The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science

by Norman Doidge

Explicit memory was discovered through observation of the most famous memory case in neuroscience—a young man named H.M., who had had severe epilepsy. To treat it, his doctors cut out a part of his brain the size of the human thumb, the hippocampus. (There are actually two “hippocampi,” one in each hemisphere, and both were removed.) After surgery H.M. at first seemed normal. He recognized his family and could conduct conversations. But it was soon apparent that since his operation, he could not learn any new facts. When his doctors visited him, chatted, left, and then returned again, he had no memory whatsoever of the previous meeting. We learn from H.M.’s case that the hippocampus turns our short-term explicit memories into long-term explicit memories for people, places, and things—the memories to which we have conscious access.

Hipppcampus means of creating long term memory