Reconsidering longstanding assumptions about the role of medial prefrontal cortex (MPFC) in social evaluation.

The psychological nature of the association between MPFC modulation and social evaluation remains poorly understood. Despite confounds, small samples, and mixed results in existing research, MPFC activation is often interpreted as a reflection of socioemotional association and/or perceived similarity between the self and an evaluation target. The present research addressed issues from the existing literature by examining whether MPFC is modulated by (a) socioemotional associations unconfounded by previous knowledge (memory effects (Study 1, N = 48), repetition suppression (Study 2, N = 43), multi-voxel pattern analysis (Study 1 & 2)) and (b) perceived similarity to self (Study 2). MPFC was modulated by self-reference and trait-relevance, but there was not significant empirical support for the interpretation that MPFC modulation reflects socioemotional association or perceived similarity. These findings highlight the weak basis for prevailing assumptions about the psychological significance of MPFC in social evaluation and the need for studies which test multiple mechanisms.

The functional role of ventral anterior cingulate cortex in social evaluation: disentangling valence from subjectively rewarding opportunities.

Despite robust associations between the ventral anterior cingulate cortex (vACC) and social evaluation, the role of vACC in social evaluation remains poorly understood. Two hypotheses have emerged from existing research: detection of positive valence and detection of opportunities for subjective reward. It has been difficult to understand whether one or both hypotheses are supported because previous research conflated positive valence with subjective reward. Therefore, the current functional magnetic resonance imaging study drew on a social evaluation paradigm that disentangled positive valence and subjective reward. Participants evaluated in-group and out-group politicians in a social evaluation paradigm that crossed trait valence with opportunity for subjectively rewarding affirmation (i.e. a chance to affirm positive traits about in-group politicians and affirm negative traits about out-group politicians). Participants rated in-group politicians more positively and out-group politicians more negatively. One subregion of vACC was modulated by positive valence and another relatively posterior region of vACC was modulated by opportunity for subjective reward (i.e. a politician × valence interaction). The current findings demonstrate the importance of incorporating vACC function into models of social cognition and provide new avenues for sharpening our understanding of the psychological significance of vACC function in social evaluation and related domains such as reward and affect.

Distinct Reward Properties are Encoded via Corticostriatal Interactions.

The striatum serves as a critical brain region for reward processing. Yet, understanding the link between striatum and reward presents a challenge because rewards are composed of multiple properties. Notably, affective properties modulate emotion while informative properties help obtain future rewards. We approached this problem by emphasizing affective and informative reward properties within two independent guessing games. We found that both reward properties evoked activation within the nucleus accumbens, a subregion of the striatum. Striatal responses to informative, but not affective, reward properties predicted subsequent utilization of information for obtaining monetary reward. We hypothesized that activation of the striatum may be necessary but not sufficient to encode distinct reward properties. To investigate this possibility, we examined whether affective and informative reward properties were differentially encoded in corticostriatal interactions. Strikingly, we found that the striatum exhibited dissociable connectivity patterns with the ventrolateral prefrontal cortex, with increasing connectivity for affective reward properties and decreasing connectivity for informative reward properties. Our results demonstrate that affective and informative reward properties are encoded via corticostriatal interactions. These findings highlight how corticostriatal systems contribute to reward processing, potentially advancing models linking striatal activation to behavior.