Morphological and functional variability in central and subcentral motor cortex of the human brain

There is a long-established link between anatomy and function in the somatomotor system in the mammalian cerebral cortex. Morphology of the central sulcus predicts the location of functional activation peaks in individuals, but morphological variation in the subcentral region and its relationship to functional activation is unknown. Investigating the subcentral region is particularly important in the context of speech, since control of the larynx during human speech production activates this region. Here, we examined whether morphological variation in the central and subcentral region is related to functional activation during movement of the hand, lips, tongue, and larynx at the individual subject level. We provide a systematic description of the sulcal pattern of the subcentral and adjacent opercular cortex, including the inter-individual variability of sulcal morphology. We found a robust relationship between morphology of the central and subcentral sulcal segments and movement of different effectors. A surface registration based on sulci revealed that anatomical variability explains, in part, spatial variability in function.