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Multiple Late Positive Potentials in Two Visual Discrimination Tasks
Author(s) -
Friedman David,
Vaughan Herbert G.,
ErlenmeyerKimling L.
Publication year - 1981
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.1981.tb01838.x
Subject(s) - psychology , varimax rotation , task (project management) , principal component analysis , event related potential , cognitive psychology , audiology , discriminative model , analysis of variance , developmental psychology , speech recognition , pattern recognition (psychology) , electroencephalography , statistics , artificial intelligence , neuroscience , psychometrics , computer science , mathematics , cronbach's alpha , management , economics , medicine
Event‐related potentials (ERPs) were recorded from 30 adolescents during two versions of the continuous performance test (CPT). Task B involved more complex processing than Task A, because subjects were required to store and compare successive stimuli to determine if a target had occurred, while Task A required a simple match‐mismatch decision. This was corroborated behaviorally, with Task B producing greater error rate, longer reaction times, and greater reaction time variance than Task A. Principal Components Analysis (PCA) with Varimax rotation was performed separately on the signal (SIG) and non‐signal (NSIG) ERPs from each task to objectively verify the presence of multiple positive peaks which had been visually identified in the individual and grand mean waveforms. These PCAs yielded factor structures and “components” whose shapes, time courses and factor score topographies were similar across ERP subsets, suggesting that each might represent activity within the same brain region. Differences in these factors across data sets were also evident. To assess these, ANOVAs of the factor scores from the PCA performed on the ERPs pooled across stimuli and tasks were performed. Consistent between‐task effects were shown by P450, P550 and slow wave, potentials which appear to reflect processes related to the discriminative outcome. These data conclusively demonstrate the presence of multiple late positive components within the latency range of the classical P300 wave.