Neurocognitive correlates and autonomous activity associated to behaviors of rejection and acceptance of unfair offers in the ultimatum game: a systematic review

MOLA, DÉBORA JEANETTE; MICHELINI, YANINA; REYNA, CECILIA; GODOY, JUAN CARLOS

Río de Janeiro

Congreso; 9º IBRO World Congress on Neuroscience; 2015

International Brain Research Organization (IBRO)

The Ultimatum Game (UG) is a traditional task in the study of social decision-making. There is extensive evidence on the behavioral responses in this game. The progress of Neurosciences has enabled to investigate the neurobiological substrates associated with cognitive and emotional processes underlying those answers. The aim of this study was to review the empirical evidence on neurocognitive and autonomous activity associated with rejection and acceptance of unfair offers in the UG. For that purpose, we conducted a search on scientific databases (EBSCO, ScienceDirect and PubMed) using "Ultimatum Game" AND ("Neuroimaging" OR "Neurophysiology" OR "Skin Conductance" OR "Heart Rate") as descriptors. The search covered the period 2000-2015. We included empirical papers that used samples of young and the traditional version of the UG (or comparable versions) Papers that did not employ neurocognitive and/or neurophysiological techniques, comprised clinical samples, or did not measure behavioral response to unfair offers were excluded. In all, 19 papers were analyzed. Specifically, we study the instruments and the results of each paper. As a result, it was observed that 17/19 papers utilized neurocognitive techniques, specifically, Functional Magnetic Resonance Imaging (fMRI), Evoked Potentials (EP) and/or Transcranial Magnetic Stimulation (TMS). Furthermore, 33 papers ALSO employed autonomic measures, this is, Skin Conductance Response (SCR) and Heart Rate (HR). Studies using fMRI show that brain areas frequently activated during rejection of unfair offers were the following: Anterior Insula (AI; 7 papers), Dorsolateral Prefrontal Cortex (DLPFC; 4 papers); Anterior Cingulate Cortex (ACC; 3 papers). An increase in the Ventromedial Prefrontal Cortex (VMPFC) activity and a decrease in the AI activity were associated to acceptance of unfair offers. Neurocognitive studies with EP showed the feedback-related negativity (FRN) was more negative in response to unfair offers. Moreover, the use of TMS showed a less quantity of behaviors of rejection to unfair offers when right DLPFC activity was disrupted. Studies using SCR had observed an increased electrodermal activity during rejection of unfair offers. While other study had found that this behavior produces cardiac deceleration. In conclusion, this review evidences the interaction between cognitive and emotional processes, relation which fluctuates according to acceptance and rejection of unfair offers in the UG.