Event-related-potential (ERP) reflections of mental resources: a review and synthesis.

In this review studies are evaluated that have utilized middle-latency and late components of the event-related potential (ERP) as indices of the activation of processing resources. Processing resources are defined as energetical systems that modulate cognitive processes or data processing systems. An essential element of the resource conceptualization is the idea that processing structures receive not only information input but also input from these energetical systems. It is argued further that the principal role of these systems is to provide the 'gain' for the data processing systems. In reviewing these studies special attention is paid to factors affecting the amplitude of ERP components in single- and dual-task studies, and to the inferences that can be drawn about which particular types of processing resources are reflected in these changes in component amplitudes. Finally, a working model is presented relating middle-latency and late ERP components to specific perceptual, perceptual-central and central processing resources.