Henry Molaison (H.M.)

Henry Molaison, known as H.M., was an American man who underwent brain surgery in 1953 to treat severe epilepsy. The procedure involved removing parts of his hippocampus, which resulted in profound memory loss. H.M. could not form new long-term memories, though his short-term memory and intelligence remained intact. His case became pivotal in neuroscience research, providing insights into the role of the hippocampus in memory formation. H.M.'s condition helped scientists understand the distinction between different types of memory and highlighted the importance of specific brain structures in learning and retaining information. His story continues to influence psychology and neuroscience.