the initials of a patient, Henry Molaison (1926–2008), who became amnesic after undergoing bilateral temporal lobectomy in 1953 for the relief of intractable seizures. The case of HM, who was a patient of U.S. neurologist William Beecher Scoville (1906–1984), demonstrated the critical role of the hippocampus and surrounding structures in the process of memory formation and storage.