Brain-activated technology. A computer maze used by brain-activated technology researchers, in which brain activity is used to control the cursor (upper right). The subject, trained using biofeedback techniques, is able to alter the pattern of various brain waves. The patterns, a combination of electroencephalogram (EEG) and electromyogram (EMG) signals, are detected by electrodes on the subject's head, and are interpreted by a computer as simple commands such as 'move left' or 'move down'. The subject is then able to negotiate the cursor through a maze on the screen. Photographed at Brain Actuated Technologies Inc, Ohio, USA.