The Ultimate Remote Control; One day, our brains might be able to beam our very thoughts wirelessly to the machines around us.(Cover Story)

Byline: Carl Zimmer

Wireless technology lets us talk on cell phones with people thousands of miles away, surf the Web without a cable and control our stereos, DVD players and televisions. But none of this technology works without pushing buttons or giving voice commands. Imagine what it would be like if we could turn our brains into remote controls, sending wireless commands to computers, robots and other machines.

It's not so farfetched. Like a computer, the brain is made up of many little units wired together to process information digitally. Where computers use zeros and ones, neurons encode our thoughts in all-or-nothing electrical impulses. And if computers and brains speak the same language, it should be possible for the two to speak to each other.

Researchers hope ultimately to eavesdrop on the brain's digital crackle with electrodes, transmit those signals to a computer that can read the brain's code and then use those signals to control a machine. Imagine a quadriplegic person able to operate a robotic arm mounted on a wheelchair with merely a thought. Imagine a digital stream flowing from a microphone into a deaf person's auditory cortex, where it could become the perception of sound.

These dreams have an official name: brain-machine interfaces. A decade ago they seemed little more than fantasy, but now their emergence seems like just a matter of time. At the Center for Neuroengineering at Duke University, monkeys with electrodes surgically implanted in their brains move robotic arms with their minds alone. The electrodes pick up signals from neurons that normally would produce hand movements, and a computer translates those instructions into commands that drive the robot. The translation happens almost instantaneously, and is sophisticated enough to allow the monkey to do more than move the arm. It can also squeeze the gripper at the end of the robotic arm as hard or as lightly as it pleases.

The Duke neuroengineers are now moving from monkeys to people. In the July 2004 issue of the Journal of Neurosurgery, they report their success at temporarily implanting their electrodes into the brains of volunteers. (The subjects were undergoing surgery for Parkinson's disease and other tremor disorders.) The patients then played videogames while the electrodes recorded the brain signals. The scientists trained a computer to ...