Resistance is futile — or so Hollywood might have you believe about the burgeoning world of neuroscience.
In an updated version of the 1962 film, The Manchurian Candidate, evil-doers alter the memories of American veterans of the first Gulf War and then program them to kill on command years later.
For the original film, starring Frank Sinatra and Angela Lansbury, the programmed victims were Korean War veterans, and hypnosis and brainwashing were the main tools of corruption. In the remake, starring Denzel Washington and Meryl Streep, rogue scientists tap emerging brain science that has been tested or at least considered in recent years.
So how real is the possibility of mind control? It depends on how you define it, but scientists say current research comes close.
While a chip implant to change a person's memory hasn't surfaced, scientists have begun influencing memory using pharmaceuticals. And technology that has been tried extensively on animals can trigger the subjects to follow commands with the flick of a switch.
"These kind of innovations all have this feeling of being exciting, but also creepy," said Richard Glen Boire, founder of the Center for Cognitive Liberty and Ethics, a nonprofit awareness group in Davis, Calif.
Enhancing and Repressing Memory
One study, for example, found nine healthy middle-aged pilots who took the Alzheimer's drug Aricept remembered flight-simulator lessons much better than nine others who took a placebo. Aricept has unwanted side effects, but researchers are working on other drugs that have been shown to promote long-term memory in animals.
Certain drugs known as beta blockers, meanwhile, have been shown to suppress emotional memory. Some feel this holds promise for people with post traumatic stress disorder who have trouble leaving behind wrenching events of their past.
Taken for therapeutic purposes, none of these drugs may seem particularly harmful, but their emergence demonstrates scientists' ability to tinker with memory. If scientists can both suppress and enhance memory, the movie's consultants argues it's not a far leap to imagine the ability to replace a horrific war memory with a false one that glorifies a fellow soldier, as happens to Denzel Washington's character.
"We use the idea in the movie that we have come to the point where we have the ability to influence the brain, not just for therapeutic purposes, but for political ones," said Jay Lombard, director of the Brain Behavior Center in Nyack, N.Y., and a consultant on the film.
The potency of so-called psychopharmaceuticals may be relegated to Hollywood screenplays for now, but the potential for corruption is real enough to have caught the attention of the President's Council on Bioethics.
"Neuroscience and related technologies not only lead to knowledge, they lead to power," warned Robert Michels of Cornell University Medical College while speaking to the council last January about possible implications of memory enhancement and suppression.
Records show the government has long been interested in using drugs to influence the brain. In fact, lawsuits are now pending in federal courts from people who claim they were guinea pigs in the CIA's infamous MKULTRA project. In this top secret research, agents gave LSD and other drugs to hundreds of unsuspecting Americans during the Cold War.
Stopping Raging Bull
Brain stimulation technology has also long loomed as a means to control the actions of another living being. Starting in the late 1940s, scientists have zeroed in on key regions of the brain that, when stimulated, can produce lethargy or anger or irresistible sensations of pleasure.
Some of the most well-known studies on brain stimulation was by the Spanish scientist named Jose Delgado. Throughout his work in the 1950s and '60s, Delgado developed a procedure for implanting electrodes into areas of the brains of animals.
By relaying small electric pulses into specific regions, he made monkeys suddenly become lethargic and unresponsive to food and their young. Triggering signals to other areas of cats' brains, he prompted the animals to attack and kill rodents placed in front of them.
In his most famous experiment, he planted several electrodes into the brain of a fighting bull and sent a signal that stopped the bull dead in its tracks as it was rearing up to attack. When he switched the signal off, the bull resumed its aggressive behavior.
Today researchers have refined Delgado's and other's techniques, not simply to see how they can control their subjects, but to try and understand the functions of different regions of the brain. The studies have shown that one of the most powerful brain regions may be an area known as the reward center.
"This area that you're stimulating carries a signal that in effect says, 'Whatever you did just now was really good,'" explained Randy Gallistel, a professor of psychology and cognitive science at Rutgers University in New Jersey. "It's not a specific sensation, but an abstract one. And you can get animals to endure substantial pain to get it."
Peter Shizgal, a neuroscientist at Concordia University in Montreal, has shown that lab rats will almost always choose the reward brain stimulation over even the most tasty rat snack — a "milkshake" of cream and sugar and maple syrup. Other work has shown animals will walk over grates that deliver painful electric shocks to get to the trigger that delivers the stimulation.
Two years ago scientists used electrodes in rats' brains to activate their reward centers and effectively steer the rats to the left or right.
A tiny backpack on the rats acted as the pulse receiver. The researchers said the so-called "rat-bots" could someday carry cameras and help in the search for survivors.
Shizgal and Gallistel say stimulating the reward center and neighboring areas of the brain also holds potential for people.
Using brain stimulation to control appetite may be a possibility, as well as tapping similar therapy to get severe anorexics to eat. Obesity is a problem that affects more than a million people in the United States today. Brain stimulation would obviously be risky, but Gallistel argues people are already willing to undergo dangerous surgery to reduce the size of their stomachs in order to lose weight.
"It's dangerous to go into that area of the brain, but these people are already at risk," he said. "It's not at all crazy to think about."
If it's not crazy to think about using brain stimulation to gain or lose weight, then what about a Manchurian Candidate scenario of commanding a human being to kill another? Gallistel points out Delgado used brain stimulation to trigger cats to kill, so using the technology to command people may not be such a stretch.
"It's a very powerful stimulation that is very hard to resist. In general, you can produce spectacular motivation of all kinds by stimulating the brain in animals," he said. "There's no reason to think you couldn't produce spectacular motivation in humans."
Then again, Shizgal adds, even if something is possible, doesn't mean it's probable.
"A society that had the ability to grab you off the street and drill holes in your head is pretty unlikely," Shizgal said. "So brain control doesn't really keep me up at night."