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Selection and inhibition mechanisms for human voluntary action decisions

Jiaxiang Zhang Orcid Logo, Laura E. Hughes, James B. Rowe

NeuroImage, Volume: 63, Issue: 1, Pages: 392 - 402

Swansea University Author: Jiaxiang Zhang Orcid Logo

Abstract

One can choose between action alternatives that have no apparent difference in their outcomes. Such voluntary action decisions are associated with widespread frontal–parietal activation, and a tendency to inhibit the repetition of a previous action. However, the mechanism of initiating voluntary act...

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Published in: NeuroImage
ISSN: 1053-8119
Published: Elsevier BV 2012
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa61336
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Abstract: One can choose between action alternatives that have no apparent difference in their outcomes. Such voluntary action decisions are associated with widespread frontal–parietal activation, and a tendency to inhibit the repetition of a previous action. However, the mechanism of initiating voluntary actions and the functions of different brain regions during this process remains largely unknown. Here, we combine computational modeling and functional magnetic resonance imaging to test the selection and inhibition mechanisms that mediate trial-to-trial voluntary action decisions. We fitted an optimized accumulator model to behavioral responses in a finger-tapping task in which participants were instructed to make chosen actions or specified actions. Model parameters derived from each individual were then applied to estimate the expected accumulated metabolic activity (EAA) engaged in every single trial. The EAA was associated with blood oxygenation level-dependent responses in a decision work that was maximal in the supplementary motor area and the caudal anterior cingulate cortex, consistent with a competitive accumulation-to-threshold mechanism for action decision by these regions. Furthermore, specific inhibition of the previous action's accumulator was related to the suppression of response repetition. This action-specific inhibition correlated with the activity of the right inferior frontal gyrus, when the option to repeat existed. Our findings suggest that human voluntary action decisions are mediated by complementary processes of intentional selection and inhibition.
Keywords: Decision making; Inhibition; Volition; Accumulation; fMRI; Modeling
College: Faculty of Science and Engineering
Funders: This work was supported by Medical Research Council intramural program (MC-A060-5PQ30) and the Welcome Trust (088324).
Issue: 1
Start Page: 392
End Page: 402