Mindfulness training modulates value signals in ventromedial prefrontal cortex through input from insular cortex.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Decision Science

Background:

• Ventromedial prefrontal cortex (vmPFC) value signals are influenced by top-down cognitive inputs like monetary incentives.
• Mindfulness training (MT) is hypothesized to enhance control over these top-down influences, but direct evidence is lacking.

Purpose of the Study:

• To investigate the behavioral and neural effects of 8-week mindfulness training on vmPFC value signals.
• To determine if MT modulates biases related to monetary favors and primary rewards.
• To explore the neural mechanisms underlying MT's impact on value computation.

Main Methods:

• A randomized longitudinal design assessed 8 weeks of MT in naive subjects.
• Two paradigms were used: primary reward conditioning (fruit juice) and a monetary favor bias task (art viewing).
• Functional connectivity analyses examined vmPFC coupling with other brain regions, comparing MT with an active control (ACT).

Main Results:

• MT behaviorally reduced the top-down bias of monetary favors, impacting vmPFC value signals.
• MT modulated vmPFC value signals in response to primary rewards.
• Active control training (ACT) produced similar behavioral effects via vmPFC signal changes.
• Functional connectivity revealed vmPFC coupling with the posterior insula in MT groups, but not ACT groups.

Conclusions:

• Mindfulness training effectively censors top-down biases in value signals within the vmPFC.
• MT's effects on value computation involve integration of interoceptive input from the insular cortex.
• These findings suggest MT enhances regulatory control over both primary and secondary reward processing.