Social Risk Coding by Amygdala Activity and Connectivity with the Dorsal Anterior Cingulate Cortex

Area of Science:

• Neuroscience
• Social Psychology
• Decision Science

Background:

• Risk is crucial for economic decisions, yet its neural basis in social contexts remains unclear.
• The amygdala and dorsal anterior cingulate cortex (dACC) are implicated in risk-taking behaviors.
• Understanding social risk processing is vital for comprehending human economic behavior.

Purpose of the Study:

• To investigate how risk, defined as reward probability variance, influences decisions and neural activity in social contexts using fMRI.
• To explore the neural correlates of social risk aversion and its relationship with decision-making.
• To determine if social risk processing in the brain differs from nonsocial risk processing.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity in 20 human volunteers.
• Participants made decisions involving social and nonsocial outcomes with varying reward probabilities.
• A Becker-DeGroot-Marschak auction-like procedure estimated participants' aversion to social risk.

Main Results:

• The amygdala showed distinct signals for social and nonsocial risk, increasing with reward variance in both domains.
• 75% of participants exhibited aversion to social risk.
• Greater social risk aversion was associated with decreased functional coupling between amygdala and dACC, specifically for social risk.

Conclusions:

• The amygdala and its coupling with dACC are involved in processing both objective and subjective social risk.
• Social risk is processed distinctly from nonsocial risk within the amygdala.
• Findings suggest a separate neural mechanism for social risk evaluation compared to nonsocial risk, despite theoretical frameworks aligning them.