Observer And Object Identity Influences On Empathy For Pain And Their Neural Underpinnings

Background:Empathy refers to the ability to share and understanding others’ feelings without losing sight of the original source of the experience. It is one of most important factors that contribute to moral development, altruism and prosocial behaviors. Amongst many empathic phenomena, understanding and resonating with other people’s pain has drawn most attention of researchers due to its realistic importance. Previous studies have investigated the impact of many factors, such as attention, true/untrue status of painful stimuli, stimulus context (fairness, emotionality), observers’ pain and occupation, and group membership on empathy for pain and its neural substrates. Nevertheless, the observers’ factors that influence empathy for pain have two sources:one from stable individual difference factors such as biological sex, and personality trait; and the other may come from state, temporary psychophysiological changes such as mood fluctuations. However, it has yet to be answered how the above stable and state observer factors may influence empathy for pain, what similarities and discrepancies these factors may have during empathy for pain, and what neural mechanisms they may have underlying these influences.On the other hand, caring for the old and the young is the cultural merits that are highlighted by Chinese traditional culture. Giving more love, care and concerns for the old and the young heavily depends on in-depth understanding of and affective involvement in their difficulties; that is, more empathy for them. Accordingly, we may have greater empathy for the pain of those who need more care such as seniors and children. Nonetheless, currently no study has systematically investigated how the above stable, state observer factors and the factor of the object’s age identity may influence empathy for pain and their neural underpinnings。Goals and methods:Therefore, the present study investigated the influence of object’s age identity, observer’s sex (stable factor), trait anxiety (stable factor) and mood manipulation (state factor) on empathy for pain, and their neural underpinnings. To this end, this dissertation used both Event-Related Potentials (ERPs) and behavioral methods, as well as a pain judgment task(subjects were asked to press one Key for pain stimuli and the other key for no-pain stimuli. response hands were counterbalanced across subjects).Results:In study1, subjects (college students) showed greater empathic responses (namely, greater self unpleasant and other pain reports) for the pain of children compared to olds and adults. This increased empathic concern for children was correlated with the enhanced attractiveness of the children’s faces. This effect was stable, regardless of whether the painful stimuli were delivered statically or dynamically. In study2, the impact of observer’s sex on empathy for other’s pain was mainly manifested by the sex differences in late top-down regulation of self emotional involvement in other’s pain:there was no sex differences in the EPN(early posterior negativity; indexing affective arousal) and early LPP (350-450ms, self regulation); Nevertheless, in the late LPP(450-550ms), females, instead of males, showed greater LPP amplitudes for pain versus no-pain stimuli. LPP amplitudes were positively related to the subjects’ ratings of others’ pain but not to self unpleasantness ratings. Study3showed that the influence of Trait Anxiety (TA) on empathy for pain was characterized by differences in late regulation of emotional involvement:there were significant differences between pain and no-pain conditions in EPN, anterior N200, and LPP in the350-550ms interval. There were no group differences in these components. However, high TA group, instead of low-TA group, showed greater LPP amplitudes for pain versus no-pain stimuli in the550-650ms interval. Similar to Study2, LPPs were positively related to the subjects’ratings of others’pain but not to self unpleasantness. Study4showed that positive mood (happiness) decreased empathic effect for pain in the late LPP stage. There was an early pain effect in the early N110component, and this effect was not influenced by mood manipulation. Nevertheless, LPP (350-550ms) amplitude differences between pain and no-pain stimuli were significantly decreased during positive compared to neutral mood. In contrast, the LPP effect for pain was not significantly different between negative and neutral mood. Conclusions and implications:regardless of stable observer factors like sex, trait anxiety or observer’s state factor like mood fluctuations, the influence of stable/state factors on empathy for pain was just manifested by the influences on late self regulation of emotional involvements. In more detail, females compared to males; high versus low trait anxious group, showed prolonged time and more cognitive resources devoted for top-down regulating of emotional arousal. Positive mood increased the efficacy of self regulation. These results support the late appraisal model of empathy for pain. On the other hand, college students’ greater empathy for children’s pain is probably associated with the humans’ in-born tendencies to care for offsprings during evolution.