Morphologic asymmetry of the human anterior cingulate cortex.

The anterior cingulate cortex (ACC) is thought to play a major role in executive processes. Studies assessing neuroanatomical attributes of this region report a high degree of morphological variability. Recent theories consider the fissurization of the cortex to be a product of gross mechanical processes related to cortical growth and local cytoarchitectural characteristics. Hence, local sulcal patterning and gray matter volume are supposed to be associated. ACC fissurization was quantified in left- and right-handers of both sexes by recording the presence and extension of the paracingulate sulcus (PCS). Differences between groups regarding local gray matter volume were assessed by means of optimized voxel-based morphometry (oVBM) including additional modulation. Overall, the PCS occurred more often and was more pronounced in the left as compared to the right anterior cingulate region, although hemispheric differences were less pronounced in male left- and female right-handers. These discrepancies between groups seem to stem from variations of cingulate morphology in the left rather than the right hemisphere. The pattern of relevant comparisons in the oVBM analysis indicated a similar interaction. Therefore, evidence was found for discrepancies between groups and hemispheres on the macrostructural level.