Brain-computer music interface [BCMI]
- Anne Beetem Acker
Technology that allows a person to control a music-related output with commands expressed by brain signals. The output signal can control physical and virtual instruments and composition systems. Therapeutic applications include allowing severely physically disabled persons to participate actively in music-making. A number of methods of detecting and measuring brain activity have been tried; electroencephalography (EEG) has proved to be the most practical. Neural activity generates electric fields that can be detected by EEG electrodes placed on the scalp. The electrodes are placed in an array that allows mapping of neural activity over time. The signals are very weak and must be amplified and broken into frequency bands commonly labeled from low to high as Theta, Delta, Alpha, low Beta, medium Beta, and Gamma.
Three approaches are used for making music with BCMI. The most common approach, ‘direct sonification’, translates the EEG signal directly into sound; ‘musification’ translates the EEG signal by generating musical sequences based on the EEG behavior; ‘control’ detects specific EEG patterns produced by the subject to control music software. Alvin Lucier made the first known efforts at music performance with the EEG in the 1960s with his piece ‘Solo Performer’. He amplified the signals picked up from electrodes on his scalp, relaying them through loudspeakers directly coupled to percussion instruments including gongs, cymbals, tympani, and drums. David Rosenboom systematically studied the detection of human musical experience in EEG signals in the 1970s. A BCMI piano developed by Eduardo Miranda in ...