On the relationship of P3a and the Novelty-P3.
Deviant stimuli give rise to a late positive ERP component with latencies from 250 to 400 ms. Target deviants elicit a P300 with maximum amplitude over parieto-central recording sites while the 'P300' elicited by deviant nontarget stimuli occurs somewhat earlier and shows a more frontally-oriented scalp distribution. Two varieties of frontal P300s have been described, elicited either by rare stimuli (target or nontarget) presented in a two-stimulus oddball task (P3a) or by infrequent, unrecognizable stimuli presented in the context of a three-stimulus oddball task (Novelty-P3). The Novelty-P3 has been observed in a number of subsequent studies; the P3a has not been extensively studied and both its significance and existence have been called into question. The present report describes a replication of two prototypical studies with 'frontal' P3s observed in each context. Application of factor analysis to the two sets of ERP waveforms does not support a distinction between these two components.
Simons
R F
RF
Department of Psychology, University of Delaware, Newark, DE 19716, USA. rsimons@udel.edu
Graham
F K
FK
Miles
M A
MA
Chen
X
X
D000328:Adult; D001921:Brain / Q000502:physiology; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005163:Factor Analysis, Statistical; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D013647:Task Performance and Analysis