Transition in Transgender: Therapy induced changes in brain and behavior

跨性别者对自己的生理性别感到不适，希望生活并被接受为另一性别的成员。在过去的几年里，公众和媒体越来越意识到变性问题。受影响的人数比以前想象的要多，他们往往面临严重的歧视，并有可能身心健康不佳。近年来，越来越多的神经影像学研究探讨了跨性别者的结构和功能相关性，报告了跨性别女性的女性化迹象，以及跨性别男性的男性化迹象，在几个性别双态的大脑结构和功能过程中。然而，证据仍然稀少，特别是关于在激素治疗过程中大脑结构和功能的可塑性变化。此外，大多数研究都面临着一些方法上的问题，如样本量小，缺乏足够的对照组，以及没有直接比较transmen和transwomen，只是举几个例子。因此，本项目遵循纵向方法来量化交叉激素治疗对大脑和行为的影响，测量大脑结构，以及激素治疗后6个月内的脑功能。接下来的精神病理学评估和问卷调查数据的压力，情绪和主观幸福感以及生活质量，我们打算衡量行为和神经相关性的两个范例评估声音性别和面孔性别的感知，继续但也扩大了我们前面的数据，以表征基本的性别和自我相关的听觉和视觉过程。此外，我们将测试在人类大脑中的神经生物学性别连续统的假设，质疑二元性别概念化的有效性。基于功能连接和问卷数据，我们将应用基于数据的机器学习算法，将每个参与者分配到他/她的性别/性别，以分类主观经验的心理性别，而不考虑生物性别。由于我们成功地将其应用于现有的数据集，因此我们努力在新样本中对我们的发现进行交叉验证。通过纵向数据，我们将进一步检验这一假设，即激素治疗可能会导致分类准确性降低，这是由于治疗引起的他们所追求的性别认同方向的变化。我们希望，这种精确的性别认同生物行为标记可能会增加跨性别领域的临床和社会相关知识。

Transgender individuals are in discomfort with their biological sex and wish to live and be accepted as a member of the other sex. In the last few years the public and media have become more aware of transgender issues. The number of those affected is higher than previously thought, and they often face severe discrimination and are at risk for poor mental and physical health. Many transgender individuals request for cross-sex hormonal treatment and gender confirmation surgery.In recent years, a growing number of neuroimaging studies have inquired into structural and functional correlates of transgender, reporting signs of feminisation in transwomen, and signs of masculinisation in transmen in several sexually dimorphic brain structures as well as functional processes. However, evidence is still sparse especially concerning plastic brain changes in structure and function in the course of hormonal therapy. Furthermore, most studies are confronted with several methodological problems, such as small sample sizes, the lack of adequate control groups as well as no direct comparison between transmen and transwomen, just to name a few.This project hence follows a longitudinal approach to quantify the effects of cross-hormone therapy on brain and behavior, measuring brain structure, as well as brain function over a time period of 6 months following hormone therapy. Next to psychopathological assessments and questionnaire data on stress, emotion and subjective well-being as well as quality of life, we intend to measure behavioral and neural correlates in two paradigms assessing voice gender and face gender perception, continuing but also expanding our preceding data, to characterize basic gender and self-related auditory and visual processes. Furthermore, we will test the hypothesis of a neurobiological gender continuum within the human brain, questioning the validity of a binary gender conceptualization. Based on functional connectivity and questionnaire data we will apply data-based machine learning algorithms naive to the assignment of each participant to his/her gender/sex to classify the subjectively experienced, psychological gender, irrespective of the biological sex. Since we successfully applied this to our already existing data set, we strive for a cross validation of our findings in a new sample. With the longitudinal data we will further test the hypothesis, that hormonal treatment may lead to a reduction in classification accuracy due to therapy-induced changes in direction of their aspired gender identity. We hope, that such precise bio-behavioral markers for gender identity might add clinically and societally relevant knowledge in the field of transgender.