Might be of interest. Brains

[Marla S]

Hi there.

There have been a few threads about the female brain working faster and such lately.
I thought this brand new study 'Changing your sex changes your brain: influences of testosterone and estrogen on adult human brain structure' might be of interest especially for those that are on the way to the better side.
It's scientific but readable.

Abstract

Objective: Sex hormones are not only involved in the formation of reproductive organs, but also induce sexually-dimorphic brain development and organization. Cross-sex hormone administration to transsexuals provides a unique possibility to study the effects of sex steroids on brain morphology in young adulthood.

Methods: Magnetic resonance brain images were made prior to, and during, cross-sex hormone treatment to study the influence of anti-androgen + estrogen treatment on brain morphology in eight young adult male-to-female transsexual human subjects and of androgen treatment in six female-to-male transsexuals.

Results: Compared with controls, anti-androgen + estrogen treatment decreased brain volumes of male-to-female subjects towards female proportions, while androgen treatment in female-to-male subjects increased total brain and hypothalamus volumes towards male proportions.

Conclusions: The findings suggest that, throughout life, gonadal hormones remain essential for maintaining aspects of sex-specific differences in the human brain.

The complete article, free of charge, from here PDF (http://www.eje-online.org/cgi/reprint/155/suppl_1/S107?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&author1=Kahn%2C+RS&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&fdate=1/1/2006&resourcetype=HWCIT) or HTML (http://www.eje-online.org/cgi/content/full/155/suppl_1/S107?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&author1=Kahn%2C+RS&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&fdate=1/1/2006&resourcetype=HWCIT)

PS: A goody for the FtMs. According to another study the hormones increase your (male) spatial ability performance, and leave the (female) verbal fluency untouched, whereas for the MtFs nothing changes ;)

[Joy Carter]

Interesting.:thinking: Gee I recall some where while I was being formed in the amniotic fluid of being asked what kinda brain I wanted. But I thought they said trains and asked for an empty compartment.:doh:

[Kieron Andrew]

PS: A goody for the FtMs. According to another study the hormones increase your (male) spatial ability performance, and leave the (female) verbal fluency untouched, whereas for the MtFs nothing changes ;)
oooerrrrrr wheres that Testosterone lol

[Marla S]

oooerrrrrr wheres that Testosterone lol


I see, Sir. Generalization has some drawbacks and doesn't even cover it all. :heehee:

[CaptLex]

PS: A goody for the FtMs. According to another study the hormones increase your (male) spatial ability performance, and leave the (female) verbal fluency untouched, whereas for the MtFs nothing changes ;)
Oh cool . . . does that mean I can do math now? It'll be like when the Wizard gave the Scarecrow some brains. :D

[Marla S]

Oh cool . . . does that mean I can do math now?

NOOOOOO !!! You won't automatically be able to calculate the volume of a cuboid, but you will be able to rotate it in your mind and make an educated guess.:D

[Marla S]

This study claims that in prior studies "All these transsexuals had received cross-sex hormone treatment before their brains were studied." That's false ...
Could that be a misinterpretation by you ?
I read that paragraph a bit different.
They write:
"A few studies on brain structure in transsexuals have been conducted in post-mortem tissue. [...] . All these transsexuals had received cross-sex hormone treatment before their brains were studied."

My understanding of this is: The prior post mortem studies didn't include transsexuals without cross-sex hormone treatment, hence there is no control for the effect of the hormone treatment for the individual (Question of cause and effect).

This becomes evident from the cited papers too.

Why should they cite themselves (Gooren is co-author of all three respective papers) in a misleading or even wrong way anyway ?

They just did what was suggested in the other paper.

If their results are of any significance ? ... time will tell.

@Agenda science
It's possible, I am not I the position to judge this.
There are amendments concerning the legal status of transsexuals in the pipeline of different European countries, in addition to general laws against discrimination, but the Netherlands are not known to be very restrictive or biased.


This study also ignores that there were several types of controls in the prior studies, including cisgendered people that had received cross-sex hormone treatment (because of various medical conditions). The controls on cross-sex HRT who were not transgendered did not display results similar to those found in the transgendered subjects.
Which is probably is due to the doses (high vs. low dose HRT) and the aim. Non TG patients are usually treated not to alter the sexual characteristics but to maintain them.

[Marla S]

(and I've spoken with other people with scientific training that reached the same conclusion).
This means what ?

At least one of the relevant studies contains misleading statements.
That would be ?


I have figured out the discrepancy. They are not counting the person who had life long transgendered feelings as a "transsexual" - after all, that patient hadn't ever undergone sex reassignment, so they weren't a real transsexual. :rolleyes:

Where is the problem, if their usage and definiton of the term transsexual is consistant, and it is. (Self-definition and an external view on the medical status shouldn't be confused. This brings in an unnecessary emotional load).
I think the discrepancy is the assumption that a change in volume is accompanied by a change of the neuron density. Neither the one nor the other paper really draws that conclusion.


ibid.
The development of high resolution imaging techniques may allow in vivo volume measurements of particular brain areas in much larger groups of transsexuals, which could extend our findings in the distant future. Although brain imaging proved to be useful in visualizing [e.g. septo-hypothalamic brain injuries leading to hypersexuality or altered sexual preference (9, 10)], precise neuroanatomical delineation of small brain structures such as the BSTc or neuronal counts are, at present, not possible using such techniques.
They did in vivo measurements, extended their findings, and have been well aware that they can't directly compare neuroncount and volume.
So it is almost impossible that these papers contradict each other, though I have to agree that the specualtions on the causes for the effects measured in the papers could follow a more clear path. That seems to be a bit selected.

But again: Why should an author be 'deliberately disingenuous' towards himself ? But if. How can you be sure then that the 2000 paper is of any significance ?

IMO terms like 'deliberately disingenuous' shouldn't be used by scientists anyway. There are only very few cases in history of natural sciences when it could have been appropriate.