All it took was a few jolts of electricity to turn ordinary rats into roborats and for pundits to leap to the conclusion that ordinary humans will soon be transformed into robohumans. Scientists at the State University of New York Downstate Medical Center in Brooklyn sparked a media frenzy two years ago when they demonstrated that rats with electrodes implanted in their brains could be steered like remote-controlled toy cars through an obstacle course. Using a laptop equipped with a wireless transmitter, a researcher stimulated cortical cells governing whisker sensations and reinforced those signals by zapping the rats' pleasure centers. Presto! With this simple setup, the team had created living robots.
Publications around the world proclaimed the imminence of those familiar science-fiction staples, surgically implanted devices that electronically monitor and manipulate our minds. The Economist warned that neurotechnology may be on the verge of "overturning the essential nature of humanity," and New York Times columnist William Safire brooded that neural implants might allow a "controlling organization" to hack into our brains. In a more positive vein, MIT's artificial-intelligence maven Rodney Brooks predicted in Technology Review that by 2020 implants will let us carry out "thought-activated Google searches."
Hollywood's remake of The Manchurian Candidate raises the specter of a remote- controlled soldier turned politician. In fact, officials at the Defense Advanced Research Projects Agency, which funds the roborat team, have suggested that cyborg soldiers could control weapons systems—or be controlled—via brain chips. "Implanting electrodes into healthy people is not something we're going to do anytime soon," says Alan Rudolf, the former head of the DARPA brain-machine research program. "But 20 years ago, no one thought we'd put a laser in the eye. This agency leaves the door open to what's possible."
Of course, that begs the question: Just how realistic are these futuristic scenarios? To achieve truly precise mind reading and control, neuroscientists must master the syntax or set of rules that transform electrochemical pulses coursing through the brain into perceptions, memories, emotions, and decisions. Deciphering this so-called neural code—think of it as the brain's software—is the ultimate goal of many scientists tinkering with brain-machine interfaces. "If you're a real neuroscientist, that's the game you want to play," says John Chapin, a coleader of the roborat research team.
Chapin ranks the neural code right up there with two other great scientific mysteries: the origin of the universe and of life on Earth. The neural code is arguably the most consequential of the three. The solution could, in principle, vastly expand our power to treat ailing brains and to augment healthy ones. It could allow us to program computers with human capabilities, helping them become more clever than HAL in 2001: A Space Odyssey and C-3PO in Star Wars. The neural code could also represent the key to the deepest of all philosophical conundrums—the mind-body problem. We would finally understand how this wrinkled lump of jelly in our skulls generates a unique, conscious self with a sense of personal identity and autonomy.
