Vertex potentials evoked during auditory signal detection: Relation to decision criteria

Abstract

Vertex potentials were recorded from eight Ss performing in an auditory threshold detection task with rating scale responses. The amplitudes and latencies of both the N 1 and the late positive (P3) components were found to vary systematically with the criterion level of the decision. These changes in the waveshape of the N 1 component were comparable to those produced by varying the signal intensity in a passive condition, but the late positive component in the active task was not similarly related to the passively evoked P2 component It was suggested that the Nl and P3 components represent distinctive aspects of the decision process, with N 1 signifying the quantity of signal information received and P3 reflecting the certainty of the decision based upon that information.

Vertex evoked potentials in a rating-scale detection task: relation to signal probability

“…In agreement with previous studies (Iillyard et al, 1971;Paul and Sutton, 1972;Squires et al, 1973b), the amplitude of the P3 component of the auditory evoked potential associated with correct detections of threshold-level signals (HITs) was found to 'be systematically related to the strictness of the response criterion. A lhighly confident, high-criterion HIT was associated with a large P3 component of relatively short latency, and for decreasingly confident detections the amplitude of that component decreased while its latency increased.…”

“…As shown previously (Squires et al, 1973b), the highest confidence HliT (a rating of 1, signal In Figure 3 the P3 amplitude decreases with decreasing confidence rating for 1-111'Ts at all three signal probabilities. A given numerical rating at a low signal probability, however, has a higher criterion cutoff (as defined by the z. value) than the same rating with a high signal proban bility.…”

“…This was to be expected if, as suggested previously (Squires et al, 1973b), the amplitude of Nl reflects the effective intensity of the stimulus.…”

“…In a subsequent elaboration (Squires, Hlillyard, and Lindsay, 1973a), it was postulated that internal neural models or "templates" were established for the purpose of recognizing each of the relevant stimulus alternatives; stimulus recognition then engenders a P3 wave that increases with the confidence of the recognition (i.e. , 1972), particularly when those correct rejections are made with a high degree of confidence (Squires et al, 1973b) or are very improbable . This absence of a P3 component for correct rejections in a threshold situation is especially puzzling in light of the aforementioned reports that P3 waves do accompany task-relevant omissions of suprathreshold signals (c.f.…”

Brain potentials reflect residual face processing in a case of prosopagnosia

“…The parieto-central P300 (or P3b for short) is larger for informative trials (especially when something unexpected occurs) and is only generated when active attention is given to the stimuli (Picton, 1992;Ruchkin, Johnson, Canoune, Ritter, & Hammer, 1990). The amplitude of P3b is directly related to the subject's confidence in his decisions (K. C. Squires, Hillyard, & Lindsay, 1973). Although debated (see Donchin & Coles, 1988;Verleger, 1988), an accepted interpretation is that P3b reflects the updating of working memory with respect to explicitly recognised stimuli.…”