Who's that walking with a hole in his head?

Phineas P. Gage (1823–1860) was an American railroad construction foreman remembered for his improbable[C] survival of a rock-blasting accident in which a large iron rod was driven completely through his head, destroying much of his brain's left frontal lobe, and for that injury's reported effects on his personality and behavior over the remaining twelve years of his life—effects so profound that (for a time at least) friends saw him as "no longer Gage."

Long known as "the American Crowbar Case"—once termed "the case which more than all others is calculated to excite our wonder, impair the value of prognosis, and even to subvert our physiological doctrines"[2]—Phineas Gage influenced nineteenth-century discussion about the mind and brain, particularly debate on cerebral localization, and was perhaps the first case to suggest that damage to specific parts of the brain might affect personality.[1]:ch7-9[3]

Gage is a fixture in the curricula of neurology, psychology and related disciplines, and is frequently mentioned in books and academic papers; he even has a minor place in popular culture.[4] Despite this celebrity,[5] the body of established fact about Gage and his personality before or after his injury is small. This has allowed the psychology field to attribute "the fitting of almost any theory [desired] to the small number of facts we have"[1]:290. Through the intervening century, Gage has been cited in support of various contradictory theories of the brain. A survey of published accounts, including scientific ones, has found that they almost always severely distort Gage's behavioral changes, exaggerating the known facts when not directly contradicting them.

Two photographs of Gage, and a physician's report of his physical and mental condition late in life, were published in 2009 and 2010. This new evidence indicates that Gage's most serious mental changes may have been temporary. It suggests that in his later life, he was far more functional, and socially far better adjusted, than was previously assumed. A social recovery hypothesis suggests that Gage's employment as a stagecoach driver in Chile provided daily structure, allowing him to relearn lost social and personal skills.