Experimental procedure.

(A) Timeline for the whole experiment. (B) Timeline for the interpersonal game. In this example, the participant, who was one of the four deciders, made an incorrect estimation, as did one of the other deciders. ISI, inter-stimulus interval.

Behavioral results.

(A) Harm had a stronger effect on guilt than on shame. (B) Responsibility revealed a stronger effect on shame than on guilt. (A, B) We created regression equations for guilt and shame ratings using the coefficient estimates from the linear mixed-effect regression analyses. To illustrate the impacts of harm and responsibility, we visualized the regression lines based on these equations. (C) The coefficient estimates from the linear mixed-effect regression model showed that, compared with shame, guilt exerted a larger effect on compensation. (D) Participants’ average guilt and shame feelings showed no significant difference. (C, D) Data are shown as the mean ± standard error with overlaid dot plots. *P < 0.05, ***P < 0.001; NS, not significant.

Computational modeling results.

(A, B) Model simulations reproduced the behavioral patterns of compensatory decisions as influenced by harm (A) and responsibility (B). Data are shown as the mean ± standard error with overlaid dot plots. (C) The compensatory sensitivity (κ) and compensatory baseline (η) had no significant correlation. The line represents the least squares fit with shading showing the 95% confidence interval.

Neural representation of cognitive antecedents and neural basis of emotion sensitivity.

(A) The quotient of harm divided by the number of wrongdoers (i.e., average harm per person) is represented by the striatum and posterior insula (pINS). (B) The neural responses to average harm per person in the two clusters containing temporoparietal junction (TPJ)/ superior temporal sulcus (STS) and precentral cortex (PRC)/postcentral cortex (POC)/ supplementary motor area (SMA) were negatively correlated with responsibility-driven shame sensitivity. (A, B) Negative T values indicate negative correlation. Whole-brain FWE-cluster correction at P < 0.05 after cluster-forming-threshold at P < 0.001. (C) The TPJ/STS and PRC/POC/SMA clusters showed a significantly stronger negative correlation with shame-driven sensitivity than with guilt-driven sensitivity. Each line represents the least squares fit with shading showing the 95% confidence interval.

Neural basis of compensatory sensitivity.

(A) The dorsomedial prefrontal cortex (DMPFC), supplementary motor area (SMA), and temporal pole (TP) showed significant activity associated with guilt-driven compensatory sensitivity. A red circle marked the region showed significant activity associated with guilt-driven compensatory sensitivity but not with shame-driven compensatory sensitivity. (B) The DMPFC, SMA, right and left inferior parietal lobe (IPL), and left lateral prefrontal cortex (LPFC) showed significant activity associated with shame-driven compensatory sensitivity. Blue circles marked the region showed significant activity associated with shame-driven compensatory sensitivity but not with guilt-driven compensatory sensitivity. (C) The left LPFC showed a significantly stronger positive correlation with shame-driven sensitivity than with guilt-driven sensitivity. Each line represents the least squares fit with shading showing the 95% confidence interval. (A, B, D) The neural correlates of the parameter κ largely overlapped with the regions linked to guilt-driven and shame-driven compensatory sensitivities. The parameter κ is additionally associated with activation in the bilateral anterior insula (aINS). r, right; l, left; Whole-brain FWE-cluster correction at P < 0.05 after cluster-forming-threshold at P < 0.001.

Neural correlates of trait guilt and compensation.

(A) A small-volume correction analysis showed that participants with higher guilt trait scores (i.e., repair action tendencies) have more positive parametric responses to the quotient of harm divided by the number of wrongdoers in the anterior middle cingulate cortex (aMCC). The scatter plot is for presenting the positive correlation relationship between repair action tendencies and neural responses of the aMCC. The line represents the least squares fit with shading showing the 95% confidence interval. (B) The neural finding of the aMCC remained significant after whole-brain correction. Whole-brain FWE-cluster correction at P < 0.05 after cluster-forming-threshold at P < 0.001. (A, B) A circle of dots indicated the position of the aMCC mask. (C) The aMCC parametric responses mediated the relationship between repair action tendencies and compensation. β, path coefficient; CI, 95% confidence interval of β; bold font, significant indirect effect.