Sexual Dimorphism in the Human Corpus Callosum After Controlling for Brain Size

Babak A. Ardekani¹

A number of studies have reported that, "relative to brain size," the mid-sagittal corpus callosum cross-sectional area (CCA) in females is on average larger than in males. However, others suggest that these may be spurious differences created in the CCA-to-brain-size ratio because brain size tends to be larger in males. To help resolve this controversy, we measured the CCA on structural MRI scans of normal young adults (n=74, 37 males, 18-29 years), matched closely for brain size, from the OASIS (Open Access Series of Imaging Studies) cross-sectional dataset. Females had a significantly larger CCA (P<0.0005).