Problems and paradigms in ERP research.

The ERP technique may provide noninvasive measures that are associated with the processing of psychological information during the performance of a task. Some investigators even regard ERPs as direct manifestations of the psychological processes induced by the demands of the task. Before such a strong claim can be made several methodological problems must be resolved. The present paper discusses the definition and identification of the endogenous components in the ERP, the separation of endogenous components from exogenous components, and the different ways in which inferences can be made about psychological processes on the basis of ERP measures.