Evolution of the Central Sulcus Morphology in Primates

The central sulcus (CS) divides the preand postcentral gyri along the dorsal-ventral plane of which all motor and sensory functions are topographically organized. The motorhand area of the precentral gyrus or KNOB has been described as the anatomical substrate of the hand in humans. Given the importance of the hand in primate evolution, here we examine the evolution of the motor-hand area by comparing the relative size and pattern of cortical folding of the CS surface area from magnetic resonance images in 131 primates, including Old World monkeys, apes and humans. We found that humans and great apes have a well-formed motor-hand area that can be seen in the variation in depth of Received: May 27, 2013 Returned for revision: June 22, 2013 Accepted after revision: March 20, 2014 Published online: August 13, 2014 William D. Hopkins, PhD Neuroscience Institute and Language Research Center Georgia State University PO Box 5030, Atlanta, GA 30302 (USA) E-Mail whopkin @ emory.edu © 2014 S. Karger AG, Basel 0006–8977/14/0841–0019$39.50/0