A Dutch psychologist, Joost A. M. Meerloo, caught the apocalyptic tone in a New York Times Magazine article in 1954: “The totalitarians have misused the knowledge of how the mind works for their own purposes. They have applied the Pavlovian technique  in a far more complex and subtle way, of course  to produce the reflex of mental and political submission of the humans in their power.”

Orwell’s hero in “1984,” Winston Smith, holds out hope against Big Brother and his minions: “With all their cleverness they had never mastered the secret of finding out what another human being was thinking.”

But the threat that they could riveted Americans  and the C.I.A.

Finding out what others are thinking was (and is) the job of spies. The Korean experience spurred the C.I.A.’s search for mind-control techniques to grill suspected double agents. The agency took on a task described in its documents as “overseas interrogations.”

Clandestine prisons were created in occupied Germany, occupied Japan and the Panama Canal Zone. “Like Guantánamo,” said a charter member of the C.I.A., Thomas Polgar. “It was anything goes.” In these cells, the agency conducted experiments in drug-induced brainwashing and other “special techniques” for interrogations. These continued inside and outside the United States, sometimes on unsuspecting human guinea pigs, long after the Korean War ended in 1953.

“There was deep concern over the issue of brainwashing,” Richard Helms, the former director of central intelligence, told the journalist David Frost 25 years later. “We felt that it was our responsibility not to lag behind the Russians or the Chinese in this field, and the only way to find out what the risks were was to test things such as L.S.D. and other drugs that could be used to control human behavior. These experiments went on for many years.”

Image FREED P.O.W.s released by North Korea told of torture and efforts to force confessions. Credit... Sfc. Al Chang/U.S. Army — National Archives — Time & Life Pictures — Getty Images

While the government chased after truth serum, fiction raced behind reality. The theory of a robot-like Manchurian Candidate was posited by the C.I.A. in 1953, six years before Richard Condon published the novel of that name, nine years before the book became a movie. William Burroughs, in “Naked Lunch” (1959), created a drug-addled mad scientist, Dr. Benway, “an expert on all phases of interrogation, brainwashing and control.”