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Attributing outcomes to your own actions or to external causes is essential for appropriately learning which actions lead to reward and which actions do not. Our previous work showed that this type of credit assignment is best explained by a Bayesian reinforcement learning model which posits that beliefs about the causal structure of the environment modulate reward prediction errors (RPEs) during action value updating. In this study, we investigated the brain networks underlying reinforcement learning that are influenced by causal beliefs using functional magnetic resonance imaging while human participants (n = 31; 13 males, 18 females) completed a behavioral task that manipulated beliefs about causal structure. We found evidence that RPEs modulated by causal beliefs are represented in dorsal striatum, while standard (unmodulated) RPEs are represented in ventral striatum. Further analyses revealed that beliefs about causal structure are represented in anterior insula and inferior frontal gyrus. Finally, structural equation modeling revealed effective connectivity from anterior insula to dorsal striatum. Together, these results are consistent with a possible neural architecture in which causal beliefs in anterior insula are integrated with prediction error signals in dorsal striatum to update action values. [ABSTRACT FROM AUTHOR]

Human neuroimaging offers a powerful way to connect animal and human research on emotion, with profound implications for psychological science. However, the gulf between animal and human studies remains a formidable obstacle: human studies typically focus on the cortex and a few subcortical regions such as the amygdala, whereas deeper structures such as the brainstem periaqueductal gray (PAG) play a key role in animal models. Here, we directly assessed the role of PAG in human affect by interleaving in a single fMRI session two conditions known to elicit strong emotional responses—physical pain and negative image viewing. Negative affect and PAG activity increased in both conditions. We next examined eight independent data sets, half featuring pain stimulation and half negative image viewing. In sum, these data sets comprised 198 additional participants. We found increased activity in PAG in all eight studies. Taken together, these findings suggest PAG is a key component of human affective responses. [ABSTRACT FROM AUTHOR]

Abstract: Recent research has begun to identify neural regions associated with self-serving cognition, that is, the tendency to make claims that cast the self in an overly flattering light, yet little is known about the mechanisms supported by neural activation underlying self-serving cognition. One possibility suggested by current research is that MOFC, a region that shows reduced recruitment in relation to self-serving cognition, may support changes in the decision thresholds that influence whether information should be expressed in an evaluation. The current fMRI study addresses this question by combining a signal detection approach and a contextual manipulation that permits the measurement of changes in decision threshold. Participants evaluated their familiarity with blocks of existent and nonexistent information when they believed that self-serving claims of knowledge could either be exposed (accountable condition) or not (unaccountable condition). When held accountable, participants tended to shift their decision thresholds in a conservative (i.e., less self-serving) direction and showed greater activation in orbitofrontal cortex (OFC), medial prefrontal cortex (MPFC) and dorsal anterior cingulate cortex (dACC). Furthermore, the extent to which participants adopted more conservative (i.e., less self-serving) decision thresholds as a function of context (i.e., accountability), the more they recruited MOFC activation. These findings refine current knowledge about the mechanisms performed by neural regions involved in self-serving cognition and suggest a role for MOFC in changing decision thresholds that influence whether information should be expressed in an evaluation. [Copyright &y& Elsevier]