Brain-Computer Interface

A system that reads electrical or other signals directly from the brain and translates them into commands for an external device, such as a computer cursor, a robotic arm, or a communication program, bypassing the body's own nerves and muscles. Signals can be gathered noninvasively from the scalp, most commonly by electroencephalography, or invasively from electrodes placed on or within the brain itself, with invasive systems generally offering a clearer signal at the cost of surgery. Early experimental systems in the 1970s and 1980s showed that a person could learn to control simple signals well enough to move a cursor or select letters, and research accelerated through the following decades as motorized wheelchairs, robotic limbs, and speech-generating software were connected to increasingly refined decoding software. The technology has been studied above all as a way to restore communication and control to people with severe paralysis or with conditions such as amyotrophic lateral sclerosis, who may retain little or no ability to move or speak but whose brain activity can still be read and interpreted.