Estrogen and memory in a transsexual population.

The association between administered estrogen and performance on verbal memory and other cognitive tasks was examined. Male-to-female transsexuals undergoing estrogen treatment for sex reassignment (n = 29) scored higher on Paired Associate Learning (PAL) compared to a similar transsexual control group, awaiting estrogen treatment (n = 30) (P < 0.05). No differences between groups receiving and not receiving estrogen were detected on a control memory task (Digit Span) or on other cognitive tasks including Mental Rotations and Controlled Associations. There were no group differences in age. Group differences in mood or in general intellectual ability also did not explain the findings. Results suggest a specific influence of estrogen in men on verbal memory tasks, similar to that seen in prior studies of women. They are discussed in terms of differential processing demands of the two memory tasks and possible differences between estrogenic influences on Mental Rotations and Controlled Associations in men versus women.