Distinct neural circuits support incentivized inhibition.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuroimaging

Background:

• Incentivized inhibition is crucial for adaptive impulse control.
• The right ventrolateral prefrontal cortex (VLPFC) is implicated in response inhibition.
• The influence of incentives on VLPFC circuits for inhibition requires further investigation.

Purpose of the Study:

• To characterize neural circuits supporting incentivized inhibition using a multimodal approach.
• To investigate how incentives modulate response inhibition and associated neural activity.
• To explore the structural and functional connectivity between key brain regions involved in incentivized inhibition.

Main Methods:

• Utilized a novel behavioral task combined with functional magnetic resonance imaging (fMRI) and diffusion-weighted imaging (DWI).
• Assessed behavioral responses, neural activity (fMRI), and white-matter tract integrity (DWI).
• Employed statistical mediation analyses to link structural, functional, and behavioral data.

Main Results:

• Large incentives increased response drive but decreased response inhibition behaviorally.
• Activity in the right VLPFC and right anterior insula (AIns) predicted successful inhibition under high incentives.
• A novel white-matter tract connecting the right AIns and VLPFC was identified, with its coherence correlating with incentivized inhibition performance.
• Individual differences in right VLPFC activity mediated the relationship between AIns-VLPFC tract coherence and performance.

Conclusions:

• Multimodal findings integrate brain structure, function, and behavior to explain incentivized inhibition.
• The right AIns-VLPFC pathway and its integrity are critical for maintaining impulse control under high stakes.
• Individual VLPFC activity levels play a mediating role in how structural connectivity influences high-stakes inhibition.