Brodmann (1909), a student of Cécile Vogt-Mugnier and Oskar Vogt, who worked on cercopithecus (and not much in human Bailey and von Bonin), elaborated a system of numeration that had unfortunately no typological logics (1, 2 and 3 are sensory, 4 is motor, 5 is parietal, 6 is premotor and 7 is again parietal!).
After the first attempts to divide the human cortex into areas according to the cytoarchitecture by Theodor Meynert, Vladimir Betz, Alfred Walter Campbell, Grafton Elliot Smith and Korbinian Brodmann, von Economo started his own project in 1912 and was joined by Georg N. Koskinas in 1919.