In 1953, a young man named Henry Molaison underwent an experimental operation that doctors hoped would control his frequent epileptic seizures. When the surgeon could not locate the origin of Molaison’s seizures, he removed a structure known as the hippocampus from both sides of his brain.
Soon after the surgery, Molaison’s doctors realized that the procedure had had a dramatic and unintended consequence: Molaison could no longer form new memories. This tragic loss for Molaison and his family turned him into one of the most important patients in the history of neuroscience. In fact, his case answered more questions about how memory works than the entire previous century of research, writes Suzanne Corkin, MIT professor of neuroscience emerita, in her new book, “Permanent Present Tense.”