The legend of Phineas Gage, the railroad worker who had a 3.5″, 13 pound tamping iron blown through his skull, is touted to first-year psychology and neuroscience students the world over. Incredibly, Gage managed not to die from the injury, but he was a changed man. The doctors who studied him cited extreme behavioral changes, including “the grossest profanity.” (If you ask me, having a rod blown through your skull’ll do that to you. Amiright?)
How Phineas Gage even managed to survive having an iron spike shoved through his frontal lobe is a mystery, but whether or not the injury had anything to do with Post-Spike-Phineas’s dirty mouth has remained a mystery as well. In recent years, researchers have been trying to reconstruct Gage’s skull to see how the damage could have affected his behavior; now, neuroscientists at UCLA have produced Gage’s connectome–a detailed wiring diagram of his brain, showing how its long-range connections were altered by the injury.
The project is part of the larger Human Connectome Project which aims to build a comprehensive map of all the connections in the human brain. The import of the project is seemingly obvious–think what a fully-detailed map of the brain could tell us about mental disorders or how to repair neural damage.
In the image above, the lower left image shows the connectogram of 110 healthy right-handed males, the major highways and byways between brain regions. The lower right image shows the connections that were likely disrupted by the iron spike through Gage’s frontal lobe. The damage to connections between the frontal lobe and the limbic system certainly account for the changes in behavior Gage reportedly exhibited, as these connections play a major role in regulating emotion. But the reports only go so far, and even with Gage’s connectome, we still may never know the true extent of the damage.
That being said, how accurate and useful will connectomics actually prove to be? Be sure to check out this video of Carl Zimmer and Robert Krulwich moderating a debate on how much stock we should put in connectomics, and leave your comments below.