Subjective and objective probability effects on P300 amplitude revisited

Abstract

Does objective probability affect P300 size independently and in addition to subjective probability? The latter was manipulated by the number of stimuli presented and classification task. Five groups saw target and frequent stimuli. Two saw these with p=.2 or .067, with two different button presses. Three groups saw two additional nontarget stimuli each with p=.067. One group pressed a different button for each stimulus. A second group pressed one button for the three oddballs, another for the frequent. A third critical group pressed one button for the target and another for other stimuli. In this group, P300 was larger for targets versus nontargets, and larger for nontargets versus frequents. Although nontargets were classified with frequents, their actual low probability distinguished them from frequents, and their subjective probability distinguished them from targets. Therefore, actual and subjective probability effects were independently found.

Electrophysiological differences in the processing of affective information in words and pictures

“…It should be remarked that in addition to affective significance, the LPC is sensitive to stimulus probability and rate of target occurrence (Polich, 2007;Rosenfeld, Biroschak, Kleschen, & Smith, 2005). Although LPC amplitude might be reduced in rapid serial presentation paradigms (Schupp et al, 2007), stimulus probability appears unlikely to explain the differential LPC findings for words and pictures in this study.…”

Frequency-domain analysis of fast oddball responses to visual stimuli: A feasibility study

“…8) is notable by itself, as it would not be expected from the notion that the P300 is related to the unexpectedness of the stimulus as determined by its subjective and objective probability (Duncan-Johnson and Donchin, 1977;Rosenfeld et al, 2005), or to the necessity for a "context update" (Donchin and Coles, 1988). The subjects realize very quickly that the stimulus sequence is fully predictable.…”

“…Subjective probability of the rare stimuli is considered to be a main determinant of the P300 amplitude (Duncan-Johnson and Donchin, 1977). Other factors include objective probability (Rosenfeld et al, 2005), and possibly environmental rareness .…”

The Role of Intention to Conceal in the P300-based Concealed Information Test

“…This might have been caused by use of the joker, a high salient stimulus, as the target card. It is known that P300 amplitudes for multiple stimuli are not determined by categories defined by the experimenter but by the categories perceived by a participant (Johnson and Donchin 1980;Rosenfeld et al 2005). When the target stimulus is highly salient, the other two stimuli are prone to be categorized as the same category, and the P300 amplitude difference between the two stimuli may become smaller (Katayama and Polich 1998).…”