The Strange Case Of Phineas Gage
Long before the advent of neuroscience, brain injuries have been used to deduce how the brain is organized into separate regions handling separate tasks. Consider the case of Phineas Gage, a 19th-century railroad construction foreman whose life was dramatically changed when a dynamite charge went off accidentally and blasted a 3 1/2-foot long, 1 1/4-inch in diameter, 13 1/2-pound iron tamping rod into his left cheek, through his upper jaw, through his brain behind his left eye, and out the top of his skull. That kind of injury would surely kill a person, right? Not necessarily. Gage was stunned, but not even knocked unconscious, and before long felt well enough to return to work. The problem was, as his friends and acquaintances said, he was no longer Gage.
The tamping rod had destroyed part of the frontal lobe of his brain (the left ventromedial part, according to reconstructions performed by University of Iowa neuroscientists Hanna and Antonio Damasio), with the bizarre result that his personality was, in effect, that of a completely different person. Instead of the responsible, conscientious man he had formerly been, he had somehow turned into a foul-mouthed, impulsive, irresponsible boor. Even though his intelligence and abilities were exactly the same as before the accident, he was unable to continue his work as foreman.
The strange case of Phineas Gage offers insight into the role that the brain's frontal lobes play in what are sometimes known as 'executive' functions: monitoring one's own behavior, controlling impulses, and generally acting like a mature, rational, socially responsible person. The disturbing thing about Gage's case is that it challenges some of our most basic assumptions about identity and morality, including some of the very assumptions on which our legal system is based. Gage was fully conscious of the consequences of his actions, but nevertheless acted antisocially. Are some sociopaths simply people with abnormalities of their frontal lobes, who are no more to blame for their actions than Gage was for his?
