title: Neural substrates underlying the tendency to accept anger-infused ultimatum offers during dynamic social interactions.
abstract: In managing our way through interpersonal conflict, anger might be crucial in determining whether the dispute escalates to aggressive behaviors or resolves cooperatively. The Ultimatum Game (UG) is a social decision-making paradigm that provides a framework for studying interpersonal conflict over division of monetary resources. Unfair monetary UG-offers elicit anger and while accepting them engages regulatory processes, rejecting them is regarded as an aggressive retribution. Ventro-medial prefrontal-cortex (vmPFC) activity has been shown to relate to idiosyncratic tendencies in accepting unfair offers possibly through its role in emotion regulation. Nevertheless, standard UG paradigms lack fundamental aspects of real-life social interactions in which one reacts to other people in a response contingent fashion. To uncover the neural substrates underlying the tendency to accept anger-infused ultimatum offers during dynamic social interactions, we incorporated on-line verbal negotiations with an obnoxious partner in a repeated-UG during fMRI scanning. We hypothesized that vmPFC activity will differentiate between individuals with high or low monetary gains accumulated throughout the game and reflect a divergence in the associated emotional experience. We found that as individuals gained more money, they reported less anger but also more positive feelings and had slower sympathetic response. In addition, high-gain individuals had increased vmPFC activity, but also decreased brainstem activity, which possibly reflected the locus coeruleus. During the more angering unfair offers, these individuals had increased dorsal-posterior Insula (dpI) activity which functionally coupled to the medial-thalamus (mT). Finally, both vmPFC activity and dpI-mT connectivity contributed to increased gain, possibly by modulating the ongoing subjective emotional experience. These ecologically valid findings point towards a neural mechanism that might nurture pro-social interactions by modulating an individual's dynamic emotional experience.
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Weizmann 6, Tel Aviv 64239, Israel; School of Psychological Sciences, Tel-Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel. Electronic address: gadi.gilam@gmail.com.
authors.forename: Gadi
authors.initials: G
authors.lastname: Gilam
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Weizmann 6, Tel Aviv 64239, Israel; School of Psychological Sciences, Tel-Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel.
authors.forename: Tamar
authors.initials: T
authors.lastname: Lin
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Weizmann 6, Tel Aviv 64239, Israel; Faculty of Medicine, Tel-Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel.
authors.forename: Gal
authors.initials: G
authors.lastname: Raz
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Weizmann 6, Tel Aviv 64239, Israel.
authors.forename: Shir
authors.initials: S
authors.lastname: Azrielant
authors.affiliation: Division of Mental Health, Israeli Defense Force Medical Corp, Tel Hashomer, Military Mail 02149, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Fruchter
authors.affiliation: Fuqua School of Business, Duke University, 100 Fuqua Drive, Box 90120, Durham, NC 27708-0120, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Ariely
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Weizmann 6, Tel Aviv 64239, Israel; School of Psychological Sciences, Tel-Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel; Faculty of Medicine, Tel-Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel-Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel. Electronic address: hendlert@gmail.com.
authors.forename: Talma
authors.initials: T
authors.lastname: Hendler
mesh_terms: D000293:Adolescent; D000328:Adult; D000786:Anger / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D003220:Conflict, Psychological; D003657:Decision Making / Q000502:physiology*; D006801:Humans; D007398:Interpersonal Relations; D008125:Locus Coeruleus / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D017397:Prefrontal Cortex / Q000502:physiology*; D012201:Reward; D013788:Thalamus / Q000502:physiology; D055815:Young Adult
keywords: Anger regulation; Interpersonal conflict; Locus coeruleus; Social decision-making; fMRI; vmPFC