Your brain accounts for only about two percent of your body weight, but it’s responsible for 20 percent of the energy you use. That energy goes to support about one billion nerve cells and billions more support cells that make up the brain, and the hundreds of trillions of synapses connecting them all.
Now a new technique is giving scientists an unprecedented look at how the brain is put together. Called “diffusion tractography,” the technique uses computer analysis to look at the connections between brain cells, which cannot be observed with other forms of imaging. This allows researchers to learn not only about the individual brain regions but abut how those regions work together.
Recently, diffusion tractography was used to explore the role of the brain in vision and sight. Scientists at Carnegie Mellon University in Pittsburgh looked at the flow of information between the visual and parietal cortices. The visual cortex processes visual information, and the parietal cortex integrates that information provided by the visual and other cortices and helps direct voluntary movements.
The two brain areas work together to determine what you pay attention to. Communication over the synaptic pathways helps these parts of the brain direct focus to important things. Diffusion tractography made it possible for scientists to watch this communication happening.