The Lateralized Readiness Potential

When we respond with one hand, a negative potential can be observed over the motor cortex contralateral to the responding hand. This lateralized readiness potential (lrp) starts even before the response is emitted, and its onset has been taken as a measure of the time at which the brain began preparing to make the response. The lrp has also been used to measure the preliminary activation of a response that is never actually produced. The lrp is a valuable measure of relatively central response activation that is now widely used in many areas of psychology involving reaction time tasks. This chapter discusses the definition of lrp, methods of isolating lrp from other components, brain systems generating the lrp, uses of lrp, and analyses of lrp.