Contrast sensitivity and emotion recognition across the menstrual cycle
Findings within the current literature demonstrate that certain aspects of female perception may be influenced by fluctuation in reproductive hormones associated with the menstrual cycle. Cyclic shifts in female mate preferences, facial recognition and low-level visual processing have been attributed to such hormonal variations. The cycle shift hypothesis posits that such systematic shifts in female perception provide an evolutionarily valuable function, selected by nature to harness females’ inclusive fitness. However, there are a number of limitations facing this evolutionary account, one of which is the lack of a mechanistic explanation of such changes in female perception. In a novel approach to investigating candidate mechanisms of this cyclic variation, experiment 1 measured contrast sensitivity across the menstrual cycles of naturally cycling women and women using combined-oral contraception, and also in males. Findings showed no difference in contrast sensitivity between male and female participants, where no differences were observed across the menstrual cycles in either female group. The second experiment was an extension of this, based on a growing body of evidence suggesting that higher-level perceptual processes such as facial emotion perception are driven wholly by low-level processing of basic visual properties. The second experiment investigates the role of low-level visual processing in emotion detection both between and within men and women. It also measures these low-level processes between ovulating and menstruating women as an investigation of the role that variation in female fertility may play in such basic processes. Findings from experiment 2 were consistent with current evidence of low-level visual processes accounting for aspects of facial emotion perception, however revealed no differences between or within sexes. Together these results are discussed within context to current evolutionary theories of facial processing in women.
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