The relationship of male testosterone to components of mental rotation.

Studies suggest that higher levels of testosterone (T) in males contribute to their advantage over females in tests of spatial ability. However, the mechanisms that underlie the effects of T on spatial ability are not understood. We investigated the relationship of salivary T in men to performance on a computerized version of the mental rotation task (MRT) developed by [Science 171 (3972) (1971) 701]. We studied whether T is associated specifically with the ability to mentally rotate objects or with other aspects of the task. We collected hormonal and cognitive data from 27 college-age men on 2 days of testing. Subjects evaluated whether two block objects presented at different orientations were the same or different. We recorded each subject's mean response time (RT) and error rate (ER) and computed the slopes and intercepts of the functions relating performance to angular disparity. T level was negatively correlated with ER and RT; these effects arose from correlations with the intercepts but not the slopes of the rotation functions. These results suggest that T may facilitate male performance on MRTs by affecting cognitive processes unrelated to changing the orientation of imagined objects; including encoding stimuli, initiating the transformation processes, making a comparison and decision, or producing a response.