However, as the weeks passed, his friends and colleagues realised that the accident had seriously affected his personality. He was described as "fitful, irreverent, indulging at times in the grossest profanity which was not previously his custom, manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires".
Although the accident destroyed Gage's personal life, it resulted in a major breakthrough in the understanding of the brain. Scientists began to think of the brain as a series of modules, each one with different responsibilities. For example, the frontal lobes contain modules that control speech and motor functions, and also the modules that help people to behave rationally and interact socially. The rod had entered Gage's frontal lobes, leaving intact the bits that deal with speech and motor functions, but destroying the bits that made him sociable and rational.
Last year neuroscientists from all over the world gathered to mark the 150th anniversary of Gage's accident and to discuss his and similar cases. For example, in the early 1990s there was the case of "Elliot", who suffered from a brain tumour that pressurised and damaged his frontal lobes. After the tumour had been removed, he remained in control of all his physical faculties and scored highly on IQ tests, but he lacked social intelligence. Following years of success as a salesman, he lost his job, his wife divorced him, and a new business venture ended in bankruptcy.
The conference also discussed the various lines of research that Gage had inspired. Ann Streissguth at the University of Washington has been studying foetal alcohol syndrome, a range of conditions caused by exposure to alcohol while in the womb. The syndrome includes poor judgement and a lack of emotion, which was also true of Gage. Streissguth is currently testing the hypothesis that alcohol affects the frontal lobes in a way that is not dissimilar to the destruction caused by an iron rod.
Gage's accident created the science of behavioural biology and helped treat subsequent victims, but his own life was ruined. He could not hold down a job, he had to become a circus freak in order to survive and died at the age of 38. His skull can still be seen at the Warren Medical Museum of Harvard University.