One of the workhorses of cognitive neuroscience is thebrain map, which connects specific regions of the brain to our behaviors. Dr. Ming Hsu of the University of California, Berkeley says that the idea of brain mapping dates back to the Civil War.

"For the first time you have modern artillery and basically rifles that travel at speeds fast enough to produce very focal damage to the brain yet the person is still alive so that doctors can examine them.So before if you get a lesion to the brain, you’re probably dead. After the Civil War and onwards, you can actually live with damage to the brain."

Doctors saw that damage to specific parts of the brain led to specific deficits in cognition and behavior as opposed to global declines.

"So you get damage to parietal cortex, some part of your visual system may be affected. Damage to other parts of the brain results in very focal language deficits."