Sex differences of event-related potential effects during three-dimensional mental rotation.

Sex differences in performance and in cortical activation patterns during mental rotation have rather consistently been reported. Data regarding sex differences of event-related potentials during the classic three-dimensional mental rotation task developed by Shepard and Metzler, however, are absent, and were therefore being addressed by this study. Mental rotation-related event-related potential effects were observed 900-1000 ms poststimulus at parietal electrodes and 600-700 as well as 800-900 ms poststimulus at right frontal leads, respectively. Sex differences, however, were observed already 400-700 ms poststimulus at right frontal electrodes. These findings suggest that sex differences during three-dimensional mental rotation occurred in relatively early cognitive processing stages presumably including perception and identification of stimuli instead of mental rotation itself.