Abstract
Cooperation and mutual trust are essential in our society, yet not everybody is trustworthy. In this fMRI study, 62 healthy volunteers performed a repeated trust game, placing trust in a trustworthy or an untrustworthy player. We found that the central amygdala was active during trust behavior planning while the basolateral amygdala was active during outcome evaluation. When planning the trust behavior, central and basolateral amygdala activation was stronger for the untrustworthy player compared to the trustworthy player but only in participants who actually learned to differentiate the trustworthiness of the players. Independent of learning success, nucleus accumbens encoded whether trust was reciprocated. This suggests that learning whom to trust is not related to reward processing in the nucleus accumbens, but rather to engagement of the amygdala. Our study overcomes major empirical gaps between animal models and human neuroimaging and shows how different subnuclei of the amygdala and connected areas orchestrate learning to form different subjective trustworthiness beliefs about others and guide trust choice behavior.
Highlights
Cooperation and mutual trust are essential in our society, yet not everybody is trustworthy
We find that different subnuclei of the amygdala engaged in the trust game show increased activation during different phases of the task paradigm
Our previous study in basolateral amygdala (BLA)-damaged participants highlighted that the BLA is indispensable for learning to differentiate between trustworthy and untrustworthy players in the trust game[2]
Summary
Cooperation and mutual trust are essential in our society, yet not everybody is trustworthy. The amygdala is widely regarded as paramount for social cognition[4], but it has been investigated as a uniform structure in the majority of human neuroimaging studies[5] While this approach may be due to the limited spatial specificity of functional MRI in the ventral brain[6,7], it ignores the structural and functional heterogeneity of this brain area and its subnuclei[8]. Our recent research in participants with BLA lesions[2] proposed that a network centered around the BLA adaptively subserves learning to trust and to distrust others This novel insight was based on a trust game task in which the participants repeatedly interacted with a trustworthy and an untrustworthy interaction partner. MRI in a healthy neurotypical population we employ the exact same behavioral paradigm to confirm and extend these findings to the specific functions of the separate subnuclei of the amygdala and the networks they are a part of
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
