Facial expressions are deeply tied to empathy, which plays an important role during social communication. The eye region is effective at conveying facial expressions, especially fear and sadness emotions. Further, it was proved that subliminal stimuli could impact human behavior. This research aimed to explore the effect of subliminal sad, fearful and neutral emotions conveyed by the eye region on a viewer’s empathy for pain using event-related potentials (ERP). The experiment used an emotional priming paradigm of 3 (prime: subliminal neutral, sad, fear eye region information) × 2 (target: painful, nonpainful pictures) within-subject design. Participants were told to judge whether the targets were in pain or not. Results showed that the subliminal sad eye stimulus elicited a larger P2 amplitude than the subliminal fearful eye stimulus when assessing pain. For P3 and late positive component (LPC), the amplitude elicited by the painful pictures was larger than the amplitude elicited by the nonpainful pictures. The behavioral results demonstrated that people reacted to targets depicting pain more slowly after the sad emotion priming. Moreover, the subjective ratings of Personal Distress (PD) (one of the dimensions in Chinese version of Interpersonal Reactivity Index scale) predicted the pain effect in empathic neural responses in the N1 and N2 time window. The current study showed that subliminal eye emotion affected the viewer’s empathy for pain. Compared with the subliminal fearful eye stimulus, the subliminal sad eye stimulus had a greater impact on empathy for pain. The perceptual level of pain was deeper in the late controlled processing stage.

Social pain sharing promotes cooperation, but we still don't know its neural basis. The present study employed functional near-infrared spectroscopy (fNIRS)-based hyperscanning technology to investigate whether interpersonal brain synchronization (IBS) increased between females engaging in cooperative activities after a shared experience of social pain. We utilized the Cyberball paradigm, manipulating social pain by regulating the number of catches for the participants. Dyads in the shared social pain (SP) group received passes only at the beginning of the game, whereas dyads in the control (CT) group had the same number of catches as other players. The results indicate that participants in the SP group showed significant IBS in the right superior frontal cortex (r-SFC, p < 0.05) and left middle frontal cortex (l-MFC, p < 0.05), but no channels in the CT group showed significant IBS (p > 0.05). Further analysis revealed that IBS in r-SFC was significantly higher in the SP group compared to the CT group (p < 0.05). Additionally, IBS in r-SFC was positively correlated with the level of cooperation (r = 0.66, p < 0.001). This study elucidates the neural basis of enhanced cooperation facilitated by shared social pain at the interbrain level. However, it is crucial to acknowledge that this study exclusively enrolled female participants. The generalizability of these findings across genders is yet to be confirmed.

Social pain is a common occurrence in interpersonal interactions, yet limited research has explored the neural mechanisms underlying both social pain and social pain empathy. Existing studies often focus on the neural processes of individuals experiencing pain, referred to as “subjects,” or those empathizing with them, known as “observers.” This study examines the neural mechanisms involved in the process of social pain empathy from the perspective of interpersonal brain synchronization (IBS). To do so, we employed functional near-infrared spectroscopy to simultaneously scan the brains of both subjects and observers in social pain scenarios created using the Cyberball paradigm. The study’s findings indicate that in social pain contexts, the IBS among dyads composed of subjects and observers was significantly enhanced in the dorsolateral prefrontal cortex compared to nonsocial pain contexts. This brain region is associated with emotion regulation. Furthermore, we found that this enhancement depended on the observers’ levels of rejection sensitivity. This study provides the inaugural exploration into the neural mechanisms underlying social pain empathy through the lens of IBS.

Background/Objectives: Empathy for pain enhances our ability to perceive pain and recognize potential dangers. Empathic bias occurs when members of the in-group evoke more intense empathic responses compared to out-group members. In the process of interacting with peers, children develop peer status and spontaneously form peer groups. The present study examined how peer status affects pain empathy in mid-childhood individuals. Methods: A behavior and an event-related potential (ERP) study were conducted. Participants were exposed to pictures of different peers in painful or non-painful situations and completed the pain and unpleasantness rating tasks. Four types of peers were included: popular, rejected, neglected and unfamiliar peers. Results: The behavioral results suggested that the influence of peer status on cognitive empathy is more salient, and the empathic response to unfamiliar peers is higher than neglecting and rejecting peers. The ERP results indicated that larger P3 and LPP amplitude were observed in the painful stimulus condition than in the non-painful stimulus condition. The findings also showed that the popular peers elicited larger LPP amplitude than other peers. The LPP response to unfamiliar peers was larger than to neglected peers. Conclusions: All these results demonstrated that mid-childhood individuals showed empathic bias to in-group members, but it was influenced by peer status in the cognitive processes of pain empathy.