The neuroscience of empathy - from past to present and future

Cannabidiol Treatment Shows Therapeutic Efficacy in a Rodent Model of Social Transfer of Pain in Pair-Housed Male Mice

Introduction: Prosocial behavior refers to sharing emotions and sensations such as pain. Accumulated data indicate that cannabidiol (CBD), a nonpsychotomimetic component of the Cannabis sativa plant, attenuates hyperalgesia, anxiety, and anhedonic-like behavior. Nevertheless, the role of CBD in the social transfer of pain has never been evaluated. In this study, we investigated the effects of acute systemic administration of CBD in mice that cohabited with a conspecific animal suffering from chronic constriction injury. Furthermore, we assessed whether repeated CBD treatment decreases hypernociception, anxiety-like behavior, and anhedonic-like responses in mice undergoing chronic constriction injury and whether this attenuation would be socially transferred to the partner. Materials and Methods: Male Swiss mice were Housed in pairs for 28 days. On the 14th day of living together, animals were then divided into two groups: cagemate nerve constriction (CNC), in which one animal of each partner was subjected to sciatic nerve constriction; and cagemate sham (CS), subjected to the same surgical procedure but without suffering nerve constriction. In Experiments 1, 2, and 3 on day 28 of living together, the cagemates (CNC and CS) animals received a single systemic injection (intraperitoneally) of vehicle or CBD (0.3, 1, 10, or 30 mg/kg). After 30 min, the cagemates were subjected to the elevated plusmaze followed by exposure to the writhing and sucrose splash tests. For chronic treatment (Exp. 4), sham and chronic constriction injury animals received a repeated systemic injection (subcutaneous) of vehicle or CBD (10 mg/kg) for 14 days after the sciatic nerve constriction procedure. On days 28 and 29 sham and chronic constriction injury animals and their cagemates were behaviorally tested. Results and Conclusion: Acute CBD administration attenuated anxiety-like behavior, pain hypersensitivity, and anhedonic-like behavior in cagemates that cohabited with a pair in chronic pain. In addition, repeated CBD treatment reversed the anxiety-like behavior induced by chronic pain and enhanced the mechanical withdrawal thresholds in Von Frey filaments and the grooming time in the sucrose splash test. Moreover, repeated CBD treatment effects were socially transferred to the chronic constriction injury cagemates.

Emotional processing impairments in patients with insula lesions following stroke

Functional imaging has helped to understand the role of the human insula as a major processing network for integrating input with the current state of the body. However, these studies remain at a correlative level. Studies that have examined insula damage show lesion-specific performance deficits. Case reports have provided anecdotal evidence for deficits following insula damage, but group lesion studies offer a number of advances in providing evidence for functional representation of the insula. We conducted a systematic literature search to review group studies of patients with insula damage after stroke and identified 23 studies that tested emotional processing performance in these patients. Eight of these studies assessed emotional processing of visual (most commonly IAPS), auditory (e.g., prosody), somatosensory (emotional touch) and autonomic function (heart rate variability). Fifteen other studies looked at social processing, including emotional face recognition, gaming tasks and tests of empathy. Overall, there was a bias towards testing only patients with right-hemispheric lesions, making it difficult to consider hemisphere specificity. Although many studies included an overlay of lesion maps to characterise their patients, most did not differentiate lesion statistics between insula subunits and/or applied voxel-based associations between lesion location and impairment. This is probably due to small group sizes, which limit statistical comparisons. We conclude that multicentre analyses of lesion studies with comparable patients and performance tests are needed to definitively test the specific function of parts of the insula in emotional processing and social interaction.

Relationships between the race implicit association test and other measures of implicit and explicit social cognition

Background

The race-based Implicit Association Test (IAT) was proposed to measure individual differences in implicit racial bias subsumed within social cognition. In recent years, researchers have debated the theoretical tenets underpinning the IAT, questioning whether performance on this task: (1) measures implicit attitudes that operate automatically outside of conscious awareness; (2) reflects individual differences in social cognition; and (3) can predict social behavior. One way to better address these research questions is to assess whether the race-IAT correlates with other implicit processes that are subsumed within social cognition.

Aims

The current study assessed whether the race-IAT was related to other commonly used individual difference measures of implicit (and explicit) social cognition. Experiment 1 assessed whether dissociable patterns of performance on the race-IAT were related to measures of implicit imitative tendencies, emotion recognition and perspective taking toward White task actors, as well as explicit measures of trait and state affective empathy and racial bias. Overcoming limitations of task conceptual correspondence, Experiment 2 assessed whether these latter tasks were sensitive in detecting racial biases by using both White and Black task actors and again examined their relationships with the race-IAT.

Method

In two lab-based experiments, 226 and 237 participants completed the race-IAT followed by an extensive battery of social cognition measures.

Results

Across both experiments, pro-White/anti-Black bias on the race-IAT was positively related to a pro-White bias on explicit measures of positive affective empathy. However, relationships between the race-IAT and implicit imitative tendencies, perspective taking, emotion recognition, and explicit trait and negative state affective empathy were statistically equivalent.

Conclusion

The race-IAT was consistently related to explicit measures of positive state affective empathy but not to other individual difference measures of implicit social cognition. These findings are discussed with regards to the theoretical underpinnings of the race-IAT as an individual difference measure of implicit social cognition, as well as alternative explanations relating to the reliability of social cognition measures and the various combinations of general-purpose (social and non-social) executive processes that underpin performance on these tasks.

Effects of emotional valence and intensity on cognitive and affective empathy after insula lesions

The insula plays a central role in empathy. However, the complex structure of cognitive (CE) and affective empathy (AE) deficits following insular damage is not fully understood. In the present study, patients with insular lesions (n = 20) and demographically matched healthy controls (n = 24) viewed ecologically valid videos that varied in terms of valence and emotional intensity. The videos showed a person (target) narrating a personal life event. In CE conditions, subjects continuously rated the affective state of the target, while in AE conditions, they continuously rated their own affect. Mean squared error (MSE) assessed deviations between subject and target ratings. Patients differed from controls only in negative, low-intensity AE, rating their own affective state less negative than the target. This deficit was not related to trait empathy, neuropsychological or clinical parameters, or laterality of lesion. Empathic functions may be widely spared after insular damage in a naturalistic, dynamic setting, potentially due to the intact interpretation of social context by residual networks outside the lesion. The particular role of the insula in AE for negative states may evolve specifically in situations that bear higher uncertainty pointing to a threshold role of the insula in online ratings of AE.

Social Cognition in Adult ADHD: A Systematic Review

The aim of this systematic review was to collect and align the research on social cognition impairments in adults with Attention-deficit/hyperactivity disorder (ADHD). In particular, we selected and analyzed papers on emotion recognition and processing, Theory of Mind (TOM), empathy, and other facets of social cognition as decision making. We identified 16 papers published between 2012 and 2022 which meet inclusion criteria. Papers search, selection, and extraction followed the PRISMA guidelines. In order to summarize data from papers, we used a narrative synthesis approach. Results show different evidence of impairment in social cognition domains in adults with ADHD. Our systematic review suggests the importance of promoting more research on this topic because it is essential to keep in mind that social cognition plays a central role in socialization and social relationships.

Reliability of Greek version of the Toronto empathy questionnaire in medical students and associations with sociodemographic and lifestyle factors

BACKGROUND

Empathy is an important key driver of any therapeutic relationship. It is beneficial for both physicians and patients. Enhancing physician's empathy should be an important goal of medical education. As there was a literature gap regarding the topic of empathy among medical students in Greece, this study aimed to contribute to filling this gap.

METHODS

A cross-sectional study was conducted. A socio-demographic questionnaire and the 52-item Greek version of the Toronto composite empathy scale (TCES) for measuring the cognitive and emotional aspects of empathy in both personal and professional life was administered to all the medical students in the Aristotle University of Thessaloniki, in Greece. Descriptive statistics were displayed for demographics. The associations of the variables were quantified by Chi-2 independence tests and Pearson's Correlation Coefficient. The reliability and validity of the questionnaire was determined by Cronbach's α, Hotelling's T-Squared Test, and Pearson correlation. Paired and Independent Sample T-Tests and One-way ANOVAs indicated statistically significant mean differences among the variables or subgroups of the variables.

RESULTS

The 52-item TCES, 26 for the personal (Per) setting and another 26 for professional (Pro) life, equally divided into cognitive (Cog) and emotional (Emo) empathy in each case. The overall reliability of the TCES questionnaire was found to be high (Cronbach's α = 0.895, significant positive correlations between the subscales). The mean total score of empathy showed that students had a moderately high empathy. Further, there was a statistically significant difference in means between the Per-Cog and Per-Emo settings (p < 0.001), the Pro-Cog and Pro-Emo (p < 0.001), the Per-Cog and Pro-Cog (p = 0.004), and the Per-Emo and Pro-Emo (p < 0.001). Females had significantly higher empathy scores (mean score 208.04) than males (192.5) on the Per-Cog, Per-Emo and Pro-Emo subscales. Furthermore, a positive correlation was found between empathy and factors such as love for animals, interest in medical ethics, belief in God, having an ill person in the family, class year or carrier intention.

CONCLUSIONS

The TCES is applicable to medical students. For the most part our findings were consistent with previous literature. However, we identified some nuances that might draw researchers' attention. The results of this study may contribute to plan interventions in the curriculum to enhance empathy in the medical students.

The Relationship between Empathy and Attachment in Children and Adolescents: Three-Level Meta-Analyses

Empathy is one of the leading social abilities to understand or feel the emotions of other people. Attachment is thought to be a critical influential factor of empathy, as revealed by attachment theory and experimental studies, while empathy is also believed to facilitate the quality of attachment. Although many studies are conducted concerning the two subjects, the direction and magnitude of their relationship still remain unclear. In order to clarify the discrepant results in the previous study and explore the moderators in the empathy-attachment association, three-level meta-analyses were conducted in the present work. Based on 212 effect sizes from 59 samples in 50 studies with a total of 24,572 participants, random effect model analyses showed that empathy was insignificantly correlated with anxious attachment, significantly negatively correlated with avoidant attachment, and significantly positively correlated with secure attachment. The meta-analytic results indicated that children and adolescents with high secure attachment tend to show more empathy than those with low secure attachment. The meta-regression model revealed significant effects of the empathy dimension, culture, empathy measurement tools, and publication state. Additionally, implications and future directions for the empathy-attachment relationship were also discussed.

Neural correlates of compassion - An integrative systematic review

Compassion is a psychological construct that has received increasing attention in recent years. Even though a lot of work has been done to identify neural correlates of empathy across studies, such work has not been properly done on neural correlates of compassion. Therefore, the aim was to systematically review the literature on neural correlates of compassion. We have searched through PsycINFO, PubMed and Web of Science for relevant articles published between 1985 and 2020. We included the studies (n = 35) examining the relationship between brain structure or function and compassion. Screening was performed by two authors, between whom a level of agreement was calculated. The quality of the studies was assessed by measures used in other studies as well by measures specific for our study aims. This study was conducted under PRISMA guidelines. Our analysis revealed that the most frequent neural associations with compassion across all analysed studies can be found in the orbital part of the left inferior frontal gyrus, in the right cerebellum, the bilateral middle temporal gyrus, in the bilateral insula and the right caudate nucleus. Our findings suggest that people displaying a lower compassion tend to have either lower neural activity or a grey matter volume in neural areas associated with reward.

Synchrony with distress in affective empathy and compassion

Sensitivity to suffering of others is a core factor in social cohesion and evolutionary success. The emergence of such sensitivity may occur via two neuro-functional mechanisms. One is sharing the pain and distress of others, which relies on affective empathy. The other involves a caring concern for others' wellbeing, termed compassion. Both affective empathy and compassion are triggered by cues of pain and distress, exhibited by suffering targets. Yet, the mechanisms underlying distress processing in empathy and compassion are not clear. In the current research, we investigated synchrony with a target's distress, as a putative mechanism for continuous processing of distress cues. Participants viewed a video of a target in distress when given two different instructions: they were asked to continuously rate their distress in the affective empathy condition, or their feelings of care in the compassion condition. We used these dynamic ratings as well as participants' autonomic and facial responses to assess multi-channel synchrony with the target's self-rated distress fluctuations. Dynamic ratings and facial corrugator responses were significantly positively synchronized with the target's distress. For the corrugator responses, synchrony with the target was more pronounced than synchrony with participants' own ratings. Autonomic responses exhibited negative synchrony with the target's distress. Synchrony was higher in the affective empathy than in the compassion condition, across channels. These results point to the key role of subjective and physiological synchrony with the target's distress in empathic sharing of negative experiences. They also highlight the attenuation of embodied resonance with distress in compassionate experiences.

Neural correlates of ingroup bias for prosociality in rats

Prosocial behavior, in particular helping others in need, occurs preferentially in response to distress of one’s own group members. In order to explore the neural mechanisms promoting mammalian helping behavior, a discovery-based approach was used here to identify brain-wide activity correlated with helping behavior in rats. Demonstrating social selectivity, rats helped others of their strain (‘ingroup’), but not rats of an unfamiliar strain (‘outgroup’), by releasing them from a restrainer. Analysis of brain-wide neural activity via quantification of the early-immediate gene c-Fos identified a shared network, including frontal and insular cortices, that was active in the helping test irrespective of group membership. In contrast, the striatum was selectively active for ingroup members, and activity in the nucleus accumbens, a central network hub, correlated with helping. In vivo calcium imaging showed accumbens activity when rats approached a trapped ingroup member, and retrograde tracing identified a subpopulation of accumbens-projecting cells that was correlated with helping. These findings demonstrate that motivation and reward networks are associated with helping an ingroup member and provide the first description of neural correlates of ingroup bias in rodents.

Placebo Analgesia Does Not Reduce Empathy for Naturalistic Depictions of Others' Pain in a Somatosensory Specific Way

The shared representations account postulates that sharing another's pain recruits underlying brain functions also engaged during first-hand pain. Critically, direct causal evidence for this was mainly shown for affective pain processing, while the contribution of somatosensory processes to empathy remains controversial. This controversy may be explained, however, by experimental paradigms that did not direct attention towards a specific body part, or that did not employ naturalistic depictions of others' pain. In this preregistered functional magnetic resonance imaging study, we aimed to test whether causal manipulation of first-hand pain affects empathy for naturalistic depictions of pain in a somatosensory-matched manner. Forty-five participants underwent a placebo analgesia induction in their right hand and observed pictures of other people's right and left hands in pain. We found neither behavioral nor neural evidence for somatosensory-specific modulation of pain empathy. However, exploratory analyses revealed a general effect of the placebo on empathy, and higher brain activity in bilateral anterior insula when viewing others' right hands in pain (i.e., corresponding to one's own placebo hand). These results refine our knowledge regarding the neural mechanisms of pain empathy, and imply that the sharing of somatosensory representations seems to play less of a causal role than the one of affective representations.

Cameirão M. Impact of game mode in multi-user serious games for upper limb rehabilitation: a within-person randomized trial on engagement and social involvement

BACKGROUND

Serious games have been increasingly used for motor rehabilitation. However, it is not well known how different game features can be used to impact specific skills properly. Here, we study how the mode (competitive, co-active, collaborative) in which a multi-user game is presented impacts engagement and social involvement.

METHODS

We collected data from 20 pairs of community-dwelling older adults (71.5 ± 8.7 years) in a study following a within-persons design. The participants performed a two-player upper limb rehabilitation game with three conditions (Competitive, Co-active, and Collaborative modes). Engagement and social involvement were assessed through the Core Module and Social Presence Module, respectively, from the Game Experience Questionnaire. To infer the impact of personality and cognitive function, users answered the International Personality Item Pool (short version) and the Montreal Cognitive Assessment, respectively.

RESULTS

Results show that the Collaborative game mode promotes more social involvement when compared to Competitive and Co-active modes. This result is mostly explained by those participants with higher cognitive skills, and those that are more extrovert. Extrovert participants feel more empathy and are behaviorally more involved when playing the Collaborative mode. Also, the Collaborative mode is shown to be appropriate to promote interaction with participants that previously had a distant relationship, while the Competitive mode seems to be more beneficial to promote empathy between players with a closer relationship.

CONCLUSIONS

The Collaborative game mode elicited significantly higher social involvement in terms of Empathy, Positive Affect, and Behavioral Involvement. Hence, this game mode seems to be the most adequate choice to be used in multiplayer rehabilitation settings, where social interaction is intended.

A Relational Framework for Integrating the Study of Empathy in Children and Adults

The development of empathy is central to positive social adjustment. However, issues remain with integrating empathy research conducted with children, adolescents, and adults. The current article (a) provides an overview of how empathy is typically conceptualized and measured in child development and adult research, (b) describes outstanding issues concerning child development and adult research on empathy, and (c) outlines how a relational approach can provide clarity regarding how empathy develops over the course of development. We conclude by offering suggestions for future research on the development of empathy across the lifespan.