Social Observation Increases Functional Segregation between MPFC Subregions Predicting Prosocial Consumer Decisions

Area of Science:

• Neuroscience
• Social Psychology
• Neuroeconomics

Background:

• The observer effect, where social presence influences behavior, is well-documented.
• However, the neural mechanisms driving the observer effect in prosocial behavior remain largely unexplored.
• Previous research indicates social observation can enhance ethical consumption.

Purpose of the Study:

• To investigate the neural underpinnings of the observer effect on prosocial behavior in ethical consumption.
• To identify brain regions involved in value-based decision-making for social versus non-social products under observation.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to monitor brain activity.
• Participants made purchasing decisions for social and non-social products under conditions of social observation and control.
• Analysis focused on activity in prefrontal cortex subregions and their functional connectivity.

Main Results:

• The anterior cingulate cortex (ACC) and dorsomedial prefrontal cortex (dmPFC) encoded subjective values for social and non-social products, respectively, during observation.
• The ACC demonstrated functional coupling with the amygdala and anterior insula during observed prosocial purchasing decisions.
• Ventromedial prefrontal cortex (vmPFC) activity correlated with faster reaction times and increased prosocial behavior, irrespective of observation.

Conclusions:

• Subregions of the medial prefrontal cortex (mPFC), including dmPFC, ACC, and vmPFC, play hierarchical roles in processing decision values.
• These regions differentiate between reputation-based value (under observation) and internalized prosocial value.
• Findings elucidate the neural basis of how social observation modulates ethical consumption and prosocial decision-making.