There has been another development in the ongoing effort to map the human brain. Using a new technique called diffusion tensor imaging, scientists at Indiana University have created the first high resolution map of the human cortical network:
Diffusion imaging is a new twist on MRI that uses magnetic resonance signals to track the movement of water molecules in the brain. In gray matter, water tends to diffuse multidirectionally. But in white matter, it diffuses along the length of neural wires, called axons, and scientists can use these diffusion measurements to map the fibers.
The node lies on the shortest path between many different parts of the neural network. “It’s highly connected amongst itself, but also highly central with respect to the rest of the brain,” says Sporns. “Network studies in other fields, from the Internet to protein interaction networks, suggest that these kinds of highly connected nodes tend to be very important for determining what the network does as a whole.”