At age 27, H.M., whose real name was Henry Molaison, underwent an experimental surgical treatment for his debilitating epilepsy. His surgeon removed the medial temporal lobe, including a structure called the hippocampus.
Thereafter, H.M. was unable to form new memories. His case brought about the idea that the hippocampus may have a crucial role in retaining learned facts, replacing the notion that memories are scattered throughout the brain. H.M. became the focus of more than 50 years of memory research, working closely with the researchers who had to introduce themselves every time they met.
“Much of what we know about human memory, it has one way or another to do with H.M.,” said study researcher Jacopo Annese, director of The Brain Observatory in San Diego.
After H.M.’s death in 2008, Annese and his colleagues cut the patient’s frozen brain into 2,401 slices, each 0.7-millimeters thick. They took a picture of every slice, and created a high-resolution, 3D model of his brain.
Source: live science