HM (Henry Molaison)

Henry Molaison, often referred to as HM, was a man who underwent brain surgery in 1953 to treat severe epilepsy. The procedure involved removing parts of his hippocampus, which led to significant memory loss. While he could still learn new skills, HM could not form new long-term memories or remember events for more than a few minutes. His case became pivotal in neuroscience, illustrating the vital role of the hippocampus in memory formation and providing valuable insights into how different types of memory work, shaping our understanding of the brain's memory systems.