Phineas Gage, commonly referred to as The Man With A Hole In His Head, shouldn’t have survived the ordeal that led to his not-so-clever moniker. Gage was a railroad worker in Vermont who was tasked with clearing away rocks for railroad tracks to be laid. But on one fateful workday Gage would go on to unintentionally influence the fields of psychology, neurology, and neuroscience.

On September 13, 1848 Gage was using an iron rod to tamp explosives in a hole when he accidentally scraped it across some rocks creating a spark that ignited the explosives. As a result, the three-and-a-half-foot iron rod was rocketed through his skull by entering his face just below his left eye and exiting out the top of his head.

Dr. John Harlow, the local doctor who kept Gage alive for 12 years after his accident and Gage himself, are revered throughout the field of neuroscience not only for surviving such a horrific accident, but for the effect it had on him later on. Following the accident, people close to Gage described him as erratic, unreliable, inappropriate, and prone to swearing. So how did this blow to the head cause noticeable changes to his personality and behavior?

Evidence from Gage’s injury, which would be considered a frontal lobe injury today, and his subsequent rehabilitation, would go on to explain how trauma to certain areas of the brain can result in irreversible changes to personality and behavior. He eventually passed away on May 21, 1860 at the age of 36 due to a series of epileptic seizures that were most likely caused by his injury. Gage’s head and the iron rod that passed through it can still be found on display at the Harvard Medical School.