A computer-generated three-dimensional functional atlas, based on clinical responses elicited upon electrical stimulation of subcortical structures of awake patients during stereotactic functional neurosurgery is presented, which shows a characteristic distribution pattern of motor, sensory and autonomic or emotional responses, respectively. The computer system used in this study is capable of accumulation and processing of data with three-dimensional coordinates, which can be converted to an anterior commissure-posterior commissure coordinate (AC-PC) system, and displays the processed data three-dimensionally together with a three-dimensional atlas created by interpolation of the Schaltenbrand-Bailey's atlas for standard anatomical landmarks.