title: Reputational priors magnify striatal responses to violations of trust.
abstract: Humans learn to trust each other by evaluating the outcomes of repeated interpersonal interactions. However, available prior information on the reputation of traders may alter the way outcomes affect learning. Our functional magnetic resonance imaging study is the first to allow the direct comparison of interaction-based and prior-based learning. Twenty participants played repeated trust games with anonymous counterparts. We manipulated two experimental conditions: whether or not reputational priors were provided, and whether counterparts were generally trustworthy or untrustworthy. When no prior information is available our results are consistent with previous studies in showing that striatal activation patterns correlate with behaviorally estimated reinforcement learning measures. However, our study additionally shows that this correlation is disrupted when reputational priors on counterparts are provided. Indeed participants continue to rely on priors even when experience sheds doubt on their accuracy. Notably, violations of trust from a cooperative counterpart elicited stronger caudate deactivations when priors were available than when they were not. However, tolerance to such violations appeared to be mediated by prior-enhanced connectivity between the caudate nucleus and ventrolateral prefrontal cortex, which anticorrelated with retaliation rates. Moreover, on top of affecting learning mechanisms, priors also clearly oriented initial decisions to trust, reflected in medial prefrontal cortex activity.
authors: Interdepartmental Centre for Mind/Brain Sciences-CIMeC, University of Trento, 38060 Trento, Italy. elsa.fouragnan@unitn.it
authors: Elsa
authors: E
authors: Fouragnan
authors: Gabriele
authors: G
authors: Chierchia
authors: Susanne
authors: S
authors: Greiner
authors: Remi
authors: R
authors: Neveu
authors: Paolo
authors: P
authors: Avesani
authors: Giorgio
authors: G
authors: Coricelli
mesh_terms: D000328:Adult; D003342:Corpus Striatum / Q000502:physiology*; D006801:Humans; D007398:Interpersonal Relations; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology; D035502:Trust / Q000523:psychology; D055815:Young Adult