Empathy constrained: Prejudice predicts reduced mental simulation of actions during observation of outgroups

On social neuroscience methodologies and their applicability to group processes and intergroup relations

Group processes and intergroup relations are one of the most important topics examined by social psychologists. Recent advancements in social neuroscience methodologies provide valuable insight into these processes by allowing researchers to examine different psychological phenomena via neural processes that instantiate them while individuals interact with ingroup and outgroup members. This includes responses that occur outside conscious awareness or are deemed undesirable to overtly express. The purpose of this review is to provide an overview of the different social neuroscience methodologies that afford these possibilities. Specifically, functional magnetic resonance imaging (fMRI), electroencephalography (EEG), functional near infrared spectroscopy (fNIRS), transcranial magnetic stimulation (TMS), and genetic approaches will be discussed. Each section includes a discussion of what the methodology is and how it is used to assess neural function. A secondary goal of the review is to highlight recent studies that have utilized the aforementioned tools to better understand intergroup processes and interactions. Throughout, advantages and limitations of each approach are discussed, particularly with respect to the study of group processes and intergroup relations.

The influence of group membership and individual differences in psychopathy and perspective taking on neural responses when punishing and rewarding others

Understanding how neural processes involved in punishing and rewarding others are altered by group membership and personality traits is critical in order to gain a better understanding of how socially important phenomena such as racial and group biases develop. Participants in an fMRI study (n = 48) gave rewards (money) or punishments (electroshocks) to in-group or out-group members. The results show that when participants rewarded others, greater activation was found in regions typically associated with receiving rewards such as the striatum and medial orbitofrontal cortex, bilaterally. Activation in those regions increased when participants rewarded in-group compared to out-group members. Punishment led to increased activation in regions typically associated with Theory of Mind including the medial prefrontal cortex and posterior superior temporal sulcus, as well as regions typically associated with perceiving others in pain such as the dorsal anterior cingulate cortex, anterior insula and lateral orbitofrontal cortex. Interestingly, in contrast to the findings regarding reward, activity in these regions was not moderated by whether the target of the punishment was an in- or out-group member. Additional regression analysis revealed that participants who have low perspective taking skills and higher levels of psychopathy showed less activation in the brain regions identified when punishing others, especially when they were out-group members. In sum, when an individual is personally responsible for delivering rewards and punishments to others, in-group bias is stronger for reward allocation than punishments, marking the first neuroscientific evidence of this dissociation.

Group membership affects spontaneous mental representation: failure to represent the out-group in a joint action task

Predicting others' actions is crucial to successful social interaction. Previous research on joint action, based on a reaction-time paradigm called the Joint Simon Task, suggests that successful joint action stems from the simultaneous representation of the self with the other. Performance on this task provides a read-out of the degree of intrusion from a partner that participants experience from acting jointly compared to acting alone, which in turn is a measure of the degree to which participants mentally represent their co-actors during the task. To investigate the role of perceived group membership in this type of joint action and its influence on the representation of others, we first subjected participants to a minimal group paradigm while manipulating differences in social competition. We then asked participants to do the Joint Simon Task in pairs with an in-group or out-group member. Only participants who acted with an "in-group" partner on the joint task showed altered reaction times compared to when acting alone, presumably a change caused by the simultaneous and automatic representation of their in-group partner. In contrast, participants who acted with an out-group partner were unaffected in their reactions when doing the joint task, showing no evidence of representation of their out-group partner. This effect was present in both the high-competition and low-competition conditions, indicating that the differential effects of group membership on representation during joint action were driven by perceived group membership and independent of the effects of social competition. We concluded that participants failed to represent out-group members as socially relevant agents not based on any personality or situational characteristics, but in reaction only to their status as "other". In this way group membership appears to affect cognition on a very immediate and subconscious level.

Perception of race-related features modulates neural activity associated with action observation and imitation

The present study examines whether race-specific features affect biological motion perception. Activation of the neural action observation and imitation network was measured using functional MRI. During scanning, individuals were asked to imitate and observe basic hand movements of own-race and other-race actors. Results indicate that three key areas often associated with action observation and imitation, the inferior parietal lobule, superior parietal lobule, and superior temporal sulcus, were more active when participants imitated and observed hand movements of own-race relative to other-race actors. These findings indicate that several regions associated with the neural imitation/observation network are sensitive to race-related features.

Modulations of mirroring activity by desire for social connection and relevance of movement

Mirroring neurons fire both when an individual moves and observes another move in kind. This simulation of others' movements is thought to effortlessly and ubiquitously support empathetic connection and social understanding. However, at times this could be maladaptive. How could a boxer mirror a losing opponent's expressions of fatigue, feeling his weariness, precisely when strength is required? Clearly, the boxer must emotionally disconnect from his opponent and those expressions of fatigue must become irrelevant and not mirrored. But, movements that inform of his opponent's intentions to deliver an incoming blow are quite relevant and still should require mirroring. We tested these dimensions of emotional connectedness and relevance of movement in an electroencephalography experiment, where participants' desires to socially connect with a confederate were manipulated. Before manipulation, all participants mirrored the confederate's purely kinematic (a hand opening and closing) and goal-directed (a hand opening and closing around a token that the participant desired) hand movements. After manipulation, unfairly treated subjects ceased to mirror the purely kinematic movements but continued to mirror goal-relevant movements. Those treated fairly continued to mirror all movements. The results suggest that social mirroring can be adaptive in order to meet the demands of a varied social environment.

Testing the “Black Code”

The present experiment examined identity denial and reduced empathy for in-group (vs. out-group) targets as a function of the racial composition of their social networks. Black participants rated in-group (Black) targets as more weakly racially identified and expressed less empathy for in-group targets with cross-race close friends versus same-race close friends or no friends. Furthermore, the effect of social network composition on empathy was mediated by perceived racial identity. These findings were limited to the in-group target. Although the out-group (White) target was rated as more weakly identified when shown with cross-race close friends versus same-race close friends or no friends, neither social network composition nor perceived racial identity predicted empathy for the out-group target. These findings extend previous research on identity denial and suggest that, for Blacks, closely associating with Whites undermines the usually robust pattern of in-group empathy.

The neuroscience of in-group bias

Racism and in-group favoritism is prevalent in our society and has been studied in Social Psychology for a long time. Recently it has become possible to investigate the neural mechanisms that underlie these in-group biases, and hence this review will give an overview of recent developments on the topic. Rather than relying on a single brain region or network, it seems that subtle changes in neural activation across the brain, depending on the modalities involved, underlie how we divide the world into 'us' versus 'them'. These insights have important implications for our understanding of how in-group biases develop and could potentially lead to new insights on how to reduce them.

Experiencing ownership over a dark-skinned body reduces implicit racial bias

Previous studies have investigated how existing social attitudes towards other races affect the way we 'share' their bodily experiences, for example in empathy for pain, and sensorimotor mapping. Here, we ask whether it is possible to alter implicit racial attitudes by experimentally increasing self-other bodily overlap. Employing a bodily illusion known as the 'Rubber Hand Illusion', we delivered multisensory stimulation to light-skinned Caucasian participants to induce the feeling that a dark-skinned hand belonged to them. We then measured whether this could change their implicit racial biases against people with dark skin. Across two experiments, the more intense the participants' illusion of ownership over the dark-skinned rubber hand, the more positive their implicit racial attitudes became. Importantly, it was not the pattern of multisensory stimulation per se, but rather, it was the change in the subjective experience of body ownership that altered implicit attitudes. These findings suggest that inducing an overlap between the bodies of self and other through illusory ownership is an effective way to change and reduce negative implicit attitudes towards outgroups.

Cognitive empathy and motor activity during observed actions

Whether empathy depends on activation of the mirror neuron system is controversial. This study tested the relationship between cognitive empathy and motor activation during action observation through the sensorimotor system. EEG activity was recorded over the motor area while participants observed and then performed a task demonstrated by a model. Analyses revealed significant suppression in mu/alpha (8-12Hz) and beta (18-22Hz) EEG bands, indicative of sensorimotor activity, during both observed and executed actions. Crucially, participants rating higher in perspective taking as a measure of trait cognitive empathy showed significantly less beta suppression when observing actions. The direction of this relationship, contrary to studies involving induced emotional empathy, may reflect individual differences in mentalizing and mirroring mechanisms to understand others' actions. Implications of these findings for the hypothesised empathy-mirror neuron system link are discussed.

Beyond the colour of my skin: how skin colour affects the sense of body-ownership

Multisensory stimulation has been shown to alter the sense of body-ownership. Given that perceived similarity between one's own body and those of others is crucial for social cognition, we investigated whether multisensory stimulation can lead participants to experience ownership over a hand of different skin colour. Results from two studies using introspective, behavioural and physiological methods show that, following synchronous visuotactile (VT) stimulation, participants can experience body-ownership over hands that seem to belong to a different racial group. Interestingly, a baseline measure of implicit racial bias did not predict whether participants would experience the RHI, but the overall strength of experienced body-ownership seemed to predict the participants' post-illusion implicit racial bias with those who experienced a stronger RHI showing a lower bias. These findings suggest that multisensory experiences can override strict ingroup/outgroup distinctions based on skin colour and point to a key role for sensory processing in social cognition.

Intergroup differences in the sharing of emotive states: neural evidence of an empathy gap

Empathy facilitates prosocial behavior and social understanding. Here, however, we suggest that the most basic mechanism of empathy--the intuitive sharing of other's emotional and motivational states--is limited to those we like. Measuring electroencephalographic (EEG) alpha oscillations as people observed ingroup vs outgroup members, we found that participants showed similar activation patterns when feeling sad as when they observed ingroup members feeling sad. In contrast, participants did not show these same activation patterns when observing outgroup members and even less so the more they were prejudiced. These findings provide evidence from brain activity for an ingroup bias in empathy: empathy may be restricted to close others and, without active effort, may not extend to outgroups, potentially making them likely targets for prejudice and discrimination.

Right frontal cortical asymmetry predicts empathic reactions: support for a link between withdrawal motivation and empathy

Depression, diminished positive affect, and exaggerated negative affect have all been linked to right frontal cortical asymmetry as measured by electroencephalography (EEG). Emerging evidence, however, suggests that right frontal EEG asymmetry might be linked to empathic responding. EEG was used to assess baseline asymmetries in frontal brain activity. Participants viewed images associated with a charity and then rated their sadness, personal distress, perspective-taking, and empathic concern towards the images. We found that baseline measures of right frontal asymmetry were a significant predictor of empathic concern, a relationship that was mediated by feelings of sadness. These results provide a more complex view of right frontal asymmetry and suggest that this pattern of brain activity might facilitate sensitivity towards the suffering of others.

Seeing is believing: neural mechanisms of action-perception are biased by team membership

Group identification can lead to a biased view of the world in favor of "in-group" members. Studying the brain processes that underlie such in-group biases is important for a wider understanding of the potential influence of social factors on basic perceptual processes. In this study, we used functional magnetic resonance imaging (fMRI) to investigate how people perceive the actions of in-group and out-group members, and how their biased view in favor of own team members manifests itself in the brain. We divided participants into two teams and had them judge the relative speeds of hand actions performed by an in-group and an out-group member in a competitive situation. Participants judged hand actions performed by in-group members as being faster than those of out-group members, even when the two actions were performed at physically identical speeds. In an additional fMRI experiment, we showed that, contrary to common belief, such skewed impressions arise from a subtle bias in perception and associated brain activity rather than decision-making processes, and that this bias develops rapidly and involuntarily as a consequence of group affiliation. Our findings suggest that the neural mechanisms that underlie human perception are shaped by social context.

Racial identification modulates default network activity for same and other races

Racial identification shapes self-concept and how people share in and respond to the emotional states of others around them. Prior neuroimaging studies have demonstrated the role of the neural default network in self-referential and empathic processing. However, how racial identification affects neural processing of social information remains unknown. Here, we examined the effect of racial identification on neural response related to social perception among African American and Caucasian American individuals using functional magnetic resonance imaging. Our results demonstrate that degree of racial identification predicts activity within cortical midline structures of the default network in response to viewing racial ingroup, relative to outgroup members, and activity within the medial temporal lobe subsystem of the default network in response to viewing racial outgroup, relative to ingroup members. Broadly, our findings suggest that the strength of racial identification is associated with differential recruitment of neural and cognitive processes to understand and respond to other people within and outside of one's racial group.

Towards a Cultural Neuroscience of Empathy and Prosociality

Recent evidence from the social neuroscience of empathy suggests that there is core neural circuitry underlying empathy in humans, and important roles for top—down and bottom—up processes in the production and regulation of empathic experience. Less well understood is how cultural and genetic forces give rise to empathy and prosocial behavior within and across groups. Here I argue that culture-gene coevolutionary theory may play an important role in understanding how and when empathy is experienced, and that future research in cultural neuroscience is needed to understand how cultural and genetic factors shape empathic neural response.