Damage to the insula is associated with abnormal interpersonal trust.

Area of Science:

• Neuroscience
• Social Psychology
• Behavioral Economics

Background:

• Reciprocal trust is fundamental for cooperation in social relationships.
• Previous studies suggest the insula's involvement in interpersonal trust.
• Neuropsychological insights into trust mechanisms are needed.

Purpose of the Study:

• To investigate the insula's role in reciprocal trust using a neuropsychological approach.
• To examine trust behaviors in individuals with insula damage during economic exchange.
• To elucidate the neural underpinnings of trust and social decision-making.

Main Methods:

• Utilized the Trust Game (TG), an economic exchange task.
• Compared trust behaviors of neurologically normal adults with individuals with insula damage.
• Employed a neuropsychological methodology to assess brain-behavior relationships.

Main Results:

• Neurologically normal adults demonstrated reciprocal trust, mirroring partner's trust levels.
• Individuals with insula damage exhibited abnormal trust expressions.
• Insula-damaged individuals showed misplaced trust as investors and trust violations as trustees.

Conclusions:

• The insula is crucial for the normal expression of interpersonal trust.
• Insula damage impairs the ability to recognize risk and social norm violations.
• Findings support the insula's role in regulating trust and cooperative behaviors.