Henry Molaison

Henry Molaison, often referred to as HM, was an American man who became a pivotal figure in neuroscience after undergoing experimental surgery in 1953 to treat his severe epilepsy. The surgery involved the removal of parts of his hippocampus, which resulted in profound anterograde amnesia, preventing him from forming new long-term memories. His unique condition allowed researchers to study the role of the hippocampus in memory formation, leading to significant insights into the mechanisms of memory and learning. HM remained unable to create new memories until his death in 2008, making him one of the most studied patients in the history of neuroscience.