Attend the tale of Phineas Gage. Honest, well liked by
friends and fellow workers on the Rutland and Burlington Railroad, Gage
was a young man of exemplary character and promise until one day in September
1848. While tamping down the blasting powder for adynamite charge, Gage
inadvertently sparked an explosion. The inch-thick tamping rod rocketed
through his cheek, obliterating his left eye on its way through his brain
and out the top of his skull. The rod landed several yards away, and Gage
fell back in a convulsive heap. Yet a moment later he stood up and spoke;
his fellow workers watched, aghast, then drove him by oxcart to a hotel,
where a local doctor, one John Harlow, dressed his wounds. As Harlow stuck
his index fingers into the holes in Gage's face and head until their tips
met, the young man inquired when he would be able to return to work.
Within two months, the physical organism that was Phineas Gage had completely recovered--he could walk, speak, and demonstrate normal awareness of his surroundings. But the character of the man did not survive the tamping rod's journey through his brain. In place of the diligent, dependable worker stood a foulmouthed and ill-mannered liar given to extravagant schemes that were never followed through. "Gage," said his friends, "was no longer Gage.
This past year neurobiologists Hanna and Antonio Damasio of the University of Iowa finally pinpointed what Gage had lost. The Damasios had long been interested in the case; in the intervening century it had become a classic in neurology textbooks. The scientific interest had begun with John Harlow, who on hearing of Gage's death in an epileptic fit 13 years after the accident persuaded the family to exhume the remains and donate the skull to medical research. Harlow believed that the change in Gage's personality had been wrought by damage to the frontal lobes of the brain. "The equilibrium . . . between his intellectual faculties and animal propensities seems to have been destroyed," Harlow wrote.
But nineteenth-century science had a hard time accepting the notion that a dollop of gray jelly could govern something so transcendent as social behavior. "Harlow was never given much credit," says Antonio Damasio. "Some people didn't even believe that Gage's story had ever happened.
So the Damasios decided, 130 years after the fact, to do an autopsy--to track down where, exactly, the damage in Gage's brain had occurred. Guided by anatomic clues on Gage's battered skull, now preserved in the Warren Medical Museum at Harvard, Hanna Damasio used computer modeling and neural imaging techniques to determine the path the tamping rod had taken through the brain. The most likely trajectory by far, the Damasios found, would have spared the regions of the frontal lobes necessary for language and motor function. But it would have done ruinous damage to a portion of the underbelly of the frontal lobes called the ventromedial region, especially on the left side.
Apparently the loss of that region is what made Gage so antisocial. This did not surprise the Damasios; in present-day patients whose ventromedial region has been damaged by tumor, accident, or surgery, they have observed the same sort of personality change as Gage's. But it was gratifying to solve a case that was at the root of so much modern research--and at the same time to pay homage to an underappreciated predecessor. "Gage's story was the historical beginnings of the study of the biological basis of behavior," says Antonio Damasio, "and the location of his lesion had always been a mystery. This was a way to give poor Dr. Harlow his due." --James Shreeve
