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Is the target‐to‐target interval a critical determinant of P3 amplitude?
Author(s) -
Gonsalvez Craig J.,
Gordon Evian,
Grayson Sandra,
Barry Robert J.,
Lazzaro Illario,
Bahramali Homayoun
Publication year - 1999
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/1469-8986.3650643
Subject(s) - interstimulus interval , psychology , interval (graph theory) , audiology , amplitude , oddball paradigm , communication , event related potential , mathematics , cognition , neuroscience , combinatorics , physics , optics , medicine , stimulation
The P3 amplitude is augmented by decrements in target‐probability, increments in the number of nontargets preceding the target, and extensions of the interstimulus interval (ISI). Each of these changes prolongs the target‐to‐target interval (TTI) and, consequently, results attributed to these factors might, at least partially, be accounted for by the TTI. Recent research also indicates that the P3s elicited by targets in one‐, two‐, and three‐stimuli tasks (in which the TTI remains invariant) are similar. However, the TTI has not been examined systematically in previous research. The present study had subjects listen to a randomized ISI (0.5, 1, 2, or 4 s) version of the auditory oddball task in which targets occurred after one, two, three, four, or five nontargets. Event‐related potentials were analyzed based on ISI, sequential structure, and TTI. The study examined sequence and ISI effects independent of TTI effects and demonstrated that extensions of ISI affected N1 but not P3 amplitude, extensions of TTI enhanced P3 amplitude independent of sequential structure, and sequential structure failed to influence P3 amplitude when TTI was controlled.