Brain-Computer Interfaces

Brain implants have been used by thousands of people to monitor brain activity during epileptic seizures. But some volunteers have also let researchers use their implants to observe their brains as they talked, moved their hands, and so on. When connected to a computer, the implants could be used to move animated hands, or even decode words the volunteers were silently thinking. Several devices that connect people's brains to computers have already been developed for medical use, and many more potential brain-computer interfaces are being explored.

How it Works

Doctors have already connected electronic devices to people's brains that allow blind people to see and deaf people to hear. Cameras and microphones send electronic messages that stimulate neurons to send signals to the brain. The brain perceives these signals as images and sounds, just as if they came from a healthy eye or ear. Neurons can communicate directly with computers because both can send and receive electric impulses.

Retinal implants that enable vision in blind people are not ubiquitous... yet. But cochlear implants--devices that connect microphones to the brain--have already been installed in more than 70,000 people, enabling hearing in thousands of deaf people.

Today, these devices are used to replace lost senses. But theoretically, any sounds and images could be sent into the brain. The camera could be anywhere, including an airplane. Or it could transmit a recording, not a live image. The images would not even have to come from a camera--the same technology could potentially transmit images from movies, video games, computers, or the Internet.