Mapping human behavior to brain circuits has long been a goal for behavioral neurologists and neuropsychologists. Many discoveries were based on detailed psychological and anatomical studies of a single case. A famous example is Henry Gustav Molaison, better known as H.M.
In 1953, H.M. underwent bilateral hippocampectomy for the treatment of intractable epilepsy. After the surgery, he developed severe anterograde amnesia. His case was first described in 1957 and transformed our understanding of the hippocampus and its important role in human memory.1