Functional MRI (fMRI) was used to examine gender effects on brain
activation during a language comprehension task. A large number of
subjects (50 women and 50 men) was studied to maximize the statistical
power to detect subtle differences between the sexes. To estimate the
specificity of findings related to sex differences, parallel analyses
were performed on two groups of randomly assigned subjects. Men and
women showed very similar, strongly left lateralized activation
patterns. Voxel-wise tests for group differences in overall activation
patterns demonstrated no significant differences between women and
men. In further analyses, group differences were examined by region of
interest and by hemisphere. No differences were found between the
sexes in lateralization of activity in any region of interest or in
intrahemispheric cortical activation patterns. These data argue
against substantive differences between men and women in the
large-scale neural organization of language processes.