Sex Hormones Affect Interhemispheric Connectivity during the Menstrual Cycle: An fMRI study

Introduction: Sex differences in a number of cognitive abilities are well documented. Although performances of both genders overlap to a large degree, women tend to outperform men in many aspects of verbal ability, while men tend to outperform women in spatial tasks (Halpern, 1996). It has repeatedly been shown that functional asymmetries are more pronounced in men, while they are less developed in women (e.g. Hausmann & Güntürkün, 1999). Furthermore, the lateralization of cognitive functions in women fluctuates during the menstrual cycle (e.g. McCourt et al., 1997; Sanders & Wenmoth, 1998). Thus, sex hormones s…