"In 1953, 27-year-old Henry Gustave Molaison underwent an experimental brain surgery in an attempt to alleviate his severe epileptic seizures. The surgery left him with a form of amnesia; he could remember many things from the past, but was unable to form new memories."

"'He could tell us about where he was born, [that] his father's family was from Thibodaux, La., his mother came from Ireland,' says neuroscientist Suzanne Corkin. "He talked about the towns in Hartford where he lived and about his specific neighbors. He knew the schools he attended, some of his classmates' names."

"Corkin worked with and studied Molaison for almost 50 years, from 1962 until his death in 2008. She writes about how his case has helped scientists understand how memories are processed and stored in her new book Permanent Present Tense."