HM is dead

Some papers and magazines recently included an obituary of H.M., the memory-loss patient who died last month.

In 1953, H.M. had an operation which aimed to reduce the frequency of his epileptic seizures. This included removal of a structure known as the hippocampus on both sides of his brain.

The result was that from then and for the rest of his life, H.M. has severe anterograde amnesia - he was unable to encode any new episodic or semantic memories, causing him to 'live in the past'. He was able to encode new procedural memories, however, and his working memory was intact too.

His case, although tragic, was hugely important in helping psychologists to locate memory functions, which had previously thought to be distributed throughout the brain.