STRUCTURAL DIFFERENCES IN THE CEREBRAL-CORTEX OF HEALTHY FEMALE AND MALE-SUBJECTS - A MAGNETIC-RESONANCE-IMAGING STUDY

There are both reproductive and nonreproductive behavioral differences between men and women. Brain regions involved in determining sexual. behavior have been reported to differ between the sexes. Nonreproducti ve, cognitive functional differences between sexes might be reflected in higher-order cortical structural dimorphisms, which have not previo usly been studied, We hypothesized that cortical regions involved in v erbal behavior (which is sexually dimorphic) would differ between sexe s. Using magnetic resonance imaging, we assessed gray matter volumes i n several cortical regions in 17 women and 43 men. Women had 23.2% (do rsolateral prefrontal cortex) and 12.8% (superior temporal gyrus) grea ter gray matter percentages (corrected for overall brain size and age) than men in a language-related cortical region, but not in a more vis uospatially related cortical region. These data seem to establish sexu ally dimorphic structural differences in the cerebral cortex, consiste nt with prior cerebral blood flow reports.