Hormone therapy in postmenopausal women affect manual asymmetries
Bayer, U., and Hausmann, M.
Department of Psychology, University of Durham, United Kingdom
Previous research has shown that hormone therapy (HT) in postmenopausal women affect perceptual cerebral asymmetries. Yet, it is not clear whether sex hormonal changes in functional cerebral asymmetries also apply to fine motor coordination. The present study investigated HT-related effects on manual asymmetries in right-handed postmenopausal women who received HT either with estrogen (E) alone (n=15), an E-gestagen combination (n= 21) or without HT (control group, n=26). Saliva estradiol and progesterone levels were determined by chemiluminescence assays. Manual asymmetries were assessed in a finger tapping paradigm comprising three conditions of increasing complexity. Overall, the control group exhibited a right hand-superiority, particularly in the most complex condition. In contrast, both HT groups revealed an estradiol-related increase in manual asymmetries in the simple condition but a bilateral performance in the two complex conditions. The results suggest that the mechanisms underlying manual asymmetries are modulated by HT as a result of estrogen-related changes.