Horizon reveals the latest research into one of the most mysterious and common human experiences - pain.Breakthroughs have come from studying a remarkable woman in London who has felt no pain at all in her life a man in the US who cut off his own arm to survive and three generations of an Italian family who dont feel extremes of temperature.We witness a new treatment that involves a pioneering computer game snow world that contains the power to banish pain.And we find how powerfully our moods and emotions shape what pain we feel.   ... >>