Jorge Ponseti1, Oliver Granert2, Olav Jansen3, Stephan Wolff4, Hubertus Mehdorn4, Hartmut Bosinski5, Hartwig Siebner6. 1. Section of Sexual Medicine, Kiel, Germany;. Electronic address: Ponseti@sexmed.uni-kiel.de. 2. Department of Neurology, Kiel, Germany. 3. Section of Neuroradiology, Kiel, Germany. 4. Department of Neurosurgery, Christian-Albrechts-University, Kiel, Germany. 5. Section of Sexual Medicine, Kiel, Germany. 6. Danish Research Center for Magnetic Resonance Imaging, Hvidovre University Hospital, Hvidovre, Denmark.
Abstract
INTRODUCTION: The assessment of sexual orientation is of importance to the diagnosis and treatment of sex offenders and paraphilic disorders. Phallometry is considered gold standard in objectifying sexual orientation, yet this measurement has been criticized because of its intrusiveness and limited reliability. AIM: To evaluate whether the spatial response pattern to sexual stimuli as revealed by a change in blood oxygen level-dependent (BOLD) signal can be used for individual classification of sexual orientation. METHODS: We used a preexisting functional MRI (fMRI) data set that had been acquired in a nonclinical sample of 12 heterosexual men and 14 homosexual men. During fMRI, participants were briefly exposed to pictures of same-sex and opposite-sex genitals. Data analysis involved four steps: (i) differences in the BOLD response to female and male sexual stimuli were calculated for each subject; (ii) these contrast images were entered into a group analysis to calculate whole-brain difference maps between homosexual and heterosexual participants; (iii) a single expression value was computed for each subject expressing its correspondence to the group result; and (iv) based on these expression values, Fisher's linear discriminant analysis and the kappa-nearest neighbor classification method were used to predict the sexual orientation of each subject. MEAN OUTCOME MEASURE: Sensitivity and specificity of the two classification methods in predicting individual sexual orientation. RESULTS: Both classification methods performed well in predicting individual sexual orientation with a mean accuracy of >85% (Fisher's linear discriminant analysis: 92% sensitivity, 85% specificity; kappa-nearest neighbor classification: 88% sensitivity, 92% specificity). CONCLUSION: Despite the small sample size, the functional response patterns of the brain to sexual stimuli contained sufficient information to predict individual sexual orientation with high accuracy. These results suggest that fMRI-based classification methods hold promise for the diagnosis of paraphilic disorders (e.g., pedophilia).
INTRODUCTION: The assessment of sexual orientation is of importance to the diagnosis and treatment of sex offenders and paraphilic disorders. Phallometry is considered gold standard in objectifying sexual orientation, yet this measurement has been criticized because of its intrusiveness and limited reliability. AIM: To evaluate whether the spatial response pattern to sexual stimuli as revealed by a change in blood oxygen level-dependent (BOLD) signal can be used for individual classification of sexual orientation. METHODS: We used a preexisting functional MRI (fMRI) data set that had been acquired in a nonclinical sample of 12 heterosexual men and 14 homosexual men. During fMRI, participants were briefly exposed to pictures of same-sex and opposite-sex genitals. Data analysis involved four steps: (i) differences in the BOLD response to female and male sexual stimuli were calculated for each subject; (ii) these contrast images were entered into a group analysis to calculate whole-brain difference maps between homosexual and heterosexual participants; (iii) a single expression value was computed for each subject expressing its correspondence to the group result; and (iv) based on these expression values, Fisher's linear discriminant analysis and the kappa-nearest neighbor classification method were used to predict the sexual orientation of each subject. MEAN OUTCOME MEASURE: Sensitivity and specificity of the two classification methods in predicting individual sexual orientation. RESULTS: Both classification methods performed well in predicting individual sexual orientation with a mean accuracy of >85% (Fisher's linear discriminant analysis: 92% sensitivity, 85% specificity; kappa-nearest neighbor classification: 88% sensitivity, 92% specificity). CONCLUSION: Despite the small sample size, the functional response patterns of the brain to sexual stimuli contained sufficient information to predict individual sexual orientation with high accuracy. These results suggest that fMRI-based classification methods hold promise for the diagnosis of paraphilic disorders (e.g., pedophilia).
Authors: Gilian Tenbergen; Matthias Wittfoth; Helge Frieling; Jorge Ponseti; Martin Walter; Henrik Walter; Klaus M Beier; Boris Schiffer; Tillmann H C Kruger Journal: Front Hum Neurosci Date: 2015-06-24 Impact factor: 3.169
Authors: Adam Safron; David Sylva; Victoria Klimaj; A M Rosenthal; Meng Li; Martin Walter; J Michael Bailey Journal: Sci Rep Date: 2017-02-01 Impact factor: 4.379
Authors: Małgorzata Wierzba; Monika Riegel; Anna Pucz; Zuzanna Leśniewska; Wojciech Ł Dragan; Mateusz Gola; Katarzyna Jednoróg; Artur Marchewka Journal: Front Psychol Date: 2015-09-10