The pre-supplementary motor area achieves inhibitory control by modulating response thresholds. (July 2022)

• Record Type: Journal Article
• Authors: Wolpe, Noham; Hezemans, Frank H.; Rae, Charlotte L.; Zhang, Jiaxiang; Rowe, James B.
• Is Part Of: Cortex. Volume 152(2022)
• Page Start: 98
• Page End: 108
• Publication Date: 2022-07
• Subjects: Pre-SMA -- Inhibitory control -- Voluntary action -- Bayesian hierarchical modelling -- Focal lesion; pre-SMA pre-supplementary motor area -- DDM Drift Diffusion Model -- SSRT Stop Signal Reaction Time -- RT Reaction Time; Neuropsychology -- Periodicals; Nervous system -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Behavior -- Periodicals; Neurology -- Periodicals; 612.825
• DOI: 10.1016/j.cortex.2022.03.018
• Languages: English
• ISSNs: 0010-9452

Abstract

Abstract: The pre-supplementary motor area (pre-SMA) is central for the initiation and inhibition of voluntary action. For the execution of action, the pre-SMA optimises the decision of which action to choose by adjusting the thresholds for the required evidence for each choice. However, it remains unclear how the pre-SMA contributes to action inhibition. Here, we use computational modelling of a stop/no-go task, performed by an adult with a focal lesion in the pre-SMA, and 52 age-matched controls. We show that the patient required more time to successfully inhibit an action (longer stop-signal reaction time) but was faster in terms of go reaction times. Computational modelling revealed that the patient's failure to stop was explained by a significantly lower response threshold for initiating an action, as compared to controls, suggesting that the patient needed less evidence before committing to an action. A similarly specific impairment was also observed for the decision of which action to choose. Together, our results suggest that dynamic threshold modulation may be a general mechanism by which the pre-SMA exerts its control over voluntary action.