How to Unlearn a Disease

My father, a neurologist, once had a patient who was tormented, in the most visceral sense, by a poem. Philip was 12 years old and a student at a prestigious boarding school in Princeton, New Jersey. One of his assignments was to recite Edgar Allan Poe’s The Raven. By the day of the presentation, he had rehearsed the poem dozens of times and could recall it with ease. But this time, as he stood before his classmates, something strange happened.

Each time he delivered the poem’s famous haunting refrain—“Quoth the Raven ‘Nevermore’ ”—the right side of his mouth quivered. The tremor intensified until, about halfway through the recitation, he fell to the floor in convulsions, having lost all control of his body, including bladder and bowels, in front of an audience of merciless adolescents. His first seizure.

When my father heard this story, he decided to try an experiment. During Philip’s initial visit, he handed the boy a copy of and asked him to read it aloud. Again, at each utterance of the raven’s gloomy prophecy, Philip stuttered. His teeth clenched and his lips pulled sideward as though he were disagreeing with something that had been said. My father took the poem away before Philip had a full-blown fit. He wrote a note to the boy’s teacher excusing him from ever having to recite another piece of writing. His brain, my father explained, had