Brain-activated technology. Researchers monitoring the progress of a simulated flight in which the simulator is 'steered' by brain activity. To the side of the cockpit computer screen are lights flashing at 13 Hz (cycles per second). This sets up a similar pattern of activity in the pilot's brain. The pilot, trained using biofeedback techniques, is able to amplify or suppress the brain's response to the lights. The brain activity is detected by electrodes in a special cap. The simulator interprets raised activity as 'turn right', suppressed activity as 'turn left', and normal activity as 'fly level'. Photographed at Wright-Patterson Air Force Base, USA, in 1994.