Figure 4.

Sequential topology of the primate visual system connectivity versus benchmark networks. (a) Minimization of the sequential layout of the primate visual cortical network and comparison networks with the same number of nodes and edges around a circular layout. Areas are placed around a circle in such a way that the total sum of the distances of all connected areas becomes minimal. By the value of this cost function, the organization of the actual network was found to be more sequential than that of randomized networks or other comparison networks, but less sequential than that of strictly sequential networks in which connections are arranged such that they only link immediate neighbours. (b) Optimal sequential layout of the primate visual cortical network along a linear one-dimensional axis. The arrangement largely resembles the expected sequence through the system, from primary visual areas (on the left) to higher-order areas (on the right). (Online version in colour.)