The brain and the rest of the nervous system are bidirectional and highly interconnected, meaning one must view the brain as a proxy for the entire nervous system to understand human function.

“The nervous system, the brain, the spinal cord, and all the connections to the body and back to the brain and spinal cord are bidirectional and highly interconnected. So, when we say brain, I'm more or less using it as a proxy for whole nervous system, including body.”