His early research with Hans Helmut Kornhuber in the mid sixties led to the discovery Bereitschaftspotential or readiness potential , which is a measure of neural activity in the brain that precedes voluntary movements - set an important standard in research and rehabilitation of motor control systems .
His early research with Hans Helmut Kornhuber in the mid sixties led to the discovery of the Bereitschaftspotential ( or readiness potential ) , which is a measure of neural activity in the brain that precedes voluntary movements . 
 This discovery set an important standard in research and rehabilitation of motor control systems .