FLUCTUATIONS OF PERCEPTUAL ASYMMETRY ACROSS TIME IN WOMEN AND MEN - EFFECTS RELATED TO THE MENSTRUAL-CYCLE

Women and men performed the same tachistoscopic chair identification task and free-vision face processing task during each of three test sessions. For women, the first and third sessions were performed during two successive periods of menstruation and the second session was performed during the intervening midluteal phase of the menstrual cycle. For men, the three test sessions were presented at 2-week intervals. For the chair identification task, there was no visual field (hemispheric) asymmetry for men during any of the three test sessions. For women, there was a right visual field (left-hemisphere) advantage during the second (midluteal) test session, but not during the first and third (menstrual) sessions. For the free-vision face processing task, there was a robust left-side (right-hemisphere) bias during all test sessions for both women and men and no effect of test session for either gender. Results for the nonlateralized chair identification task are consistent with the hypothesis that, in women, the left hemisphere is more activated during the midluteal phase of the menstrual cycle relative to the menstrual phase. Results for the lateralized face processing task suggest that hemispheric dominance for specific aspects of information processing are less likely to show such phase-related effects.