How many of the stories we tell about Gage are wrong? Well, a metal rod did fly through the guy’s skull but:
The day after his accident, a local newspaper misstated the diameter of the rod. A small error, but an omen of much worse to come…Within a few days, however, his health deteriorated. His face puffed up, his brain swelled, and he started raving, at one point demanding that someone find his pants so he could go outside. His brain developed a fungal infection and he lapsed into a coma…
[T]here’s no record of what Gage did in the months after the accident—and we know even less about what his conduct was like. Harlow’s case report fails to include any sort of timeline explaining when Gage’s psychological symptoms emerged and whether any of them got better or worse over time. Even the specific details of Gage’s behavior seem, on a closer reading, ambiguous, even cryptic. For instance, Harlow mentions Gage’s sudden “animal propensities” and, later, “animal passions.” Sounds impressive, but what does that mean? An excessive appetite, strong sexual urges, howling at the moon?
People butcher history all the time, of course, for various reasons. But something distinct seems to have happened with Gage. Macmillan calls it “scientific license.” “When you look at the stories told about Phineas,” he says, “you get the impression that [scientists] are indulging in something like poetic license—to make the story more vivid, to make it fit in with their preconceptions.”
Apparently there’s a minor industry in academia devoted to modeling rods being blown through people’s skulls. And this author is not impressed with Antonio Damasio.
In the end, I think Gage is a proxy for the idea that changes in the brain can cause changes in behavior: it’s hard to emotionally grasp that we’re controlled by a squishy thing in our skull until you have ‘seen it’.