Analysis of brain activation. A, The whole-brain main effect contrast Retain > Waive revealed activation in the areas typically associated with intentional/mentalizing processing (e.g., dmPFC, TPJ) and affective salience (e.g., thalamus, dorsal caudate). B, The whole-brain interaction contrast (Partner_Waive > Computer_Waive) > (Partner_Retain > Computer_Retain) revealed activation in the bilateral LOFC and the vmPFC. C, The contrast Computer_Retain > Computer_Waive revealed activation in the bilateral LOFC and the left caudate. D, The contrast Partner_Waive > Partner_Retain revealed activation in the rLOFC and the right vmPFC. E, F, ROI analysis on the activation in the rLOFC (Spitzer et al., 2007) and the vmPFC (Li et al., 2009) based on the previous literature. No activation was found for Partner: Retain > Waive at the current threshold. Detailed statistical results are provided in Table 1. Error bars indicate SE.