Temporal dynamics of implicit moral evaluation: From empathy for pain to mentalizing processes

To understand how we evaluate harm to others, it is crucial to consider the offender's intent and the victim's suffering. Previous research investigating event-related potentials (ERPs) during moral evaluation has been limited by small sample sizes and a priori selection of electrodes and time windows that may bias the results. To overcome these limitations, we examined ERPs in 66 healthy human adults using a data-driven analytic approach involving cluster-based permutation tests. Participants performed an implicit moral evaluation task requiring to observe scenarios depicting intentional harm (IHS), accidental harm (AHS), and neutral actions (NAS) while judging whether each scenario was set indoors or outdoors. Our results revealed two distinct clusters, peaking at ∼170 and ∼250 ms, showing differences between harm scenarios (IHS and AHS) and NAS, suggesting rapid processing of the victim's physical outcome. The difference between IHS and AHS scenarios emerged later, at ∼400 ms, potentially reflecting subsequent evaluation of the agent's intentions. Source analysis showed that brain regions associated with empathy for pain were associated with the earlier peaks at ∼170 and ∼250 ms, while the modulation of the activity of the mentalizing network was presented at ∼250 and ∼400 ms. These findings advance our understanding of the neural mechanisms underlying implicit moral evaluation. Notably, they provide electrocortical new insights for models of implicit moral evaluation, suggesting an early neural response linked to empathy for pain, with subsequent integration of empathy response with mentalizing processes, followed by later cognitive evaluations, likely reflecting the assessment of the agent's moral responsibility.