hypermnesia

Perhaps the most famous individual to exhibit hypermnesia was a Russian man known as "S," whose amazing photographic memory was studied for 30 years by a psychologist in the early part of the 20th century. "Hypermnesia" sometimes refers to cases like that of "S," but it can also refer to specific instances of heightened memory (such as those brought on by trauma or hypnosis) experienced by people whose memory abilities are unremarkable under ordinary circumstances. The word hypermnesia, which has been with us since at least 1882, was created in New Latin as the combination of "hyper-" (meaning "beyond" or "super") and "-mnesia" (patterned after "amnesia"). It ultimately derives from the Greek word mnasthai, meaning "to remember."