engleski

Functional hemispheric asymmetries in gender-biased vs. neutral verbal tasks

Introduction and aim: It has been suggested that activational effects of sex hormones, reflected in performance changes on gender-biased cognitive tasks, might be related to hormonally induced changes in laterality. The aim of this study was to examine this notion by exploring whether EEG patterns are gender- and menstrual phase specific only for gender-biased tasks. Method: 32 males and 39 females solved two types of verbal tasks: verbal fluency, previously shown to be gender- biased, and verbal reasoning, shown to be neutral. Women were tested twice, in early follicular and mid-luteal phases. EEG was recorded by a Nihon Kohden electroencephalograph with electrodes placed according to the international 10-20 system. The laterality scores (lnR–lnL) were calculated within the lower alpha frequency band on frontal electrodes. Results: Gender-biased task. Females performed better during mid-luteal than early follicular phase, but the gender difference reached only marginal significance. The laterality scores differed between genders, with males showing greater right hemisphere activation and females greater left hemisphere activation in both phases of the cycle. Gender-neutral task. The performance was not related to either gender or the phase of menstrual cycle. There were no significant changes in laterality scores as a function of menstrual cycle. Conclusion: For the gender-biased task the activational effects were observed in both performance and laterality scores, while for the gender-neutral task neither performance nor laterality scores changed throughout the menstrual cycle, A neat congruence between the two measures of activational effects suggests they might indeed be related to changes in laterality.

hemispheric asymmetries; sex differences; verbal tasks

nije evidentirano