H.M. None

H.M., or Henry Molaison, was a patient who famously contributed to understanding memory. After a surgery to treat severe epilepsy in the 1950s, parts of his brain involved in memory (the hippocampus) were removed. This resulted in profound anterograde amnesia, meaning he couldn’t form new long-term memories, though his intelligence and short-term memory remained intact. His case helped scientists learn that the hippocampus plays a crucial role in converting short-term memories into lasting ones. H.M.’s condition provided key insights into how human memory works and the brain’s structure-function relationship.