MORPHOMETRY OF THE SYLVIAN FISSURE AND THE CORPUS-CALLOSUM, WITH EMPHASIS ON SEX-DIFFERENCES

The relationship between anatomical asymmetries in the perisylvian region and the sizes of different regions of the corpus callosum was investigated post-mortem in 40 brains of right-handed hospital admissions (20 males, 20 females) with no cortical involvement. There were no sex differences either in anatomical asymmetries or in regional size of the callosum. There was a negative correlation between the absolute value of Sylvian fissure (planum temporale) asymmetries and the size of the isthmus in males but not in females. Further, there was a significant negative correlation between the size of the Sylvian fissure (or planum temporale) and the size of the callosal mid-body in males but not in females. There was no correlation between the asymmetry of the planum temporale \left-right\ and total size of the planum (left + right). These findings constrain theories about the ontogenesis of hemispheric specialization through changes in callosal connectivity and about sex differences in interhemispheric organization.