Abstract: A system (10) for identifying brain activity, comprises a plurality of electrodes (14), said electrodes being arranged on a supporting structure (12) to be placed on a skull of a person, said electrodes (14) producing signals in accordance with the brainwaves of said person, amplifying means for amplifying the electrical signals sensed by said electrodes, data processing means (26) for processing said amplified signals, identifying a specific mental state from said signals and generating a signal indicative of said recognised mental state, and transmitter means for transmitting a signal corresponding to said identified mental state to a computer (22).