Architectonic maps of monkey PfC, taken from four different studies. A, the widely cited cytoarchitectonic map of Macaca PfC by Walker (1940). In B and C maps from more recent studies of Macaca PfC by Carmichael and Price (1994) and Preuss and Goldman-Rakic (1991), respectively. D, from von Bonin (1938). In this parcellation the Cebus PfC was subdivided into three areas, FGP, frontalis granularis posterior; FGA, frontalis granularis anterior; FO, frontal orbital area and limbic anterior area, LA, in medial surface.