The operation was officially sanctioned in 1953, reduced in scope in 1964 and further curtailed in 1967. It was officially halted in 1973. The program also engaged in illegal activities, including the use of U.S. and Canadian citizens as its unwitting test subjects, which led to controversy regarding its legitimacy.(p74) MKUltra used numerous methods to manipulate its subjects’ mental states and brain functions. Techniques included the covert administration of high doses of psychoactive drugs (especially LSD) and other chemicals, electroshocks,hypnosis,sensory deprivation, isolation, and verbal and sexual abuse, in addition to other forms of torture.