APA Dictionary of Psychology

an electrical brain potential that precedes volitional muscular movement. It is detectable some 500 to 600 ms before motion occurs. Also called Bereitschaftspotential (BP). See predecisional negative shift. See also lateralized readiness potential; event-related potential. [first reported in 1964 by German neurologists Hans Helmut Kornhuber and Lüder Deecke (1938–  )]