The effect of congruent vs. incongruent distractor positioning on electrophysiological signals during perceptual decision-making

Wongtrakun, Jaeger, Zhou, Shou-Han, Bellgrove, Mark A., Chong, Trevor T.-J. and Coxon, James P. 2024. The effect of congruent vs. incongruent distractor positioning on electrophysiological signals during perceptual decision-making. The Journal of Neuroscience 44 (45) , e2079232024. 10.1523/JNEUROSCI.2079-23.2024

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Abstract

Key event-related potentials (ERPs) of perceptual decision-making such as the centroparietal positivity (CPP) elucidate how evidence is accumulated towards a given choice. Furthermore, this accumulation can be impacted by visual target selection signals such as the N2 contralateral (N2c). How these underlying neural mechanisms of perceptual decision-making are influenced by the spatial congruence of distractors relative to target stimuli remains unclear. Here, we used electroencephalography (EEG) in humans of both sexes to investigate the effect of distractor spatial congruency (same vs. different hemifield relative to targets) on perceptual decision-making. We confirmed that responses for perceptual decisions were slower for spatially incongruent vs. congruent distractors of high salience. Similarly, markers of target selection (N2c peak amplitude) and evidence accumulation (CPP slope) were found to be lower when distractors were spatially incongruent vs. congruent. To evaluate the effects of congruency further, we applied drift diffusion modelling to participant responses, which showed that larger amplitudes of both ERPs were correlated with shorter non-decision times when considering the effect of congruency. The modelling also suggested that congruency’s effect on behaviour occurred prior to and during evidence accumulation when considering the effects of the N2c peak and CPP slope. These findings point to spatially incongruent distractors, relative to congruent distractors, influencing decisions as early as the initial sensory processing phase, then continuing to exert an effect as evidence is accumulated throughout the decision-making process. Overall, our findings highlight how key electrophysiological signals of perceptual decision-making are influenced by the spatial congruence of target and distractor.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Engineering
Publisher:	Society for Neuroscience
ISSN:	0270-6474
Date of First Compliant Deposit:	1 October 2024
Date of Acceptance:	6 September 2024
Last Modified:	18 Dec 2024 15:00
URI:	https://orca.cardiff.ac.uk/id/eprint/172308

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