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VanderLaan DP, Skorska MN, Peragine DE, Coome LA. Carving the Biodevelopment of Same-Sex Sexual Orientation at Its Joints. ARCHIVES OF SEXUAL BEHAVIOR 2023; 52:2939-2962. [PMID: 35960401 DOI: 10.1007/s10508-022-02360-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/30/2022] [Accepted: 06/04/2022] [Indexed: 06/15/2023]
Abstract
Sexual orientation is a core aspect of human experience and understanding its development is fundamental to psychology as a scientific discipline. Biological perspectives have played an important role in uncovering the processes that contribute to sexual orientation development. Research in this field has relied on a variety of populations, including community, clinical, and cross-cultural samples, and has commonly focused on female gynephilia (i.e., female sexual attraction to adult females) and male androphilia (i.e., male sexual attraction to adult males). Genetic, hormonal, and immunological processes all appear to influence sexual orientation. Consistent with biological perspectives, there are sexual orientation differences in brain development and evidence indicates that similar biological influences apply across cultures. An outstanding question in the field is whether the hypothesized biological influences are all part of the same process or represent different developmental pathways leading to same-sex sexual orientation. Some studies indicate that same-sex sexually oriented people can be divided into subgroups who likely experienced different biological influences. Consideration of gender expression in addition to sexual orientation might help delineate such subgroups. Thus, future research on the possible existence of such subgroups could prove to be valuable for uncovering the biological development of sexual orientation. Recommendations for such future research are discussed.
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Affiliation(s)
- Doug P VanderLaan
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada.
- Child and Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, Canada.
| | - Malvina N Skorska
- Child and Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Diana E Peragine
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
| | - Lindsay A Coome
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
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2
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Ziogas A, Mokros A, Kawohl W, de Bardeci M, Olbrich I, Habermeyer B, Habermeyer E, Olbrich S. Deep Learning in the Identification of Electroencephalogram Sources Associated with Sexual Orientation. Neuropsychobiology 2023; 82:234-245. [PMID: 37369190 DOI: 10.1159/000530931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 04/21/2023] [Indexed: 06/29/2023]
Abstract
INTRODUCTION It is unclear if sexual orientation is a biological trait that has neurofunctional footprints. With deep learning, the power to classify biological datasets without an a priori selection of features has increased by magnitudes. The aim of this study was to correctly classify resting-state electroencephalogram (EEG) data from males with different sexual orientation using deep learning and to explore techniques to identify the learned distinguishing features. METHODS Three cohorts (homosexual men, heterosexual men, and a mixed sex cohort), one pretrained network on sex classification, and one newly trained network for sexual orientation classification were used to classify sex. Further, Grad-CAM methodology and source localization were used to identify the spatiotemporal patterns that were used for differentiation by the networks. RESULTS Using a pretrained network for classification of males and females, no differences existed between classification of homosexual and heterosexual males. The newly trained network was able, however, to correctly classify the cohorts with a total accuracy of 83%. The retrograde activation using Grad-CAM technology yielded distinctive functional EEG patterns in the Brodmann area 40 and 1 when combined with Fourier analysis and a source localization. DISCUSSION This study shows that electrophysiological trait markers of male sexual orientation can be identified using deep learning. These patterns are different from the differentiating signatures of males and females in a resting-state EEG.
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Affiliation(s)
- Anastasios Ziogas
- Department of Forensic Psychiatry, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | | | - Wolfram Kawohl
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
- Clienia Schlössli AG, Oetwil am See, Switzerland
| | - Mateo de Bardeci
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | | | | | - Elmar Habermeyer
- Department of Forensic Psychiatry, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - Sebastian Olbrich
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
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3
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Clemens B, Lefort-Besnard J, Ritter C, Smith E, Votinov M, Derntl B, Habel U, Bzdok D. Accurate machine learning prediction of sexual orientation based on brain morphology and intrinsic functional connectivity. Cereb Cortex 2023; 33:4013-4025. [PMID: 36104854 PMCID: PMC10068286 DOI: 10.1093/cercor/bhac323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Sexual orientation in humans represents a multilevel construct that is grounded in both neurobiological and environmental factors. OBJECTIVE Here, we bring to bear a machine learning approach to predict sexual orientation from gray matter volumes (GMVs) or resting-state functional connectivity (RSFC) in a cohort of 45 heterosexual and 41 homosexual participants. METHODS In both brain assessments, we used penalized logistic regression models and nonparametric permutation. RESULTS We found an average accuracy of 62% (±6.72) for predicting sexual orientation based on GMV and an average predictive accuracy of 92% (±9.89) using RSFC. Regions in the precentral gyrus, precuneus and the prefrontal cortex were significantly informative for distinguishing heterosexual from homosexual participants in both the GMV and RSFC settings. CONCLUSIONS These results indicate that, aside from self-reports, RSFC offers neurobiological information valuable for highly accurate prediction of sexual orientation. We demonstrate for the first time that sexual orientation is reflected in specific patterns of RSFC, which enable personalized, brain-based predictions of this highly complex human trait. While these results are preliminary, our neurobiologically based prediction framework illustrates the great value and potential of RSFC for revealing biologically meaningful and generalizable predictive patterns in the human brain.
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Affiliation(s)
- Benjamin Clemens
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany
- Research Center Jülich, Institute of Neuroscience and Medicine: JARA-Institute Brain Structure Function Relationship (INM 10), Wilhelm-Johnen-Strase, 52428 Jülich, Germany
| | | | - Christoph Ritter
- Interdisciplinary Center for Clinical Research (IZKF), RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany
| | - Elke Smith
- Biological Psychology, Department of Psychology, University of Cologne, Bernhard-Feilchenfeld-Str. 11, 50969 Cologne, Germany
| | - Mikhail Votinov
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany
- Research Center Jülich, Institute of Neuroscience and Medicine: JARA-Institute Brain Structure Function Relationship (INM 10), Wilhelm-Johnen-Strase, 52428 Jülich, Germany
| | - Birgit Derntl
- Department of Psychiatry and Psychotherapy, University of Tübingen, Calwerst. 14, 72076 Tübingen, Germany
- Werner Reichardt Center for Integrative Neuroscience (CIN), University of Tübingen, Otfried-Müller-Str. 25, 72076 Tübingen, Germany
| | - Ute Habel
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany
- Research Center Jülich, Institute of Neuroscience and Medicine: JARA-Institute Brain Structure Function Relationship (INM 10), Wilhelm-Johnen-Strase, 52428 Jülich, Germany
| | - Danilo Bzdok
- McConnell Brain Imaging Centre, McGill University, 3801 University Rue, Montreal Quebec H3A 2B4, Canada
- Department of Biomedical Engineering, McGill University, 3775 University Rue, Montreal Quebec H3A 2B4, Canada
- Faculty of Medicine, Montreal Neurological Institute (MNI) and Hospital, McGill University, 3801 University Rue, Montreal Quebec H3A 2B4, Canada
- Mila–Quebec Artificial Intelligence Institute, 6666 Rue St-Urbain #200, Montreal Quebec H2S 3H1, Canada
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Tasos E. To What Extent are Prenatal Androgens Involved in the Development of Male Homosexuality in Humans? JOURNAL OF HOMOSEXUALITY 2022; 69:1928-1963. [PMID: 34080960 DOI: 10.1080/00918369.2021.1933792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Endocrine variations, including possibly reduced exposure to androgens, may contribute to the development of male homosexuality, with animal models demonstrating same-sex mate preference with altered exposure during prenatal or early postnatal development. As similar studies in humans are impossible, indirect physical and cognitive measures of androgen exposure are used. Some studies suggest that physical measures affected by prenatal androgens, including the index-to-ring finger ratio, growth indices, and facial structure, are more "feminine" in gay men. Gay men also exhibit significant childhood gender non-conformity and a "feminized" anatomical and functional brain pattern in sexual arousal, as well as domains such as language, visuospatial skills and hemispheric relationships. However, many of these results are equivocal and may be confounded by other factors. Research has also been hampered by inconsistencies in the reporting of sexual orientation and the potentially unrepresentative populations of gay men studied, while additional complexities pertaining to gender conformity and sexual role may also influence results.
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Affiliation(s)
- Emmanouil Tasos
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
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5
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Jain S, Rana M. Alternative Sexual Orientation in Humans: What Is Known and What Needs to Be Known Further. JOURNAL OF HOMOSEXUALITY 2022; 69:1004-1029. [PMID: 33788667 DOI: 10.1080/00918369.2021.1898805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Since the 20th century, multiple studies have linked the variations in human sexual orientation, from heterosexuality to bisexuality or homosexuality, to a wide range of biological factors. However, a clear mechanism that leads to the development of these variations has not been established yet. This review consolidates various comprehensive studies on the possible biological factors in the fields of genetics, epigenetics, uterine environment, hormones, neuroanatomy, and neurobiology that lead to these variations. One intriguing question that 'homosexuality phenotype' faces is its ability to avoid elimination by Darwinian selection. This review tries to explain why natural selection is not eliminating the genetic factors associated with homosexuality even at the cost of the evolutionary fitness of homosexual individuals. Studies supporting certain strong candidates for alternative sexual orientation (ASO) are highlighted, which can become new research avenues for investigators in this field. Further, a novel speculation is proposed that might be contributing to the development of variation in human sexuality.
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Affiliation(s)
- Sidhant Jain
- Department of Zoology, University of Delhi, Delhi, India
| | - Meenakshi Rana
- Department of Zoology, University of Delhi, Delhi, India
- Dyal Singh College, University of Delhi, Delhi, India
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Nicholson AA, Siegel M, Wolf J, Narikuzhy S, Roth SL, Hatchard T, Lanius RA, Schneider M, Lloyd CS, McKinnon MC, Heber A, Smith P, Lueger-Schuster B. A systematic review of the neural correlates of sexual minority stress: towards an intersectional minority mosaic framework with implications for a future research agenda. Eur J Psychotraumatol 2022; 13:2002572. [PMID: 35251527 PMCID: PMC8890555 DOI: 10.1080/20008198.2021.2002572] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/18/2021] [Accepted: 10/29/2021] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Systemic oppression, particularly towards sexual minorities, continues to be deeply rooted in the bedrock of many societies globally. Experiences with minority stressors (e.g. discrimination, hate-crimes, internalized homonegativity, rejection sensitivity, and microaggressions or everyday indignities) have been consistently linked to adverse mental health outcomes. Elucidating the neural adaptations associated with minority stress exposure will be critical for furthering our understanding of how sexual minorities become disproportionately affected by mental health burdens. METHODS Following PRISMA-guidelines, we systematically reviewed published neuroimaging studies that compared neural dynamics among sexual minority and heterosexual populations, aggregating information pertaining to any measurement of minority stress and relevant clinical phenomena. RESULTS Only 1 of 13 studies eligible for inclusion examined minority stress directly, where all other studies focused on investigating the neurobiological basis of sexual orientation. In our narrative synthesis, we highlight important themes that suggest minority stress exposure may be associated with decreased activation and functional connectivity within the default-mode network (related to the sense-of-self and social cognition), and summarize preliminary evidence related to aberrant neural dynamics within the salience network (involved in threat detection and fear processing) and the central executive network (involved in executive functioning and emotion regulation). Importantly, this parallels neural adaptations commonly observed among individuals with posttraumatic stress disorder (PTSD) in the aftermath of trauma and supports the inclusion of insidious forms of trauma related to minority stress within models of PTSD. CONCLUSIONS Taken together, minority stress may have several shared neuropsychological pathways with PTSD and stress-related disorders. Here, we outline a detailed research agenda that provides an overview of literature linking sexual minority stress to PTSD and insidious trauma, moral affect (including shame and guilt), and mental health risk/resiliency, in addition to racial, ethnic, and gender related minority stress. Finally, we propose a novel minority mosaic framework designed to inform future directions of minority stress neuroimaging research from an intersectional lens.
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Affiliation(s)
- Andrew A. Nicholson
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Canada
- Department of Cognition, Emotion, and Methods in Psychology, University of Vienna, Vienna, Austria
- Department of Medical Biophysics, Western University, London, Canada
- Homewood Research Institute, Guelph, Canada
| | - Magdalena Siegel
- Department of Developmental and Educational Psychology, University of Vienna, Vienna, Austria
- Department of Public Health, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
| | - Jakub Wolf
- Department of Cognition, Emotion, and Methods in Psychology, University of Vienna, Vienna, Austria
| | - Sandhya Narikuzhy
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Canada
| | - Sophia L. Roth
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Canada
| | - Taylor Hatchard
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Canada
| | - Ruth A. Lanius
- Department of Psychiatry, Western University, London, Canada
| | - Maiko Schneider
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Canada
| | | | - Margaret C. McKinnon
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Canada
- Homewood Research Institute, Guelph, Canada
| | | | - Patrick Smith
- The Centre of Excellence for PTSD, Royal Ottawa Hospital, Ottawa, Canada
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Ma Q, Shi X, Chen G, Song F, Liu F, Zheng H, Shi Y, Cai DC. HIV-Associated Structural and Functional Brain Alterations in Homosexual Males. Front Neurol 2022; 12:757374. [PMID: 35095719 PMCID: PMC8796998 DOI: 10.3389/fneur.2021.757374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: Neuroimaging elucidations have shown structural and functional brain alterations in HIV-infected (HIV+) individuals when compared to HIV-negative (HIV–) controls. However, HIV− groups used in previous studies were not specifically considered for sexual orientation, which also affects the brain structures and functions. The current study aimed to characterize the brain alterations associated with HIV infection while controlling for sexual orientation. Methods: Forty-three HIV+ and 40 HIV– homosexual men (HoM) were recruited and underwent resting-state MRI scanning. Group differences in gray matter volume (GMV) were assessed using a voxel-based morphometry analysis. Brain regions with the altered GMV in the HIV+ HoM group were then taken as regions of interest in a seed-based analysis to identify altered functional connectivity. Furthermore, the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity values were compared between the two groups to evaluate the HIV-associated functional abnormalities in local brain regions. Results: HIV+ HoM showed significantly increased GMV in the bilateral parahippocampal gyrus and amygdala, and decreased GMV in the right inferior cerebellum, compared with the HIV– HoM. The brain regions with increased GMV were hyper-connected with the left superior cerebellum, right lingual gyrus, and left precuneus in the HIV+ HoM. Moreover, the ALFF values of the right fusiform gyrus, and left parahippocampal gyrus were increased in the HIV+ HoM. The regional homogeneity values of the right anterior cingulate and paracingulate gyri, and left superior cerebellum were decreased in the HIV+ HoM. Conclusion: When the study population was restricted to HoM, HIV+ individuals exhibited structural alterations in the limbic system and cerebellum, and functional abnormalities in the limbic, cerebellum, and visual network. These findings complement the existing knowledge on the HIV-associated neurocognitive impairment from the previous neuroimaging studies by controlling for the potential confounding factor, sexual orientation. Future studies on brain alternations with the exclusion of related factors like sexual orientation are needed to understand the impact of HIV infection on neurocognitive function more accurately.
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Affiliation(s)
- Qiong Ma
- Shanghai Institute of Medical Imaging, Fudan University, Shanghai, China
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Xiudong Shi
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Guochao Chen
- Shanghai Institute of Medical Imaging, Fudan University, Shanghai, China
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Fengxiang Song
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Fengjun Liu
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Huang Zheng
- Shanghai Commercial Sex Worker (CSW) & Man Have Sex With Man (MSM) Center, Shanghai, China
| | - Yuxin Shi
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
- *Correspondence: Yuxin Shi
| | - Dan-Chao Cai
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
- Dan-Chao Cai
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8
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Li H, Fernández-Guasti A, Xu Y, Swaab D. Retracted: Sexual orientation, neuropsychiatric disorders and the neurotransmitters involved. Neurosci Biobehav Rev 2021; 131:479-488. [PMID: 34597715 DOI: 10.1016/j.neubiorev.2021.09.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 08/17/2021] [Accepted: 09/26/2021] [Indexed: 11/26/2022]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor in Chief of Neuroscience and Biobehavioral Reviews after concerns were raised with respect to the phrasing of comparisons drawn between humans and animal models. These comparisons were deemed unsupportable, and thus in the best interests of publication standards the Editor has concluded it is necessary to retract the paper. The authors disagree with the reason for the retraction.
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Affiliation(s)
- Haimei Li
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, PR China; Department of Neuropsychiatric Disorders, Netherlands Institute for Neuroscience, Amsterdam, 1105 BA, the Netherlands
| | | | - Yi Xu
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, PR China; The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou, 310003, PR China; Zhejiang Engineering Center for Mathematical Mental Health, Hangzhou, 310003, PR China; Brain Research Institute of Zhejiang University, Hangzhou, 31003, PR China.
| | - Dick Swaab
- Department of Neuropsychiatric Disorders, Netherlands Institute for Neuroscience, Amsterdam, 1105 BA, the Netherlands.
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Frigerio A, Ballerini L, Valdés Hernández M. Structural, Functional, and Metabolic Brain Differences as a Function of Gender Identity or Sexual Orientation: A Systematic Review of the Human Neuroimaging Literature. ARCHIVES OF SEXUAL BEHAVIOR 2021; 50:3329-3352. [PMID: 33956296 PMCID: PMC8604863 DOI: 10.1007/s10508-021-02005-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 05/05/2023]
Abstract
This review systematically explored structural, functional, and metabolic features of the cisgender brain compared with the transgender brain before hormonal treatment and the heterosexual brain compared to the homosexual brain from the analysis of the neuroimaging literature up to 2018, and identified and discussed subsequent studies published up to March 2021. Our main aim was to help identifying neuroradiological brain features that have been related to human sexuality to contribute to the understanding of the biological elements involved in gender identity and sexual orientation. We analyzed 39 studies on gender identity and 24 on sexual orientation. Our results suggest that some neuroanatomical, neurophysiological, and neurometabolic features in transgender individuals resemble those of their experienced gender despite the majority resembling those from their natal sex. In homosexual individuals the majority resemble those of their same-sex heterosexual population rather than their opposite-sex heterosexual population. However, it is always difficult to interpret findings with noninvasive neuroimaging. Given the gross nature of these measures, it is possible that more differences too subtle to measure with available tools yet contributing to gender identity and sexual orientation could be found. Conflicting results contributed to the difficulty of identifying specific brain features which consistently differ between cisgender and transgender or between heterosexual and homosexual groups. The small number of studies, the small-to-moderate sample size of each study, and the heterogeneity of the investigations made it impossible to meta-analyze all the data extracted. Further studies are necessary to increase the understanding of the neurological substrates of human sexuality.
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Affiliation(s)
- Alberto Frigerio
- Division of Health Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Lucia Ballerini
- Division of Health Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
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Clemens B, Votinov M, Puiu AA, Schüppen A, Hüpen P, Neulen J, Derntl B, Habel U. Replication of Previous Findings? Comparing Gray Matter Volumes in Transgender Individuals with Gender Incongruence and Cisgender Individuals. J Clin Med 2021; 10:1454. [PMID: 33916288 PMCID: PMC8037365 DOI: 10.3390/jcm10071454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/23/2021] [Accepted: 03/29/2021] [Indexed: 01/30/2023] Open
Abstract
The brain structural changes related to gender incongruence (GI) are still poorly understood. Previous studies comparing gray matter volumes (GMV) between cisgender and transgender individuals with GI revealed conflicting results. Leveraging a comprehensive sample of transmen (n = 33), transwomen (n = 33), cismen (n = 24), and ciswomen (n = 25), we employ a region-of-interest (ROI) approach to examine the most frequently reported brain regions showing GMV differences between trans- and cisgender individuals. The primary aim is to replicate previous findings and identify anatomical regions which differ between transgender individuals with GI and cisgender individuals. On the basis of a comprehensive literature search, we selected a set of ROIs (thalamus, putamen, cerebellum, angular gyrus, precentral gyrus) for which differences between cis- and transgender groups have been previously observed. The putamen was the only region showing significant GMV differences between cis- and transgender, across previous studies and the present study. We observed increased GMV in the putamen for transwomen compared to both transmen and ciswomen and for all transgender participants compared to all cisgender participants. Such a pattern of neuroanatomical differences corroborates the large majority of previous studies. This potential replication of previous findings and the known involvement of the putamen in cognitive processes related to body representations and the creation of the own body image indicate the relevance of this region for GI and its potential as a structural biomarker for GI.
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Affiliation(s)
- Benjamin Clemens
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany; (M.V.); (A.A.P.); (P.H.); (U.H.)
- Institute of Neuroscience and Medicine 10, Research Centre Jülich, 52428 Jülich, Germany
| | - Mikhail Votinov
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany; (M.V.); (A.A.P.); (P.H.); (U.H.)
- Institute of Neuroscience and Medicine 10, Research Centre Jülich, 52428 Jülich, Germany
| | - Andrei Alexandru Puiu
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany; (M.V.); (A.A.P.); (P.H.); (U.H.)
- Institute of Neuroscience and Medicine 10, Research Centre Jülich, 52428 Jülich, Germany
| | - Andre Schüppen
- Interdisciplinary Center for Clinical Research (IZKF), Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany;
- Division for Clinical and Cognitive Sciences, Department of Neurology, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany
| | - Philippa Hüpen
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany; (M.V.); (A.A.P.); (P.H.); (U.H.)
- Institute of Neuroscience and Medicine 10, Research Centre Jülich, 52428 Jülich, Germany
| | - Josef Neulen
- Department of Gynecological Endocrinology and Reproductive Medicine, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany;
| | - Birgit Derntl
- Department of Psychiatry and Psychotherapy, University of Tübingen, 72074 Tübingen, Germany;
- LEAD Graduate School and Research Network, University of Tübingen, 72072 Tübingen, Germany
| | - Ute Habel
- Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen University, 52062 Aachen, Germany; (M.V.); (A.A.P.); (P.H.); (U.H.)
- Institute of Neuroscience and Medicine 10, Research Centre Jülich, 52428 Jülich, Germany
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Abstract
Biological sex differences in brain function and structure are reliably associated with several cortico-subcortical brain regions. While sexual orientation (hetero- versus homosexuality) has been similarly linked to functional differences in several phylogenetically-old brain areas, the research on morphological brain phenotypes associated with sexual orientation is far from conclusive. We examined potential cerebral structural differences linked to sexual orientation in a group of 74 participants, including 37 men (21 homosexual) and 37 women (19 homosexual) using voxel-based morphometry (VBM). Gray matter volumes (GMV) were compared with respect to sexual orientation and biological sex across the entire sample using full factorial designs controlling for total intracranial volume, age, handedness, and education. We observed a significant effect of sexual orientation for the thalamus and precentral gyrus, with more GMV in heterosexual versus homosexual individuals, and for the putamen, with more GMV in homosexual + than heterosexual individuals. We found significant interactions between biological sex and sexual orientation, indicating that the significant effect for the putamen cluster was driven by homosexual women, whereas heterosexual women had increased precentral gyrus GMV. Heterosexual men exhibited more GMV in the thalamus than homosexual men. This study shows that sexual orientation is reflected in brain structure characteristics and that these differ between the sexes. The results emphasize the need to include or control for potential effects of participants' sexual orientation in neuroimaging studies. Furthermore, our findings provide important new insights into the brain morphology underlying sexual orientation and likely have important implications for understanding brain functions and behavior.
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12
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Abé C, Lebedev A, Zhang R, Jonsson L, Bergen SE, Ingvar M, Landén M, Rahman Q. Cross-sex shifts in two brain imaging phenotypes and their relation to polygenic scores for same-sex sexual behavior: A study of 18,645 individuals from the UK Biobank. Hum Brain Mapp 2021; 42:2292-2304. [PMID: 33635603 PMCID: PMC8046142 DOI: 10.1002/hbm.25370] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/07/2021] [Accepted: 02/04/2021] [Indexed: 12/13/2022] Open
Abstract
Genetic and hormonal factors have been suggested to influence human sexual orientation. Previous studied proposed brain differences related to sexual orientation and that these follow cross-sex shifted patterns. However, the neurobiological correlates of sexual orientation and how genetic factors relate to brain structural variation remains largely unexplored. Using the largest neuroimaging-genetics dataset available on same-sex sexual behavior (SSB) (n = 18,645), we employed a data-driven multivariate classification algorithm (PLS) on magnetic resonance imaging data from two imaging modalities to extract brain covariance patterns related to sex. Through analyses of latent variables, we tested for SSB-related cross-sex shifts in such patterns. Using genotype data, polygenic scores reflecting the genetic predisposition for SSB were computed and tested for associations with neuroimaging outcomes. Patterns important for classifying between males and females were less pronounced in non-heterosexuals. Predominantly in non-heterosexual females, multivariate brain patterns as represented by latent variables were shifted toward the opposite sex. Complementary univariate analyses revealed region specific SSB-related differences in both males and females. Polygenic scores for SSB were associated with volume of lateral occipital and temporo-occipital cortices. The present large-scale study demonstrates multivariate neuroanatomical correlates of SSB, and tentatively suggests that genetic factors related to SSB may contribute to structural variation in certain brain structures. These findings support a neurobiological basis to the differences in human sexuality.
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Affiliation(s)
- Christoph Abé
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Alexander Lebedev
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ruyue Zhang
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Lina Jonsson
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sarah E Bergen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Martin Ingvar
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mikael Landén
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Qazi Rahman
- Department of Psychology, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
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13
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Folkierska-Żukowska M, Rahman Q, Marchewka A, Wypych M, Droździel D, Sokołowski A, Dragan WŁ. Male sexual orientation, gender nonconformity, and neural activity during mental rotations: an fMRI study. Sci Rep 2020; 10:18709. [PMID: 33127919 PMCID: PMC7599322 DOI: 10.1038/s41598-020-74886-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 10/08/2020] [Indexed: 12/22/2022] Open
Abstract
The cross-sex shift hypothesis predicts that gay men should perform more like heterosexual women on important neurocognitive tasks on which men score higher than women, such as mental rotation. Studies also suggest sex differences exist in the neural correlates of mental rotation. However, no studies have taken sexual orientation into account or considered within-group variation attributable to recalled gender nonconformity (a developmental trait reliably associated with human nonheterosexuality). We quantified the neural correlates of mental rotation by comparing two groups of gay men, gender conforming (n = 23) and gender nonconforming (n = 23), to gender conforming heterosexual men (n = 22) and women (n = 22). We observed a sex difference between heterosexual men and women in the premotor cortex/supplementary motor cortex and left medial superior frontal gyrus. We also observed a sex difference as well as a cross-sex shift in gay men who recalled being gender nonconforming as children in the right superior frontal gyrus, right angular gyrus, right amygdala/parahippocampal gyrus, and bilaterally in the middle temporal gyrus and precuneus. Thus, cross-sex shifts may be associated with underlying developmental factors which are associated with sexual orientation (such as gender nonconformity). The results also suggest that gay men should not be studied as a homogenous group.
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Affiliation(s)
| | - Qazi Rahman
- Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Artur Marchewka
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Marek Wypych
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Dawid Droździel
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Warsaw, Poland
| | - Andrzej Sokołowski
- Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
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14
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Wang D, Han L, Xi C, Xu Y, Lai J, Lu S, Huang M, Hu J, Wei N, Xu W, Zhou W, Lu Q, He H, Hu S. Interactive effects of gender and sexual orientation on cortical thickness, surface area and gray matter volume: a structural brain MRI study. Quant Imaging Med Surg 2020; 10:835-846. [PMID: 32355647 DOI: 10.21037/qims.2020.03.07] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Background Testosterone is thought to play a crucial role in sexual differentiation of the brain, and sexual orientation is programmed into our brain structures even when we are still fetuses. Although gender and sexual orientation differences have been shown respectively in many brain structures, the mechanism underlying the sexual differentiation of the brain is still unknown. The study is to investigate the interactive effects of gender and sexual orientation on cerebral structures in homosexual and heterosexual people. Methods Sexual orientation was evaluated by the Kinsey scale. We collected structural magnetic resonance image (MRI) data of local cortical thickness, surface area, and gray matter volume in all the subjects (29 homosexual and 29 heterosexual men, 17 homosexual and 17 heterosexual women). Statistical maps were generated using a general linear model (GLM) using FreeSurfer's Query, Design, Estimate, Contrast (QDEC) interface. We had sexual orientation and gender as 2 discrete factors with 2 levels, allowing for the generation of the interaction between sexual orientation and gender: homosexual women and heterosexual men versus heterosexual women and homosexual men. Coordinates were in Talairach space. All the cluster sizes were calculated with a P value of 0.01. Results Results revealed interactions concerning the area and gray matter volume between the factors of sexual orientation and gender. Regarding the thickness, an interaction was not found in any regions of the clusters. Regarding the area, an interaction was found in region of left middle temporal lobe, inferior temporal lobe, lateral occipital lobe, fusiform [(-58.1, -38.6, -14.7), maximum vertex-wise (MV) log10(P) =3.30, cluster size (CS) =1,286.90 mm2], and left rostral middle frontal lobe, pars opercularis, caudal middle frontal lobe [(-37.3, 23.6, 24.8), MV log10(P) =2.92, CS =1,194.40 mm2]. Regarding the gray matter volume, an interaction was found in the region of the left pars opercularis (inferior frontal gyrus) [(-42.9, 6.3, 18.5), MV log10(P) =1.31, CS =526.79 mm2]. Conclusions The present study extends our understandings of how structural features differ in homosexual men, heterosexual men, homosexual women, and heterosexual women. Furthermore, it highlights the interactions between sexual orientation and gender in the left inferior frontal gyrus, bilateral temporal lobe, and the right rostral anterior cingulate cortex, which are suggested to play a critical role in the sexual differentiation of the human brain.
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Affiliation(s)
- Dandan Wang
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Lu Han
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Hangzhou 310027, China
| | - Caixi Xi
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Yi Xu
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Jianbo Lai
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Shaojia Lu
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Manli Huang
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Jianbo Hu
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Ning Wei
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Weijuan Xu
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Weihua Zhou
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Qiaoqiao Lu
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
| | - Hongjian He
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Hangzhou 310027, China
| | - Shaohua Hu
- Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.,The Key Laboratory of Mental Disorder Management in Zhejiang Province, Hangzhou 310003, China
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15
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Pletzer B. Sex Hormones and Gender Role Relate to Gray Matter Volumes in Sexually Dimorphic Brain Areas. Front Neurosci 2019; 13:592. [PMID: 31275099 PMCID: PMC6591487 DOI: 10.3389/fnins.2019.00592] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/23/2019] [Indexed: 12/21/2022] Open
Abstract
The present study investigates the relationship of circulating sex hormone levels and gender role to gray matter volumes in sexually dimorphic brain areas and explores, whether these relationships are modulated by biological sex (as assigned at birth based on sexual anatomy) or oral contraceptive (OC) use. It was hypothesized that testosterone and masculinity relate positively to gray matter volumes in areas that are typically larger in men, like the hippocampus or cerebellum, while estradiol/progesterone and femininity relate positively to gray matter volumes in the frontal cortex. To that end, high resolution structural MRI scans, sex hormone levels and gender role self-assessments were obtained in a large sample 89 men, 89 naturally cycling (NC) women, and 60 OC users. Men showed larger regional gray matter volumes than women in the cerebellum and bilateral clusters spanning the putamen and parts of the hippocampi/parahippocampi and fusiform gyri. In accordance with our hypotheses, a significant positive association of testosterone to hippocampal volumes was observed in women irrespective of OC use. Participant's self-reported femininity was significantly positively associated with gray matter volumes in the left middle frontal gyrus (MFG) in men. In addition several differences between OC-users and NC women were identified.
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Affiliation(s)
- Belinda Pletzer
- Department of Psychology, University of Salzburg, Salzburg, Austria
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
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16
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Manzouri A, Savic I. Possible Neurobiological Underpinnings of Homosexuality and Gender Dysphoria. Cereb Cortex 2019; 29:2084-2101. [PMID: 30084980 PMCID: PMC6677918 DOI: 10.1093/cercor/bhy090] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/13/2018] [Accepted: 04/03/2018] [Indexed: 01/13/2023] Open
Abstract
Although frequently discussed in terms of sex dimorphism, the neurobiology of sexual orientation and identity is unknown. We report multimodal magnetic resonance imaging data, including cortical thickness (Cth), subcortical volumes, and resting state functional magnetic resonance imaging, from 27 transgender women (TrW), 40 transgender men (TrM), and 80 heterosexual (40 men) and 60 homosexual cisgender controls (30 men). These data show that whereas homosexuality is linked to cerebral sex dimorphism, gender dysphoria primarily involves cerebral networks mediating self-body perception. Among the homosexual cisgender controls, weaker sex dimorphism was found in white matter connections and a partly reversed sex dimorphism in Cth. Similar patterns were detected in transgender persons compared with heterosexual cisgender controls, but the significant clusters disappeared when adding homosexual controls, and correcting for sexual orientation. Instead, both TrW and TrM displayed singular features, showing greater Cth as well as weaker structural and functional connections in the anterior cingulate-precuneus and right occipito-parietal cortex, regions known to process own body perception in the context of self.
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Affiliation(s)
- A Manzouri
- Department of Women’s and Children’s Health, Karolinska Institute and University Hospital, Stockholm, Sweden
| | - I Savic
- Department of Women’s and Children’s Health, Karolinska Institute and University Hospital, Stockholm, Sweden
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
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17
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Manzouri A, Savic I. Multimodal MRI suggests that male homosexuality may be linked to cerebral midline structures. PLoS One 2018; 13:e0203189. [PMID: 30278046 PMCID: PMC6168246 DOI: 10.1371/journal.pone.0203189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 08/01/2018] [Indexed: 01/06/2023] Open
Abstract
The neurobiology of sexual preference is often discussed in terms of cerebral sex dimorphism. Yet, our knowledge about possible cerebral differences between homosexual men (HoM), heterosexual men (HeM) and heterosexual women (HeW) are extremely limited. In the present MRI study, we addressed this issue investigating measures of cerebral anatomy and function, which were previously reported to show sex difference. Specifically, we asked whether there were any signs of sex atypical cerebral dimorphism among HoM, if these were widely distributed (providing substrate for more general 'female' behavioral characteristics among HoM), or restricted to networks involved in self-referential sexual arousal. Cortical thickness (Cth), surface area (SA), subcortical structural volumes, and resting state functional connectivity were compared between 30 (HoM), 35 (HeM) and 38 (HeW). HoM displayed a significantly thicker anterior cingulate cortex (ACC), precuneus, and the left occipito-temporal cortex compared to both control groups. These differences seemed coordinated, since HoM also displayed stronger cortico-cortical covariations between these regions. Furthermore, functional connections within the default mode network, which mediates self- referential processing, and includes the ACC and precuneus were significantly weaker in HoM than HeM and HeW, whereas their functional connectivity between the thalamus and hypothalamus (important nodes for sexual behavior) was stronger. In addition to these singular features, HoM displayed 'female' characteristics, with a similar Cth in the left superior parietal and cuneus cortices as HeW, but different from HeM. These data suggest both singular and sex atypical features and motivate further investigations of cerebral midline structures in relation to male homosexuality.
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Affiliation(s)
- Amirhossein Manzouri
- Department of Women’s and Children’s Health, and Neurology Clinic, Karolinska Institute and Hospital, Stockholm, Sweden
- Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Ivanka Savic
- Department of Women’s and Children’s Health, and Neurology Clinic, Karolinska Institute and Hospital, Stockholm, Sweden
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18
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Abé C, Rahman Q, Långström N, Rydén E, Ingvar M, Landén M. Cortical brain structure and sexual orientation in adult females with bipolar disorder or attention deficit hyperactivity disorder. Brain Behav 2018; 8:e00998. [PMID: 29845776 PMCID: PMC6043709 DOI: 10.1002/brb3.998] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/29/2018] [Accepted: 04/19/2018] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Nonheterosexual individuals have higher risk of psychiatric morbidity. Together with growing evidence for sexual orientation-related brain differences, this raises the concern that sexual orientation may be an important factor to control for in neuroimaging studies of neuropsychiatric disorders. METHODS We studied sexual orientation in adult psychiatric patients with bipolar disorder (BD) or ADHD in a large clinical cohort (N = 154). We compared cortical brain structure in exclusively heterosexual women (HEW, n = 29) with that of nonexclusively heterosexual women (nHEW, n = 37) using surface-based reconstruction techniques provided by FreeSurfer. RESULTS The prevalence of nonheterosexual sexual orientation was tentatively higher than reported in general population samples. Consistent with previously reported cross-sex shifted brain patterns among homosexual individuals, nHEW patients showed significantly larger cortical volumes than HEW in medial occipital brain regions. CONCLUSION We found evidence for a sex-reversed difference in cortical volume among nonheterosexual female patients, which provides insights into the neurobiology of sexual orientation, and may provide the first clues toward a better neurobiological understanding of the association between sexual orientation and mental health. We also suggest that sexual orientation is an important factor to consider in future neuroimaging studies of populations with certain mental health disorders.
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Affiliation(s)
- Christoph Abé
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Qazi Rahman
- Department of Psychology, Institute of Psychiatry, King's College London, London, UK
| | - Niklas Långström
- Department of Neuroscience, Uppsala University, Uppsala, Sweden.,Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Eleonore Rydén
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Martin Ingvar
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mikael Landén
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
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19
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Mohammadi MR, Khaleghi A. Transsexualism: A Different Viewpoint to Brain Changes. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2018; 16:136-143. [PMID: 29739126 PMCID: PMC5953012 DOI: 10.9758/cpn.2018.16.2.136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/12/2018] [Accepted: 02/13/2018] [Indexed: 01/13/2023]
Abstract
Transsexualism refers to a condition or belief which results in gender dysphoria in individuals and makes them insist that their biological gender is different from their psychological and experienced gender. Although the etiology of gender dysphoria (or transsexualism) is still unknown, different neuroimaging studies show that structural and functional changes of the brain result from this sexual incongruence. The question here is whether these reported changes form part of the etiology of transsexualism or themselves result from transsexualism culture, behaviors and lifestyle. Responding to this question can be more precise by consideration of cultural neuroscience concepts, particularly the culture–behavior–brain (CBB) loop model and the interactions between behavior, culture and brain. In this article, we first review the studies on the brain of transgender people and then we will discuss the validity of this claim based on the CBB loop model. In summary, transgender individuals experience change in lifestyle, context of beliefs and concepts and, as a result, their culture and behaviors. Given the close relationship and interaction between culture, behavior and brain, the individual’s brain adapts itself to the new condition (culture) and concepts and starts to alter its function and structure.
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Affiliation(s)
- Mohammad Reza Mohammadi
- Psychiatry & Psychology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Khaleghi
- Psychiatry & Psychology Research Center, Tehran University of Medical Sciences, Tehran, Iran
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20
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Manzouri A, Savic I. Cerebral sex dimorphism and sexual orientation. Hum Brain Mapp 2018; 39:1175-1186. [PMID: 29227002 PMCID: PMC6866632 DOI: 10.1002/hbm.23908] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 11/29/2017] [Accepted: 11/29/2017] [Indexed: 11/08/2022] Open
Abstract
The neurobiology of sexual orientation is frequently discussed in terms of cerebral sex dimorphism (defining both functional and structural sex differences). Yet, the information about possible cerebral differences between sex-matched homo and heterosexual persons is limited, particularly among women. In this multimodal MRI study, we addressed these issues by investigating possible cerebral differences between homo and heterosexual persons, and by asking whether there is any sex difference in this aspect. Measurements of cortical thickness (Cth), subcortical volumes, and functional and structural resting-state connections among 40 heterosexual males (HeM) and 40 heterosexual females (HeF) were compared with those of 30 homosexual males (HoM) and 30 homosexual females (HoF). Congruent with previous reports, sex differences were detected in heterosexual controls with regard to fractional anisotropy (FA), Cth, and several subcortical volumes. Homosexual groups did not display any sex differences in FA values. Furthermore, their functional connectivity was significantly less pronounced in the mesial prefrontal and precuneus regions. In these two particular regions, HoM also displayed thicker cerebral cortex than other groups, whereas HoF did not differ from HeF. In addition, in HoM the parietal Cth showed "sex-reversed" values, not observed in HoF. Homosexual orientation seems associated with a less pronounced sexual differentiation of white matter tracts and a less pronounced functional connectivity of the self-referential networks compared to heterosexual orientation. Analyses of Cth suggest that male and female homosexuality are not simple analogues of each other and that differences from heterosexual controls are more pronounced in HoM.
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Affiliation(s)
- Amirhossein Manzouri
- Department of Women's and Children's Health, and Neurology ClinicKarolinska Institutet and HospitalStickholmSE‐171 76Sweden
| | - Ivanka Savic
- Department of Women's and Children's Health, and Neurology ClinicKarolinska Institutet and HospitalStickholmSE‐171 76Sweden
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21
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Manzouri A, Kosidou K, Savic I. Anatomical and Functional Findings in Female-to-Male Transsexuals: Testing a New Hypothesis. Cereb Cortex 2018; 27:998-1010. [PMID: 26637450 DOI: 10.1093/cercor/bhv278] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Gender dysphoria (GD) is characterized by incongruence between onés gender assigned at birth and the gender that one identifies with. The biological mechanisms of GD are unclear, especially in female-to-male transsexuals (FtM-TR). Here, we investigate whether distinct structural and functional patterns along cerebral midline networks processing own-body perception may constitute a biological correlate. METHOD MRI of functional connectivity, cortical thickness, surface area, and gray matter volume was carried out in 28 female-to-male transsexuals (FtM-TR) and 68 cis-sexual controls (34 male). FtM-TR displayed thicker mid-frontal, precuneal-parietal, and lingual cortex than both male and female controls, whereas, in regions with reported anatomical sex differences among the controls, FtM-TR followed patterns of the gender assigned at their birth. FtM-TR also displayed weaker functional connections from the pregenual anterior cingulate to the insular cortex, and the temporo parietal junction compared with both control groups. Distinct structural and functional pattern in the own-body image network may represent biological markers for the dysphoric own-body perception in transgender individuals.
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Affiliation(s)
- A Manzouri
- Department of Women's and Children's Health and Neurology Clinic, Karolinska Institute and University Hospital, Stockholm, Sweden
| | - K Kosidou
- Gender team, Psychiatry Southwest, Karolinska University Hospital and Center for Epidemiology and Community Medicine, Karolinska Institute, Stockholm, Sweden
| | - I Savic
- Department of Women's and Children's Health and Neurology Clinic, Karolinska Institute and University Hospital, Stockholm, Sweden
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22
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Burke SM, Manzouri AH, Savic I. Structural connections in the brain in relation to gender identity and sexual orientation. Sci Rep 2017; 7:17954. [PMID: 29263327 PMCID: PMC5738422 DOI: 10.1038/s41598-017-17352-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 11/23/2017] [Indexed: 12/22/2022] Open
Abstract
Both transgenderism and homosexuality are facets of human biology, believed to derive from different sexual differentiation of the brain. The two phenomena are, however, fundamentally unalike, despite an increased prevalence of homosexuality among transgender populations. Transgenderism is associated with strong feelings of incongruence between one's physical sex and experienced gender, not reported in homosexual persons. The present study searches to find neural correlates for the respective conditions, using fractional anisotropy (FA) as a measure of white matter connections that has consistently shown sex differences. We compared FA in 40 transgender men (female birth-assigned sex) and 27 transgender women (male birth-assigned sex), with both homosexual (29 male, 30 female) and heterosexual (40 male, 40 female) cisgender controls. Previously reported sex differences in FA were reproduced in cis-heterosexual groups, but were not found among the cis-homosexual groups. After controlling for sexual orientation, the transgender groups showed sex-typical FA-values. The only exception was the right inferior fronto-occipital tract, connecting parietal and frontal brain areas that mediate own body perception. Our findings suggest that the neuroanatomical signature of transgenderism is related to brain areas processing the perception of self and body ownership, whereas homosexuality seems to be associated with less cerebral sexual differentiation.
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Affiliation(s)
- Sarah M Burke
- Brain & Development Research Centre, Department of Developmental and Educational Psychology, Leiden University, Leiden, The Netherlands.
- Department of Women's and Children's Health, Karolinska Institute and University Hospital, Stockholm, Sweden.
| | - Amir H Manzouri
- Stressmotagningen, S:t Göransgatan 84, 112 38, Stockholm, Sweden
| | - Ivanka Savic
- Department of Women's and Children's Health, Karolinska Institute and University Hospital, Stockholm, Sweden
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23
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Skorska MN, Blanchard R, VanderLaan DP, Zucker KJ, Bogaert AF. Gay Male Only-Children: Evidence for Low Birth Weight and High Maternal Miscarriage Rates. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:205-215. [PMID: 27549305 DOI: 10.1007/s10508-016-0829-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/24/2016] [Accepted: 08/02/2016] [Indexed: 06/06/2023]
Abstract
Recent findings suggest that there may be a maternal immune response underpinning the etiology of sexual orientation of gay male only-children. This maternal immune response appears to be distinct from that which is purported to explain the classic fraternal birth order effect found in studies of male sexual orientation. We tested two predictions related to the hypothesized maternal immune response in mothers of gay male only-children: (1) elevated fetal loss among mothers who have had gay male only-children and (2) lower birth weight in gay male only-children. Mothers of at least one gay son (n = 54) and mothers of heterosexual son(s) (n = 72) self-reported their pregnancy histories, including the birth weights of newborns and number of fetal losses (e.g., miscarriages). Mothers of gay male only-children (n = 8) reported significantly greater fetal loss compared with mothers of males with four other sibship compositions (gay with no older brothers, gay with older brothers, heterosexual only-children, heterosexual with siblings) (n = 118). Also, firstborn gay male only-children (n = 4) had a significantly lower birth weight than firstborn children in the four other sibship compositions (n = 59). Duration of pregnancy was not significantly different among the groups of firstborn children in the birth weight analyses. Thus, this study found further support for a distinct pattern of maternal immune response implicated in the etiology of male sexual orientation. Mechanisms that may underlie this potential second type of maternal immune response are discussed.
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Affiliation(s)
- Malvina N Skorska
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
| | - Ray Blanchard
- Department of Psychiatry, University of Toronto, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Doug P VanderLaan
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road N., Mississauga, ON, L5L 1C6, Canada
- Child, Youth and Family Division, Underserved Populations Research Program, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Kenneth J Zucker
- Department of Psychiatry, University of Toronto, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Anthony F Bogaert
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
- Department of Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
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Guillamon A, Junque C, Gómez-Gil E. A Review of the Status of Brain Structure Research in Transsexualism. ARCHIVES OF SEXUAL BEHAVIOR 2016; 45:1615-48. [PMID: 27255307 PMCID: PMC4987404 DOI: 10.1007/s10508-016-0768-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/22/2015] [Accepted: 04/29/2016] [Indexed: 05/22/2023]
Abstract
The present review focuses on the brain structure of male-to-female (MtF) and female-to-male (FtM) homosexual transsexuals before and after cross-sex hormone treatment as shown by in vivo neuroimaging techniques. Cortical thickness and diffusion tensor imaging studies suggest that the brain of MtFs presents complex mixtures of masculine, feminine, and demasculinized regions, while FtMs show feminine, masculine, and defeminized regions. Consequently, the specific brain phenotypes proposed for MtFs and FtMs differ from those of both heterosexual males and females. These phenotypes have theoretical implications for brain intersexuality, asymmetry, and body perception in transsexuals as well as for Blanchard's hypothesis on sexual orientation in homosexual MtFs. Falling within the aegis of the neurohormonal theory of sex differences, we hypothesize that cortical differences between homosexual MtFs and FtMs and male and female controls are due to differently timed cortical thinning in different regions for each group. Cross-sex hormone studies have reported marked effects of the treatment on MtF and FtM brains. Their results are used to discuss the early postmortem histological studies of the MtF brain.
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Affiliation(s)
- Antonio Guillamon
- Departamento de Psicobiología, Universidad Nacional de Educación a Distancia, c/Juand del Rosal, 10, 28040, Madrid, Spain.
- Academia de Psicología de España, Madrid, Spain.
| | - Carme Junque
- Departamento de Psiquiatría y Psicobiología Clínica, Universidad de Barcelona, Barcelona, Spain
- Institute of Biomedical Research August Pi i Sunyer, Barcelona, Spain
| | - Esther Gómez-Gil
- Institute of Biomedical Research August Pi i Sunyer, Barcelona, Spain
- Unidad de Identidad de Género, Hospital Clinic, Barcelona, Spain
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Abé C, Ekman CJ, Sellgren C, Petrovic P, Ingvar M, Landén M. Cortical thickness, volume and surface area in patients with bipolar disorder types I and II. J Psychiatry Neurosci 2016; 41:240-50. [PMID: 26645741 PMCID: PMC4915933 DOI: 10.1503/jpn.150093] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Bipolar disorder (BD) is a common chronic psychiatric disorder mainly characterized by episodes of mania, hypomania and depression. The disorder is associated with cognitive impairments and structural brain abnormalities, such as lower cortical volumes in primarily frontal brain regions than healthy controls. Although bipolar disorder types I (BDI) and II (BDII) exhibit different symptoms and severity, previous studies have focused on BDI. Furthermore, the most frequently investigated measure in this population is cortical volume. The aim of our study was to investigate abnormalities in patients with BDI and BDII by simultaneously analyzing cortical volume, thickness and surface area, which yields more information about disease- and symptom-related neurobiology. METHODS We used MRI to measure cortical volume, thickness and area in patients with BDI and BDII as well as in healthy controls. The large study cohort enabled us to adjust for important confounding factors. RESULTS We included 81 patients with BDI, 59 with BDII and 85 controls in our analyses. Cortical volume, thickness and surface area abnormalities were present in frontal, temporal and medial occipital regions in patients with BD. Lithium and antiepileptic drug use had an effect on the observed differences in medial occipital regions. Patients with the subtypes BDI and BDII displayed common cortical abnormalities, such as lower volume, thickness and surface area than healthy controls in frontal brain regions but differed in temporal and medial prefrontal regions, where only those with BDI had abnormally low cortical volume and thickness. LIMITATIONS The group differences can be explained by progressive changes, but also by premorbid conditions. They could also have been influenced by unknown factors, such as social, environmental or genetic factors. CONCLUSION Our findings suggest diagnosis-related neurobiological differences between the BD subtypes, which could explain distinct symptoms and point to potential biomarkers that could inform the subtype diagnosis of BD.
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Affiliation(s)
- Christoph Abé
- Correspondence to: C. Abé, Department of Clinical Neuroscience, Osher Center, Karolinska Institutet, Nobelsväg 9, 17177 Stockholm, Sweden;
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Gerwinn H, Pohl A, Granert O, van Eimeren T, Wolff S, Jansen O, Deuschl G, Huchzermeier C, Stirn A, Siebner HR, Ponseti J. The (in)consistency of changes in brain macrostructure in male paedophiles: A combined T1-weighted and diffusion tensor imaging study. J Psychiatr Res 2015; 68:246-53. [PMID: 26228426 DOI: 10.1016/j.jpsychires.2015.07.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 07/01/2015] [Accepted: 07/01/2015] [Indexed: 10/23/2022]
Abstract
Thus far, four studies have used magnetic resonance imaging (MRI) to test for differences in brain structure between paedophilic (i.e. sexually attracted to pre-pubescent children) and teleiophilic (i.e. sexually attracted to adults) men, revealing divergent results. To re-examine this issue, we acquired high resolution structural T1-weighted and diffusion MRI scans of the brain in 24 paedophilic and 32 teleiophilic men. We performed voxel-based morphometry (VBM) of the T1-weighted images and tract-based spatial statistics (TBSS) of the diffusion tensor imaging data to search for grey and white matter differences between groups. In contrast to previous studies, less than half of the individuals in our paedophilic group had a record of sexual offences against children, as subjects were partially recruited from two outpatient facilities of a child sexual abuse prevention project for self-acknowledged paedophiles. After adjustment for multiple comparisons and controlling for important confounding factors, we did not find any significant grey or white matter differences between the paedophilic and teleiophilic subjects. Together with the inconsistencies in the literature, these results argue against consistent structural differences at the macroanatomical scale between paedophiles and teleiophiles.
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Affiliation(s)
- Hannah Gerwinn
- Department of Neurology, Kiel University, Medical School, Arnold-Heller-Str. 3, 24105, Kiel, Germany.
| | - Alexander Pohl
- Department of Neurology, Kiel University, Medical School, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Oliver Granert
- Department of Neurology, Kiel University, Medical School, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Thilo van Eimeren
- Department of Neurology, Kiel University, Medical School, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Stephan Wolff
- Department of Radiology and Neuroradiology, Kiel University, Medical School, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Olav Jansen
- Department of Radiology and Neuroradiology, Kiel University, Medical School, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Günther Deuschl
- Department of Neurology, Kiel University, Medical School, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Christian Huchzermeier
- Institute of Sexual Medicine and Forensic Psychiatry and Psychotherapy, Centre for Integrative Psychiatry Kiel, Niemannsweg 147, 24105, Kiel, Germany
| | - Aglaja Stirn
- Institute of Sexual Medicine and Forensic Psychiatry and Psychotherapy, Centre for Integrative Psychiatry Kiel, Niemannsweg 147, 24105, Kiel, Germany
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Kettegaard Allé 30, 2650, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Bispebjerg Bakke 23, 2400, Copenhagen, Denmark
| | - Jorge Ponseti
- Institute of Sexual Medicine and Forensic Psychiatry and Psychotherapy, Centre for Integrative Psychiatry Kiel, Niemannsweg 147, 24105, Kiel, Germany
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