Structural asymmetries in the human brain: a voxel-based statistical analysis of 142 MRI scans

The use of computational approaches in the analysis of high-resolution magn etic resonance images (MRI) of the human brain provides a powerful tool for in vivo studies of brain anatomy. Here, we report results obtained with a voxel-wise statistical analysis of hemispheric asymmetries in regional 'amo unts' of gray matter, based on MRI scans obtained in 142 healthy young adul ts. Firstly, the voxel-wise analysis detected the well-known frontal (right > left) and occipital (left > right) petalias. Secondly, our analysis conf irmed the presence of left-greater-than-right asymmetries in several poster ior language areas, including the planum temporale and the angular gyrus; n o significant asymmetry was detected in the anterior language regions. We a lso found previously described asymmetries in the cingulate sulcus (right > left) and the caudate nucleus (right > left). Finally, in some brain regio ns we observed highly significant asymmetries that were not reported before , such as in the anterior insular cortex (right > left). The above asymmetr ies were observed in men and women. Our results thus provide confirmation o f the known structural asymmetries in the human brain as well as new findin gs that may stimulate further research of hemispheric specialization.