Kate Lunau’s latest dispatch from the AAAS Meeting on the most famous neurological patient in history. In 1953, at the age of 27, the man who later became known to scientists as “HM” lost his memory. Henry Gustav Molaison had suffered acute epileptic seizures, and as part of his treatment, he had part of his brain surgically removed, including much of the hippocampus. While the procedure helped alleviate his seizures, it left him unable to remember much of anything, including who he was. Before his death in 2008, HM partcipated in countless experiments, and helped give rise to an entirely new understanding of the human brain. At the AAAS Meeting, neuropsychologist Dr. Brenda Milner of the Montreal Neurological Institute and Hospital, who conducted pioneering studies of HM’s condition with her student Suzanne Corkin, discussed this famous case.