ABSTRACT
Following the presentation of an auditory stimulus a series of electrical deflections, event-related potentials or ERPs, can be recorded from the scalp of humans and other animal species (Corwin, Bullock, & Schweitzer, 1982). ERPs have been widely used for monitoring human sensory and cognitive processing (Hillyard & Woods, 1979), and hold the promise of elucidating sensory and cognitive processes in other species (Bullock, 1981). In the human, short- and middle-latency auditory ERPs (latencies 1.5-30.0 msec) are exogenous in that their amplitudes and latencies are determined primarily by the characteristics of the evoking stimulus and are little affected by manipulations in processing strategy. In contrast, long-latency components change with attention and have been related to a variety of higher cognitive functions (Hillyard & Kutas, 1983). One of these components, the P3 or P300, is thought to be wholly endogenous, in that it reflects higher order optional cognitive operations which may be elicited by a stimulus (Donchin, 1981).
