A Review of Event‐Related Potential Components Discovered in the Context of Studying P3 a

In a seminal paper published in 1965, Sutton, Braren, Zubin and John first reported the P3 component recorded from the scalp of human subjects. The method used was to have subjects guess prior to each trial whether a randomly presented tone or flash of light would occur, and to have the subject discover whether the guess was correct or not when the stimulus for that trial was delivered. In another condition, the same stimulus was presented on all trials and the subject so informed. The result was that P3, a positive going wave with a peak latency of about 300 msec, was elicited when the subject was uncertain as to which stimulus would occur. Since the stimuli provided the subject with information concerning the correctness of the guess, Sutton et al. suggested that P3 was associated with information delivery. In a second study, Sutton, Tueting, Zubin and John (1967) presented one or two clicks, separated by 580 msec, on a random trial-by-trial basis. In addition, the clicks of a given trial were randomly loud or soft. In one condition, the subject guessed prior to each trial whether one or two clicks would be delivered. In another condition, the subject guessed whether the clicks would be loud or soft. Thus, in the first condition, the point in time when the subject learned the correctness of the guess was when the second click was, or was not, presented. It was found that the P3 was elicited by the second click and its absence. When guessing loudness, however, the subject learned the correctness of the guess when the first click was presented (the second click, if present, always had the same intensity as the first). In this condition, the presence or absence of the second click was not associated with P3. Hence, P3 was elicited by a stimulus (or the absence of a stimulus) that delivered relevant information.