Testing the reinforcement learning hypothesis of social conformity

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Social Psychology

Background:

• Social conformity, influenced by others' opinions, engages brain regions like the posterior medial frontal cortex (pMFC), anterior insula, and striatum.
• These regions are also crucial for reinforcement learning, particularly in processing prediction errors.
• A hypothesis suggests a shared neural mechanism underlies both social conformity and reinforcement learning, though direct comparisons are lacking.

Purpose of the Study:

• To formally investigate and test the hypothesis of a common neural mechanism between social conformity and reinforcement learning.
• To directly compare the neural processes involved in social conformity and reinforcement learning using functional magnetic resonance imaging (fMRI).

Main Methods:

• Twenty-five participants completed both social conformity and reinforcement learning tasks while undergoing fMRI.
• Univariate fMRI analyses examined activation overlaps between conditions.
• Multivoxel pattern analysis (MVPA) was employed to assess the distinctiveness of neural patterns.

Main Results:

• Univariate analyses showed activation overlaps in the pMFC and bilateral insula for social conflict and unsigned prediction error.
• The striatum showed overlap between social conflict and signed prediction error.
• However, MVPA revealed largely distinct activation patterns between social conflict and prediction error across these regions.

Conclusions:

• Despite overlapping brain regions identified through univariate analysis, MVPA suggests that the neural mechanisms underlying social conformity and reinforcement learning are distinct.
• The study provides no clear evidence supporting a shared neural basis for social conformity and reinforcement learning.