Travis sez, "'H.M.' are the initials of a patient who had a portion of his brain removed many years ago to combat epilepsy. One of the unanticipated side effects was that he was unable to form new memories. Its a very famous case in the brain and cognitive sciences. Anyway, the guy died a little while ago and now they're turning his brain into 30,000 cross sectional slides. They're slicing it up right now and there's a live feed from the UCSD lab which is doing it."
The Brain Observatory – In Memory of H.M.
(Thanks, Travis!)