Cognitive control: exploring the causal role of the rTPJ in empathy for pain mediated by contextual information

Empathy determines our emotional and social lives. Research has recognized the role of the right temporoparietal junction (rTPJ) in social cognition; however, there is less direct causal evidence for its involvement in empathic responses to pain, which is typically attributed to simulation mechanisms. Given the rTPJ's role in processing false beliefs and contextual information during social scenarios, we hypothesized that empathic responses to another person's pain depend on the rTPJ if participants are given information about people's intentions, engaging mentalizing mechanisms alongside simulative ones. Participants viewed videos of an actress freely showing or suppressing pain caused by an electric shock while receiving 6 Hz repetitive transcranial magnetic stimulation (rTMS) over the rTPJ or sham vertex stimulation. Active rTMS had no significant effect on participants' ratings depending on the pain expression, although participants rated the actress's pain as lower during rTPJ perturbation. In contrast, rTMS accelerated response times for providing ratings during pain suppression. We also found that participants perceived the actress's pain as more intense when they knew she would suppress it rather than show it. These results suggest an involvement of the rTPJ in attributing pain to others and provide new insights into people's behavior in judging others' pain when it is concealed.