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.
The sex hormone testosterone exerts a substantial influence on human behaviour and cognition. Previous studies have shown that testosterone has a particular influence on verbal fluency. But these investigations (which due to ethical reasons are mostly observational studies or one-off hormone administrations) have been limited in what they can show, as it has been impossible to follow the direct effect of the hormone on the brain structure.
The researchers, from Vienna and Amsterdam, worked with 18 female-to-male subjects (27.6 ±6.4 years), before and during testosterone treatment. The subjects underwent MRI brain scans before and after 4 weeks of the testosterone administration. The results showed that with testosterone treatment the volume of grey matter decreased in two specific regions of the brain, the Broca’s and Wernicke’s areas, which are mainly responsible for language processing. At the same time, the neuronal pathway (white matter) connecting these two regions via the extreme capsule got stronger.
‘It is well-known that language development differs between girls and boys and that this is related to gender-related differences in brain maturation. However, 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.’
What we know is that male versus female sex hormones have differentiating effects on the brain and behavior that comes out of it. It wouldn’t be too hard to come to the conclusion that men and women value different things.
Additionally, a study on fathers (h/t trp).
The birth of a child leaves its mark on the brain. Most investigations of these changes have focused on mothers, but scientists have recently begun looking more closely at fathers. Neural circuits that support parental behaviors appear more robust in moms a few weeks after the baby is born, whereas in dads the growth can take several months.
A study in Social Neuroscience analyzed 16 dads several weeks after their baby’s birth and again a few months later. At each check, the researchers administered a multiple-choice test to check for signs of depression and used MRI to image the brain. Compared with the earlier scans, MRI at three to four months postpartum showed growth in the hypothalamus, amygdala and other regions that regulate emotion, motivation and decision making. Furthermore, dads with more growth in these brain areas were less likely to show depressive symptoms, says first author Pilyoung Kim, who directs the Family and Child Neuroscience Lab at the University of Denver.
A 2014 behavioral study of expectant fathers showed that midpregnancy ultrasound imaging was a “magic moment” in the dads’ emerging connection with their baby. Yet the emotional bond was different than it is in expectant moms. Instead of thinking about cuddling or feeding the baby, dads-to-be focused on the future: they imagined saving money for a college fund or walking down the aisle at their daughter’s wedding.
Babies change fathers on a physiological level to become more relationship oriented. Also,
Both parent changes versus sex specific changes. Very interesting stuff.