Although he had a law degree he was remembered a a pioneer in using hypnosis to influence and actually control human behavior. He worked with CIAs Operation Artichoke which was the forerunner of MKUltra and the work of Jolly West.  He began with the premise: "Can we get control of an individual to the point where he will do our bidding against his will and even against fundamental laws of nature, such as self-preservation?"

Bryan was a mad scientist, referred to some a a “Luciferian psychopath”. He has been accused (or credited) with being a handler of Sirhan Sirhan. Others said his work was behind Arthur Bremer's attempt to kill Alabama Governor George Wallace.

He was more public about his work than many in his field... to the point where he served as the technical adviser for the 1962 film Manchurian Candidate. Perhaps he was a bit too public.

He died in a Los Angeles hotel room of “natural causes” after which an autopsy was conducted to confirm the official conclusion.