Trapped in the Past
Henry Molaison could not remember anything that happened to him after 1953, when he had brain surgery to treat epilepsy. While removing the areas causing his seizures, doctors unknowingly removed the parts of his brain that store long-term memories, including both hippocampi.
From then on, his doctor had to introduce herself everyday, over and over, for 30 years. Henry's short-term memory remained, so he could carry on an intelligent conversation. He just couldn't remember it afterwards! This unfortunate case study revealed the role of the hippocampus in forming long-term memories.