Ventromedial Prefrontal Cortex Activity and Sympathetic Allostasis During Value-Based Ambivalence

Area of Science:

• Neuroscience
• Decision Science
• Autonomic Nervous System

Background:

• Anxiety involves low confidence and high stress, linked to fear generalization and altered decision-making.
• The ventromedial prefrontal cortex (vmPFC) is crucial for approach-avoidance decisions and connects to the sympathetic nervous system.
• The role of vmPFC in rapid stress responses during decision-making under uncertainty is not well understood.

Purpose of the Study:

• To investigate the interplay between sympathetic cardiac stress responses, vmPFC activity, and decision-making behavior.
• To examine how these factors change across different time scales (minutes vs. trial-to-trial).

Main Methods:

• Utilized an approach-avoidance task with monetary rewards and electric shock stimuli.
• Collected concurrent functional magnetic resonance imaging (fMRI), electrocardiography (EKG), and impedance cardiography to measure vmPFC activity and sympathetic drive.
• Employed a trial-to-trial General Linear Model (GLM) for short-timescale analysis.

Main Results:

• Increased sympathetic drive over minutes correlated with reduced decision ambivalence, indicating "mobilization" for consistent value-action mapping.
• Increased vmPFC activity during low-ambivalence decisions was associated with decreased sympathetic state on shorter timescales.
• Findings suggest sympathetic drive resolves decision ambivalence over longer periods, with vmPFC potentially modulating this on a moment-to-moment basis.

Conclusions:

• Sympathetic drive plays a role in resolving decision ambivalence over extended periods.
• The ventromedial prefrontal cortex (vmPFC) may modulate sympathetic responses during decision-making on a moment-to-moment basis.
• This research sheds light on the neural and physiological mechanisms underlying anxiety and decision-making under stress.