A Quantitative Neural Biomarker for Rejection Estimation: A Neuroeconomic Approach for Evaluating Theory of Mind

Abstract

The clinical presentation of social phobia suggests that alterations in theory of mind (TOM) may play a systematic role in the development and maintenance of the disorder. In the current study we leverage a quantitative neuroeconmic approach to probe for neural and behavior markers of cognitive TOM, as well as rejection estimation, with a particular focus on social phobia. Participants comprised a non-clinical sample that was divided into low (N = 10) and high (N = 7) social anxiety groups based on self-report. Participants completed a one-sided uncertainty ultimatum game designed to probe individual differences in cognitive TOM, as well as rejection estimation. Contrary to predictions, there were no behavioral differences between high and low social anxiety groups in terms of rejection estimation. Although no between-group differences emerged in the traditional TOM network, significant differences were observed in subregions of the striatum during formulation of offers, likely corresponding to estimation of reward expectations. As hypothesized, and consistent with past research, imaging results support the existence of a network regions implicated in TOM, including the medial prefrontal cortex (MPFC) and the temporal parietal junction (TPJ). In addition to these regions, additional areas, including the caudate and insula, were also active during mentalizing components of the task. Collectively, results suggest a novel role for expected-value computations in the development and maintenance of social phobia.