be that some people see distortions after a shorter time spent looking in the mirror? Not directly related to gender dysphoria, but a good reason not to spend too much time looking at mirrors.

Mind Hacks

An intriguing article has just been published in the journal Perception about a never-before-described visual illusion where your own reflection in the mirror seems to become distorted and shifts identity.

To trigger the illusion you need to stare at your own reflection in a dimly lit room. The author, Italian psychologist Giovanni Caputo, describes his set up which seems to reliably trigger the illusion: you need a room lit only by a dim lamp (he suggests a 25W bulb) that is placed behind the sitter, while the participant stares into a large mirror placed about 40 cm in front.

The participant just has to gaze at his or her reflected face within the mirror and usually “after less than a minute, the observer began to perceive the strange-face illusion”.

The set-up was tried out on 50 people, and the effects they describe are quite striking:

At the end of a…

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Physical Appearance and Voice in Male-To-Female Transsexuals

This is an interesting study of the importance of physical appearance versus voice for passing. The authors used two panels to rate the “femaleness” of male-to-female transsexuals. They rated audio tapes, video tapes, and videos without sound.

The judges were randomly divided into two groups. “Each group of judges rated half of the subjects from the auditory-only mode and the audiovisual mode, and half of the subjects from the visual-only mode and the audiovisual mode.” This controlled for possible order or sequence effects.

The panelists did not know that they were listening to or looking at trans women.

The study found that overall the video alone was most likely to be rated female, the video with sound was next most likely, and the sound alone was least likely to be rated female.

Thus, appearance and voice work together when figuring out someone’s gender. To put it another way, a feminine appearance can make a voice sound more feminine.

There were, however, a few individuals who were rated more feminine without the visual appearance. For them, a feminine voice helped counteract a less-feminine appearance.

The study also found that in the auditory only mode of presentation, the average fundamental frequency of the voice was correlated with a female rating. The voice itself makes a difference.

It would have been good to have had the panels rate some cis women’s voices and photos for comparison.

This is a well-designed study that supports the conclusions the authors make. It underlines the importance of working on multiple factors for passing.

The authors of the study conclude:

One implication of this finding is, at any rate, that the success of vocal training in male-to-female transsexuals is not solely dependent on vocal characteristics, and that any assessment of the success of voice training should take into account the possible contribution of a client’s physical appearance. Whether or not the increase of fundamental frequency in a particular male-to-female transsexual is sufficient is probably also determined by the acceptability of the client’s physical appearance. With a physical appearance that rates high for femaleness an individual with a less female voice may nonetheless be accepted as a woman. Conversely, a female voice does not automatically guarantee that an individual will be accepted as a woman if physical appearance is not acceptable. As acceptability of physical appearance can influence perception of femaleness of the voice, speech pathologists involved in gender teams may consider devoting special attention to training clients with respect to physical markers of femaleness such as in clothing and makeup. Since physical appearance can apparently positively influence listeners’ judgment of the femaleness of the voice, extra attention to physical appearance seems worthwhile, particularly in those cases where efforts to alter an individual’s voice proved less successful and where other procedures (voice change surgery) are not an option.

Original Article:

Physical Appearance and Voice in Male-To-Female Transsexuals by John Van Borsel, Griet De Cuypere, Hilde Van den Berghe in J Voice. 2001 Dec;15(4):570-5.

Bold added by George Davis.