manifesting little deference for his fellows, impatient of restraint or advise
when it conflicts with his desires, at times pertinaciously obstinate, yet
capricious and vacillating, devising plans of future operations, which are
now sooner arranged than they are abandoned in turns for others appearing
more feasible,” wrote his physician in a Massachusetts medical
publication.^3 Here was a patient, who at least in the short term, suffered a
dramatic change in personality, without losing his ability to move his
limbs, speak, or process information. The obvious conclusion was that the
“frontal lobes,” the portion of the brain that lies over the eyes, had no role
in moving the limbs, controlling speech, or controlling facial functions.
More importantly, the case of Phineas Gage is one of the earliest “lesion
case studies” in which loss of a specific portion of the brain reveals the
function of that part. Although crudely understood for decades, the
concept of cerebral localization would flourish as scientists developed
more precise ways of delving into the mind.
Pierre Paul Broca (1824–1880) was a French physician who had trained
with some of the most esteemed medical practitioners throughout Paris in
the mid–19th century, and then alternately practiced pathology, surgery,
and anatomy. Broca was an inveterate investigator, broadly curious, and
deeply committed to medical research and publication. In 1861, Broca was
summoned to the Bicétre Hospital to examine a patient who had lost the
ability to speak. The Bicétre Hospital was a suburban Paris hospital that
specialized in mental illness, but Broca arrived not to evaluate a mentally
ill patient, but a fifty-one-year-old man who had not spoken for twenty-
one years—other than the word “tan.” So well-known was his singular
vocabulary word that he was not called by his name, Louis Victor
Leborgne, but by the moniker “Tan.”
During the first decade of his stay at Bicétre, Tan’s only limitation was
his inability to speak. Broca later reported that his “intelligence seemed
unaffected, his mental and physical faculties, intact and responsive ... he
never stopped trying to communicate.”^4 In the years before his encounter
with Broca, his right side had become paralyzed, and gangrene of the
limbs was hastening death. Even in a near-death state, Broca and the
patient Leborgne were able to interact. As always, his only utterance was
“tan,” but Broca determined that he was able to comprehend the language
of others, follow commands, and track numbers.