Psychic driving was a psychiatric procedure of the 1950s and 1960s in which patients were subjected to a continuously repeated audio message on a looped tape to alter their behaviour. In psychic driving, patients were often exposed to hundreds of thousands of repetitions of a single statement over the course of their treatment. They were also concurrently administered muscular paralytic drugs such as curare to subdue them for the purposes of exposure to the looped messages. The procedure was pioneered by Donald Ewen Cameron, and used and funded by the CIA's Project MKUltra program in Canada.