The Yin and Yang of racially (un)biased empathic responses to someone else’s pain

Introduction The ability to emphatically share feelings with those of someone in pain is affected by race difference between the target and the onlooker. A differential empathic activation for race (DEAR effect) in favour of the in-group members has been documented in the brain pain matrix (Azevedo et al., 2012; Xu, Zuo, Wang, & Han, 2009). However, we are also capable of unbiased responses to produce politically correct behaviours towards people of a different race. No brain signature for the politically correct responses has been described yet. Here we propose a neurocognitive model based on the interplay of two contrasting forces at the root of implicitly biased and explicitly unbiased empathic responses. Materials and Methods Twenty-four normal right-handed participants, 12 males (mean age=25.3 years, SD=4.81) were recruited among undergraduate university students. Before the fMRI scans, participants completed a Race (Black & White) Implicit Association Test (IAT) to assess the implicit race biases in favour of Black people or White people (Greenwald et al., 1998). During the fMRI scan participants watched 40 shorts videos in which the actor’s left hand was touched by the experimenter, alternatively with a rubber eraser (harmless stimulus) or with a needle (harmful stimulus), followed by a 4 seconds still image of the hand/tool interaction (stimulus phase); finally a question mark appeared on the centre of the computer screen for 3 seconds (pain assessment phase). At this time, participants judged how painful was the actor’s experience using a Likert scale from 0 (not painful at all) to 3 (highly painful) by pressing an appropriate key on a multi-key response pad. The stimuli involved 20 actors, five for each gender and race (Caucasian & African). A factorial design was computed for all the participants in order to isolate at the single-subject level the brain regions showing a race-by-stimulus interaction effect, our effect of interest that we called “DEAR”: Differential Empathic Activation for Race. In particular, the in-group DEAR effect was computed with the following contrast: [Caucasian (harmful stimulus - harmless stimulus)] - [African (harmful stimulus - harmless stimulus)]. The out-group DEAR effect was obtained by reversing (i.e., by multiplying by -1) the linear contrast for the in-group DEAR effect. These effects were entered in second level random effect analyses. Finally, the regional effects and the performance at the behavioural scales were entered in a bivariate correlation analysis to identify the candidate variables to build up a causal model that may connect behavioural variables and neurofunctional effects by means of a standard path-analysis approach. Results and Discussion Similar brain areas of the pain matrix (as defined by Peyron et al, 2000) were involved at the two time windows for the two complementary DEAR effects, suggesting that the embodied component (the more primitive component) is a necessary feature for the delivery of an empathic response. However, for the out-group DEAR effect recorded during the pain assessment phase there was also a PFC contribution coupled with a revealing behavioural pattern: while the participants judged the Caucasians and Africans’ videos as being equally painful, the expression of such unbiased response had a significant behavioural cost, with higher RTs to assess the pain experienced by the African actors. Taken together, these results suggest that out-group DEAR effect may represent the neurofunctional signature of the top-down controlled process necessary to manifest the typical politically correct response seen under these circumstances (for similar behavioural evidence, see, for example, Azevedo et al., 2012). Our interpretation is further supported by the results of a path analysis. The embodied physiological responses within the pain matrix were moderated by the level of the implicit racist bias as measured by the IAT: the higher the bias, the stronger the DEAR at the time of stimulus presentation for the in-group and the lower the DEAR in favour of the out-group at time of the pain assessment phase. Moreover, these biased physiological responses in the pain matrix predicted the manifestation of the out-group DEAR effect within the DLPFC during the pain assessment phase. We suggest that the out-group DEAR response of the DLPFC may serve to counterbalance the racist implicit bias; this in turn was causally linked with the VLPFC activity, which predicted the latency whereby the behavioural politically correct responses were given. References Azevedo, R. T., Macaluso, E., Avenanti, A., Santangelo, V., Cazzato, V., & Aglioti, S. M. (2012). Their pain is not our pain: Brain and autonomic correlates of empathic resonance with the pain of same and different race individuals. Hum Brain Mapp. doi: 10.1002/hbm.22133 Greenwald, A. G., McGhee, D. E., & Schwartz, J. L. (1998). Measuring individual differences in implicit cognition: the implicit association test. J Pers Soc Psychol, 74(6), 1464-1480. Peyron, R., Laurent, B., & García-Larrea, L. (2000). Functional imaging of brain responses to pain. A review and meta-analysis (2000). Neurophysiol Clin, 30(5), 263-288. Xu, X., Zuo, X., Wang, X., & Han, S. (2009). Do you feel my pain? Racial group membership modulates empathic neural responses. J Neurosci, 29(26), 8525-8529. doi: 10.1523/JNEUROSCI.2418-09.2009