APA Dictionary of Psychology

a system that translates the electrical activity of the brain into signals controlling external displays and devices, such as cursors on computer screens, Internet browsers, robotic arms, switches, or prostheses. This muscle-independent arrangement aims to help people with motor functions severely limited by injuries, progressive neurodegenerative diseases, or other conditions (e.g., locked-in syndrome) to communicate, manipulate objects in the environment, and otherwise enhance their independence and quality of life. BCI technology generally relies on changes in particular aspects of user-specific electroencephalographic rhythms, including the P3 component, sensorimotor rhythms, slow cortical potentials, and visual evoked potentials. Some interfaces, however, are based on other types of electrophysiological activity that require different measurement techniques (e.g., electrocorticography, functional magnetic resonance imaging, magnetoencephalography). Also called brain–machine interface (BMI).