Event Abstract Back to Event Prestimulus EEG Effects on ERPs in a Variable ISI Equiprobable Go/NoGo Task Diana Karamacoska1*, Robert J. Barry1 and Frances M. De Blasio1 1 University of Wollongong, Australia Aim The effects of prestimulus electroencephalographic (EEG) activity on event-related potentials (ERPs) have been studied extensively in a variety of tasks involving fixed interstimulus intervals (ISIs). These EEG-ERP relationships have yet to be examined when the task stimuli are presented with temporal uncertainty, or at a between-subjects level. The aim of the current study was to investigate the between-subjects influence of prestimulus delta, theta, alpha, beta, and gamma activity on ERPs in a variable ISI equiprobable Go/NoGo task. Method Continuous EEG was recorded from 32 participants as high and low tones were randomly presented binaurally, with 1-1.5 second ISIs, and a button press was required to the designated Go stimulus. Pre- and post-stimulus data were epoched, and Fast Fourier Transformations were applied to extract the average prestimulus EEG band activity of each participant. Principal components analysis was used to extract the first five poststimulus factors as ERP components, at their sites of maximal activity. Correlations assessed the EEG-ERP amplitude relationships in this task. Results Greater prestimulus delta and theta activity directly increased N1-1 negativity, particularly for Go stimuli. There were no effects of alpha. Higher levels of beta similarly augmented N1-1 amplitudes for Go, and modulated Go P2 and P3b positivities in a U-shaped pattern, and the NoGo P2 in an inverted-U shape. Larger prestimulus gamma levels increased the negativity of the N1-1 and P2. Conclusion Overall, there was an augmenting effect of prestimulus EEG levels on sensory processes that was more specific to the task-relevant Go stimulus. These findings offer novel interpretations to explain the ERP amplitude shifts in variable ISI tasks that were previously attributed to temporal uncertainty alone. The higher-frequency bands were found to modulate the endogenous components differentially between the stimulus types, consistent with previous findings concerning EEG effects on cognitive processes. Keywords: Prestimulus EEG, Principal Components Analysis (PCA), temporal uncertainty, event-related potentials (ERPs), Auditory Go/NoGo, Interstimulus interval (ISI) Conference: Australasian Society for Psychophysiology, Inc, Coffs Harbour, Australia, 26 Nov - 28 Nov, 2014. Presentation Type: Oral Presentation Topic: Psychophysiology Citation: Karamacoska D, Barry RJ and De Blasio FM (2014). Prestimulus EEG Effects on ERPs in a Variable ISI Equiprobable Go/NoGo Task. Conference Abstract: Australasian Society for Psychophysiology, Inc. doi: 10.3389/conf.fnhum.2014.216.00021 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Oct 2014; Published Online: 02 Dec 2014. * Correspondence: Miss. Diana Karamacoska, University of Wollongong, Wollongong, Australia, d.karamacoska@westernsydney.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Diana Karamacoska Robert J Barry Frances M De Blasio Google Diana Karamacoska Robert J Barry Frances M De Blasio Google Scholar Diana Karamacoska Robert J Barry Frances M De Blasio PubMed Diana Karamacoska Robert J Barry Frances M De Blasio Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.