Post-conventional moral reasoning is associated with increased ventral striatal activity at rest and during task

Area of Science:

• Neuroscience
• Moral Psychology
• Cognitive Science

Background:

• Moral reasoning varies significantly among individuals.
• Kohlberg's theory posits post-conventional moral reasoning relies on abstract principles.
• The frontostriatal reward system is implicated in prosocial behavior and moral judgments.

Purpose of the Study:

• To investigate the association between levels of moral reasoning and frontostriatal reward system function.
• To determine if individuals with post-conventional moral reasoning show distinct neural activity patterns.

Main Methods:

• Combined arterial spin labeling (ASL) perfusion and blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI).
• Measured frontostriatal reward system activity at rest and during a risky decision-making task.
• Analyzed data from 64 participants across different moral reasoning levels.

Main Results:

• Post-conventional reasoners displayed increased resting cerebral blood flow (CBF) in the ventral striatum and ventromedial prefrontal cortex.
• Resting CBF in these regions correlated with the degree of post-conventional thinking.
• Post-conventional individuals showed greater ventral striatal activation during risky decision-making.

Conclusions:

• Higher levels of post-conventional moral reasoning are linked to enhanced frontostriatal system activity.
• This association holds true for both resting-state and task-dependent neural function.
• Findings suggest a neural correlate for advanced moral cognition within the brain's reward circuitry.