Brain's voluntary chain-of-command ruled by not 1 but 2 captains

Scientists exploring the upper reaches of the brain's command hierarchy were astonished to find not one but two brain networks in charge, represented by the differently-colored spheres on the brain image above. Starting with a group of several brain regions implicated in top-down control (the spheres on the brain), they used a new brain-scanning technique to identify which of those regions work with each other. When they graphed their results (bottom half), using shapes to represent different brain regions and connecting brain regions that work with each other with lines, they found the regions grouped together into two networks. The regions in each network talked to each other often but never talked to brain regions in the other network. Credit: Washington University