Fig. 6.

Average cortical thickness of all concave, saddle, and convex shaped points in 12 primate species with respect to total cortical surface area of each species. Cortical thickness is greatest for convex shapes, smallest for concave shapes, and in the middle for saddle shapes for all species. N = 31, N = 54, and N = 501 for rhesus macaques, chimpanzees, and humans respectively. Error bars represent one standard deviation. For species with single subjects, gray error bars represent variation within subjects. For species with multiple subjects, black error bars represent variation across subjects.