Magnetic resonance imaging of the human frontal cortex reveals differential anterior-posterior variability of sulcal basins

MRI data of 100 healthy human brains were analyzed to establish a neuroanatomical map of the most frequently occurring 'sulcal basins' of the human frontal cortex. Sulcal basins are defined to be concavities in the white matter surface constituting/representing components of entire sulci. We determined their volume, depth, and interindividual variability. The sulcal basins were found to fall into two groups, on average, eight anterior basins in the prefrontal and premotor region and four posterior ones in the motor region of the frontal lobe. Compared to posterior basins, anterior basins are characterized by lower volume and depth. Furthermore, they showed greater interindividual variability in volume, depth, and occurrence. Our results indicate the existence of a mechanism for cortical folding which shows a greater flexibility in the phylogenetically younger, anterior prefrontal areas.