11 Positive Slow Wave and P300: Association and Disassociation

Publisher Summary Slow Wave and P3b are members of a group of long latency, positive polarity, and endogenous event-related potential (ERP) components now known as the late positive complex (LPC). In the earliest experiments in which Slow Wave was found, it appeared that Slow Wave related to experimental variables in much the same manner as did P3b. As a result, during the early period there was little focus on Slow Wave. However, in recent years evidence for a behavioral dissociation between Slow Wave and P3b has been accumulating. The purpose of this chapter is, to review and attempt to evaluate the similarities and differences between Slow Wave and P3b. The initial reports of LPC activity described a single prominent component with a peak latency of about 300 msec. It was referred to as the late positive component or P3 or P300. Subsequent experiments established that P300 amplitude is generally largest over parietal scalp. P300 potentials have generally been elicited by events that are made relevant by serving various purposes: (1) to provide a subject with feedback information concerning the outcome of a prior task; (2) to be the object of a discrimination or counting task; (3) to be an imperative signal requiring performance of a motor response.