Sometimes called neural-control interface (NCI), mind-machine interface (MMI), direct neural interface (DNI), or brain-machine interface (BMI), a brain-computer interface is a direct communication pathway between an enhanced or wired brain and an external device. A BCI allows for bidirectional information flow. BCIs are often in service of researching, mapping, assisting, augmenting, or repairing human cognitive or sensory-motor functions. The term BCI is often used to refer to an emerging technology domain where brain activity is used directly without any motor involvement to activate a computer or other external devices. The brain signals are usually measured using electroencephalography (EEG) and processed by neural interfaces.