In 1953, a twenty-seven-year-old factory worker named Henry Molaison—who suffered from severe epilepsy—received a radical new version of the then-common lobotomy, targeting the most mysterious structures in the brain. The operation failed to eliminate Henry’s seizures, but it did have an unintended effect: Henry was left profoundly amnesic, unable to create long-term memories. Over the next sixty years, Patient H.M., as Henry was known, became the most studied individual in the history of neuroscience, a human guinea pig who would teach us much of what we know about memory today.
