H.M., as he came to be known in the medical literature, could no longer remember anything he did. He could not remember what he had eaten for breakfast, lunch, or supper, nor could he find his way around the hospital. He failed to recognize hospital staff and physicians whom he had met only minutes earlier. Every time he met a scientist from MIT who was studying him regularly, she had to introduce herself again. He could not even recognize himself in recent photos, thinking that the face in the image was some “old guy.” Yet he was able to carry on a conversation for as long as his attention was not diverted.