Generous economic investments after basolateral amygdala damage

Area of Science:

• Neuroscience
• Social Psychology
• Behavioral Economics

Background:

• Human social decision-making is modeled by instrumental and impulsive behaviors.
• The amygdala's role in social-economic behavior is not well understood.
• Rodent studies implicate the basolateral amygdala (BLA) in instrumental behaviors and the central-medial amygdala in impulsive behaviors.

Purpose of the Study:

• To investigate the function of the human basolateral amygdala (BLA) in social-economic decision-making.
• To determine if selective BLA damage impacts instrumental and impulsive social behaviors.

Main Methods:

• Studied humans with selective BLA damage and a functional central-medial amygdala.
• Utilized a trust game to assess social-economic investments.
• Conducted non-social risk-taking tasks to control for general risk preferences.

Main Results:

• BLA-damaged individuals invested nearly 100% more money in unfamiliar others compared to controls.
• Generosity in BLA-damaged subjects was not linked to general risk-taking tendencies.
• These subjects did not expect higher returns or perceive others as more trustworthy, indicating non-instrumental generosity.

Conclusions:

• Selective human BLA damage impairs instrumental social-economic decision-making.
• The human BLA is essential for instrumental behaviors in social contexts.
• Findings suggest a translation of rodent amygdala function to human social behavior.