EEG analysis of male to female transsexuals: discriminant function and source analysis.

A small series of consecutive, unmedicated male to female transsexuals were studied before hormonal treatment and prior to reassignment surgery. Quantitative EEG and LORETA source localization in the Eyes Open and Eyes Closed conditions were carried out, and they were compared to sinistral/ambilateral male and female controls, as the transsexual group was overwhelmingly sinistral. Discriminant function analysis and source localization showed that the transsexual group was similar to female heterosexual controls, with increased sources in the right hemisphere in the fast frequencies.