Mind & Body

How Phineas Gage's Freak Accident Changed Brain Science Forever

Today, we take it for granted that certain parts of the brain are responsible for certain aspects of our behavior. But in the 1800s, scientists were just grasping a rough understanding of the brain's purpose. That all changed — violently — on a fateful day in 1848, when an iron rod rocketed through the brain of a young rail foreman named Phineas Gage.

Fire in the Hole!

On September 13th, 1848, Gage was using explosives to clear rocks for the construction of a new rail line in Cavendish, Vermont. The work was simple, if a little dangerous: He'd drill a hole, fill it with explosive powder, pack it in with a tamping iron, then pour sand on top. But at one point, he tapped the iron in the hole, then turned to look at his men as he tapped it again. The tamping iron hit rock, creating a spark that detonated the explosive. That sent the 3.5-foot (1 meter) long, 1.25-inch (32 mm) wide, 13.25-pound (6 kg) bar skyward, directly into Gage's head. It entered through his left cheek, plowed through his eye socket, and blasted out the top of his skull, obliterating brain tissue in its wake. This was not his best day.

Surprisingly, not only did Gage survive the event, it's possible he never even lost consciousness. When he reached a doctor, he walked on his own two feet and was alert enough to show off some wit, uttering, "Here is business enough for you." (1800s-speak for "This oughta keep ya busy.")

It was Gage's personality, in fact, that landed him in the records of science history. The doctor, John Martyn Harlow, treated the now one-eyed Gage for a few months afterward and made notes of the peculiar ways he changed as a person. Those who knew him, Harlow noted, said that before the accident, he had a "well-balanced mind" and was a "shrewd, smart business man, very energetic and persistent in executing all his plans of operation." But afterward, he was a different person. He was "no longer Gage."

Diagram of where the tamping rod went through Gage's skull

"He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom)," Harlow wrote in a presentation to the Massachusetts Medical Society, "manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operation, which are no sooner arranged than they are abandoned in turn for others appearing more feasible."

A brain injury changed Gage's personality. Science had never seen this before.

Related Video: The Man with a Hole in His Brain

Neurology Ground Zero

"If you talk about hard core neurology and the relationship between structural damage to the brain and particular changes in behavior, this is ground zero," Harvard neurologist Allan Ropper told NPR. "It's one region [of the brain], it's really obvious, and the changes in personality were stunning." That makes it the ideal case to illustrate the role the brain plays in personality.

Since then, neuroscientists have visited and revisited that fateful day in 1848 to analyze Gage's injury with newer and newer technology. In the 1940s, a neurologist diagrammed the skull to determine the tamping iron's exact path through the brain. In the 1980s, scientists did the same thing with CT scans of Gage's skull; in the 1990s, they did it again with 3D computer models; and in 2012, they combined CT scans with MRI scans to map the brain networks that were affected in the accident.

Gage lived for 12 more years and even recovered from most of his personality changes before dying of a seizure that was probably related to his injury. But that tragic September day a century and a half ago is still echoing today: NFL players experience personality changes, depression, and dementia due to concussions suffered on the field. Celebrities known for their personalities, like Gary Busey and Tracy Morgan, dramatically changed after traffic accidents that led to traumatic brain injury. Brain injuries can happen to anyone, and we gained a deeper understanding of their effects thanks to Phineas Gage.

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To hear more about this turning point in brain science, check out "Phineas Gage: A Gruesome but True Story About Brain Science" by John Fleischman. The audiobook is free with a 30-day trial of Audible. We handpick reading recommendations we think you may like. If you choose to make a purchase through that link, Curiosity will get a share of the sale.

Written by Ashley Hamer December 5, 2017

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