Rüdiger Gamm

Rüdiger Gamm is a German "mental calculator". He attained the ability to mentally evaluate large arithmetic expressions at the age of 21. He can also speak backwards, and calculate calendars. Featured on the Discovery Channel program The Real Superhumans, he was examined by Allan Snyder, an expert on savants, who concluded that Gamm's ability was not a result of savant syndrome but connected to genetics.