title: Specific cerebral activation due to visual erotic stimuli in male-to-female transsexuals compared with male and female controls: an fMRI study.
abstract: BACKGROUND
  Transsexuals harbor the strong feeling of having been born to the wrong sex. There is a continuing controversial discussion of whether or not transsexualism has a biological representation. Differences between males and females in terms of functional imaging during erotic stimuli have been previously described, revealing gender-specific results.
  
  
  OBJECTIVE
  Therefore, we postulated that male-to-female (MTF) transsexuals may show specific cerebral activation differing from their biological gender.
  
  
  METHODS
  Cerebral activation patterns during viewing of erotic film excerpts in functional magnetic resonance imaging (fMRI).
  
  
  METHODS
  Twelve male and 12 female heterosexual volunteers and 12 MTF transsexuals before any treatment viewed erotic film excerpts during fMRI. Additionally, subjective rating of sexual arousal was assessed. Statistics were performed using the Statistical Parametric Mapping software.
  
  
  RESULTS
  Significantly enhanced activation for men compared with women was revealed in brain areas involved in erotic processing, i.e., the thalamus, the amygdala, and the orbitofrontal and insular cortex, whereas no specific activation for women was found. When comparing MTF transsexuals with male volunteers, activation patterns similar to female volunteers being compared with male volunteers were revealed. Sexual arousal was assessed using standard rating scales and did not differ significantly for the three groups.
  
  
  CONCLUSIONS
  We revealed a cerebral activation pattern in MTF transsexuals compared with male controls similar to female controls compared with male controls during viewing of erotic stimuli, indicating a tendency of female-like cerebral processing in transsexualism.
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany. elke.gizewski@uni-due.de
authors.forename: Elke R
authors.initials: ER
authors.lastname: Gizewski
authors.forename: Eva
authors.initials: E
authors.lastname: Krause
authors.forename: Marc
authors.initials: M
authors.lastname: Schlamann
authors.forename: Friederike
authors.initials: F
authors.lastname: Happich
authors.forename: Mark E
authors.initials: ME
authors.lastname: Ladd
authors.forename: Michael
authors.initials: M
authors.lastname: Forsting
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Senf