Figure 1. Human and chimpanzee connectome properties.

(A, B) Parcellation and connectome. The surface plots show the 114-region atlas (Supplementary file 1) on inflated cortical surfaces. The matrices represent the group-averaged structural connectivity between brain regions. (C) Structural connections that are human-specific, chimpanzee-specific, and shared between humans and chimpanzees. (D) Association of the weights of the connections shared between humans and chimpanzees. The solid line represents a linear fit with Pearson’s correlation coefficient (r) and p value (p). (E) Violin plot of the distribution of regional clustering coefficients. Each violin shows the first to third quartile range (black line), median (white circle), raw data (dots), and kernel density estimate (outline). p is the p value of the difference in the mean of the distribution between the species (two-sample t-test). (F) Violin plot of the distribution of regional path lengths. Violin plot details are similar to those in E. The surface plots show the spatial organization of the difference in path length between the species (i.e., human – chimpanzee) visualized on inflated human cortical surfaces. The negative–zero–positive values are colored as blue–white–red.