Hemispheric differences in variability of fissural patterns in parasylvianand cingulate regions of human brains

We have determined different patterns of fissurization in Broca's area, the gyrus of Heschl, the planum temporale, the inferior parietal lobe, and the cingulate sulcus. Such patterns were asymmetrically distributed, indicatin g increased folding on the left side in most cases. More folding can someti mes be related to a larger cortical area, resulting in increased processing capacities in the respective brain region. Furthermore, the brain regions associated with the asymmetrical sulci are involved in lateralized function s. Of special interest are the asymmetries observed in regions correspondin g to the inferior parietal lobe (the accessory postcentral sulcus and the i ntraparietal sulcus), which, according to recent studies, is involved in li nguistic working memory. We did not detect a tendency of distinct fissuriza tion patterns in a given brain region to be associated with specific patter ns in other fissures, indicating that the different fissure types develop i ndependently in each brain region and can therefore be determined by local processes. These descriptions are of relevance to imaging studies that inte nd to establish correspondences between gross morphology and functional par ameters such as behavior and brain activation. (C) 1999 Wiley-Liss, Inc.