No abstract

The inferior parietal lobule (IPL) - a neocortical region and part of the heteromodal association cortex (HASC) - has been hypothesized to exhibit sexual dimorphism, as do other HASC regions, particularly with regard to asymmetry. Using a reliable method for measuring IPL gray matter volume based upon individual sulcal-gyral landmarks, we measured this region on magnetic resonance imaging scans from a sample of 15 individually matched pairs of normal male and female subjects. Male subjects showed significantly larger left, but not right, IPL volumes when compared to females. Males also showed a leftward (left > right) asymmetry for the IPL, with a less marked opposite asymmetry in females. Such sexual dimorphisms may possibly underlie the subtle cognitive differences observed between the sexes.

This study provides further evidence of brain morphology sex differences in schizophrenia that possibly contribute to the differential clinical disease expression in men and women.