from Clinical/Therapeutic Issues
The researchers began with the hypothesis that homosexual brains and heterosexual brains would react differently to seeing the faces of males and females. They used a functional MRI technique to spot locations in the brain where reactions might be noted when subjects were exposed to the faces of men and women.
Researchers say they found that regardless of the gender or sexual orientation of the person tested, all subjects rated the attractiveness of both male and female faces very similarly. All subjects also showed virtual identical patterns of neutral activity in regions of the visual cortex and limbic system when exposed to male and female faces.
They found, however, that the gender of a viewed individual, when the sexual preference of the viewer was taken into account, did make a difference in the reactions seen in the thalamus and the orbitofrontal cortext, a region of the brain's reward circuity. Heterosexual women and homosexual men showed a greater response to a male's face; heterosexual men and homosexual women responded differently to a female's face.
According to an abstract of the study, researchers say: "Our findings suggest that sexual preference modulates face-evoked activiation in the reward circuitry." The study was supported by a Swiss National Science Foundation grant.