title: Neural Correlates of Sexual Orientation in Heterosexual, Bisexual, and Homosexual Men.
abstract: Studies of subjective and genital sexual arousal in monosexual (i.e. heterosexual and homosexual) men have repeatedly found that erotic stimuli depicting men's preferred sex produce strong responses, whereas erotic stimuli depicting the other sex produce much weaker responses. Inconsistent results have previously been obtained in bisexual men, who have sometimes demonstrated distinctly bisexual responses, but other times demonstrated patterns more similar to those observed in monosexual men. We used fMRI to investigate neural correlates of responses to erotic pictures and videos in heterosexual, bisexual, and homosexual men, ages 25-50. Sixty participants were included in video analyses, and 62 were included in picture analyses. We focused on the ventral striatum (VS), due to its association with incentive motivation. Patterns were consistent with sexual orientation, with heterosexual and homosexual men showing female-favoring and male-favoring responses, respectively. Bisexual men tended to show less differentiation between male and female stimuli. Consistent patterns were observed in the whole brain, including the VS, and also in additional regions such as occipitotemporal, anterior cingulate, and orbitofrontal cortices. This study extends previous findings of gender-specific neural responses in monosexual men, and provides initial evidence for distinct brain activity patterns in bisexual men.
authors.affiliation: Department of Psychology, Northwestern University, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Safron
authors.affiliation: Department of Psychology, Northwestern University, USA.|Department of Psychiatry, Kaiser Permanente, USA.
authors.forename: David
authors.initials: D
authors.lastname: Sylva
authors.affiliation: Department of Psychology, Northwestern University, USA.
authors.forename: Victoria
authors.initials: V
authors.lastname: Klimaj
authors.affiliation: Department of Psychology, Northwestern University, USA.|Department of Psychiatry, Kaiser Permanente, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Rosenthal
authors.affiliation: Department of Neurology, Otto von Guericke University Magdeburg, Germany.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Neurology, Otto von Guericke University Magdeburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Walter
authors.affiliation: Department of Psychology, Northwestern University, USA.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Bailey
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D020010:Heterosexuality / Q000502:physiology*; D018451:Homosexuality, Male; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D012725:Sexual Behavior / Q000502:physiology*; D000072339:Sexual and Gender Minorities