P300 amplitude is determined by target‐to‐target interval

TLDR

P300 event‑related potentials are influenced by target probability, preceding nontargets, and interstimulus interval, all of which shape the target‑to‑target interval that modulates P300. The study aimed to assess how target‑to‑target interval influences P300 amplitude and latency by varying preceding nontargets and interstimulus intervals. The authors employed a variant of the oddball paradigm, manipulating the number of preceding nontargets (0–3) and ISI (1, 2, 4 s) to record P300 responses to auditory and visual stimuli. Increasing TTI increased P300 amplitude and decreased latency for both auditory and visual stimuli, with preceding nontargets exerting a stronger effect than ISI, confirming TTI as a critical determinant of P300 responsivity within a resource‑allocation framework.

Abstract

P300 event‐related brain potential (ERP) measures are affected by target stimulus probability, the number of nontargets preceding the target in the stimulus sequence structure, and interstimulus interval (ISI). Each of these factors contributes to the target‐to‐target interval (TTI), which also has been found to affect P300. The present study employed a variant of the oddball paradigm and manipulated the number of preceding nontarget stimuli (0, 1, 2, 3) and ISI (1, 2, 4 s) in order to systematically assess TTI effects on P300 values from auditory and visual stimuli. Number of preceding nontargets generally produced stronger effects than ISI in a manner suggesting that TTI determined P300 measures: Amplitude increased as TTI increased for both auditory and visual stimulus conditions, whereas latency tended to decrease with increased TTI. The finding that TTI is a critical determinant of P300 responsivity is discussed within a resource allocation theoretical framework.