The caudate signals bad reputation during trust decisions

Area of Science:

• Neuroscience
• Social Psychology
• Decision Science

Background:

• Trust is essential for well-being and is influenced by reputation.
• Neural mechanisms underlying reputation-based trust decisions are not well understood.

Purpose of the Study:

• To investigate the neural basis of reputation signaling during trust decisions.
• To examine how the brain integrates reputation information acquired through direct interaction.

Main Methods:

• Event-related functional magnetic resonance imaging (fMRI) was used.
• Participants played an iterated Trust Game with partners of varying known reciprocation rates.
• Reputation was experimentally manipulated through real-time feedback over multiple rounds.

Main Results:

• The caudate nucleus (dorsal striatum) showed increased activity in response to "bad" reputations (indifferent or unfair partners) compared to "good" reputations (fair partners).
• Individual differences in caudate activity correlated with trusting behavior biases, particularly when facing uncertainty.
• Other brain regions also showed reputation-dependent activation (p < 0.05, whole brain corrected).

Conclusions:

• The caudate plays a crucial role in signaling and integrating reputation information into trust decisions.
• This study provides a neural basis for how experience-based reputation influences social decision-making.