A closed-loop brain-computer music interface for continuous affective interaction

Research on human emotions and underlying brain processes is mostly performed open-loop, e.g. by presenting emotional stimuli and measuring subject's brain responses. Investigating human emotions in interaction with emotional stimuli (closed-loop) significantly complicates experimental setups and has so far rarely been proposed. We present concept and technical realization of an electroencephalography (EEG)-based affective Brain-Computer Interface (BCI) to study emotional brain processes in continuous closed-loop interaction. Our BCI consists of an algorithm generating continuous patterns of synthesized affective music, embedded in an online BCI architecture. An initial calibration is employed to obtain user-specific models associating EEG patterns with affective content in musical patterns. These models are then used in online application to translate the user's affect into a continuous musical representation; playback to the user results in closed-loop affective brain-interactions. The proposed BCI provides a platform to stimulate the brain in a closed-loop fashion, offering novel approaches to study human sensorimotor integration and emotions.