How important is the prefrontal cortex for self-control? One way to answer that question is to look at what happens when you lose it. The most famous case of prefrontal cortex brain damage is the story of Phineas Gage. And fair warning, this is a gory story. You might want to put down your sandwich.
In 1848, Phineas Gage was a twenty-five-year-old foreman for a gang of rail workers. His employers called him their best foreman, and his team respected and liked him. His friends and family called him quiet and respectful. His physician, John Martyn Harlow, described him as exceptionally strong in both mind and body, “possessing an iron will and an iron frame.”
But all that changed on Wednesday, September 13, at four-thirty p.m. Gage and his men were using explosives to clear a path through Vermont for the Rutland and Burlington Railroad. Gage’s job was to set up each explosion. This procedure had gone right a thousand times, and yet this time, something went wrong. The explosion happened too soon, and the blast sent a three-foot, seven-inch tamping iron straight into Gage’s skull. It pierced his left cheek, blew through his prefrontal cortex, and landed thirty yards behind him, carrying some of Gage’s grey matter with it.
You might now be picturing Gage, flat on his back, instantly killed. But he didn’t die. By witness reports, he didn’t even pass out. Instead, his workers put him in an oxcart and pushed him almost a mile back to the tavern where he was staying. His physician patched him up as well as possible, replacing the largest fragments of skull recovered from the accident site, and stretching the scalp to cover the wounds.
Gage’s full physical recovery took over two months (set back perhaps as much by Dr Harlow’s enthusiasm for prescribing enemas as by the persistent fungus growing out of Gage’s exposed brain). But by November 17, he was sufficiently healed to return to his regular life. Gage himself reported “feeling better in every respect,” with no lingering pain.
Sounds like a happy ending. But unfortunately for Gage, the story doesn’t end there. His outer wounds may have healed, but something strange was happening inside Gage’s brain. According to his friends and coworkers, his personality had changed. Dr Harlow described the changes in a follow-up to his original medical report of the accident:
The balance . . . between his intellectual faculties and his animal propensities seems to have been destroyed. He is 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 . . . devising many plans of future operation, which are no sooner arranged than they are abandoned.... In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was “no longer Gage.”
In other words, when Gage lost his prefrontal cortex, he lost his will power, his won’t power, and he wants power. His iron will—something that had seemed like an unshakable part of his character—had been destroyed by the tamping iron that blew through his skull.
Most of us don’t have to worry about ill-timed railroad explosions robbing us of our self-control, but we all have a little Phineas Gage in us. The prefrontal cortex is not always as reliable as we’d like. Many temporary states —like being drunk, sleep-deprived, or even just distracted—inhibit the prefrontal cortex, mimicking the brain damage that Gage sustained. This leaves us less able to control our impulses, even though our grey matter is still safe in our skulls. Even when our brains are well-rested and sober, we aren’t fully out of danger. That’s because while we all have the capacity to do the harder thing, we also have the desire to do exactly the opposite. This impulse needs to be restrained, and as we’ll see, it often has a mind of its own.
0 Comments