Increasing self-other bodily overlap increases sensorimotor resonance to others' pain

Neural empathy mechanisms are shared for physical and social pain, and increase from adolescence to older adulthood

Empathy is a critical component of social interaction that enables individuals to understand and share the emotions of others. We report a preregistered experiment in which 240 participants, including adolescents, young adults, and older adults, viewed images depicting hands and feet in physically or socially painful situations (versus nonpainful). Empathy was measured using imagined pain ratings and EEG mu suppression. Imagined pain was greater for physical versus social pain, with young adults showing particular sensitivity to social pain events compared to adolescents and older adults. Mu desynchronization was greater to pain versus no-pain situations, but the physical/social context did not modulate pain responses. Brain responses to painful situations increased linearly from adolescence to young and older adulthood. These findings highlight shared activity across the core empathy network for both physical and social pain contexts, and an empathic response that develops over the lifespan with accumulating social experience.

Visual perspective and body ownership modulate vicarious pain and touch: A systematic review

We conducted a systematic review investigating the influence of visual perspective and body ownership (BO) on vicarious brain resonance and vicarious sensations during the observation of pain and touch. Indeed, the way in which brain reactivity and the phenomenological experience can be modulated by blurring the bodily boundaries of self-other distinction is still unclear. We screened Scopus and WebOfScience, and identified 31 articles, published from 2000 to 2022. Results show that assuming an egocentric perspective enhances vicarious resonance and vicarious sensations. Studies on synaesthetes suggest that vicarious conscious experiences are associated with an increased tendency to embody fake body parts, even in the absence of congruent multisensory stimulation. Moreover, immersive virtual reality studies show that the type of embodied virtual body can affect high-order sensations such as appropriateness, unpleasantness, and erogeneity, associated with the touched body part and the toucher's social identity. We conclude that perspective plays a key role in the resonance with others' pain and touch, and full-BO over virtual avatars allows investigation of complex aspects of pain and touch perception which would not be possible in reality.

Associations between alcohol consumption and empathy in a non-clinical sample: drinking motives as a moderator

People consume alcohol for multiple reasons. Negative motives are often associated with alcohol-related problems. These problems might be explained by negative effects of high alcohol consumption on empathy. Past studies have associated alcohol use disorder (AUD) with reduced cognitive and affective empathy. Few studies have focused on non-clinical samples and considered behavioral empathy. We examined the links between alcohol consumption and multiple aspects of empathy, and if these links were moderated by negative drinking motives. We collected online data of 520 unselected individuals. All completed the AUD Identification Test (AUDIT) and a Drinking Motives Questionnaire. Affective and cognitive empathy were assessed using the Empathy Quotient. Behavioral empathy was assessed by asking participants how likely they would help the person in each of 24 scenarios involving pain. Helping others in pain was positively predicted by affective and cognitive empathy. Higher AUDIT scores were associated with helping others less, particularly among participants who scored higher on drinking to cope with negative affect. People who drink more and do so to cope with negative affect appear to have less behavioral empathy. This supports the view that negative drinking motives contribute to AUD risk.

I understand your pain but I do not feel it: lower affective empathy in response to others' social pain in narcissism

Introduction

While the relationship between narcissism and empathy has been well-researched, studies have paid less attention to empathic accuracy, i.e., appreciating the precise strength of another person's emotions, and self-other distinction, in terms of the disparity between affective ratings for self and other in response to emotive stimuli. Furthermore, empathic responses may vary depending on whether the pain is physical or social.

Methods

We investigated empathic accuracy, affective empathy, and the distinction between pain, emotion and intensity ratings for self and other, in high (n = 44) and low (n = 43) narcissism groups (HNG and LNG, respectively) selected from 611 students, in response to both types of pain. Participants watched six videos where targets expressed genuine experiences of physical and social pain, and rated the perceived affect and pain experienced by the person in the video and their own empathic emotional responses.

Results and discussion

The HNG displayed lower affective empathy and empathic accuracy than the LNG for both pain types. Within the HNG there was higher empathic accuracy for social vs. physical pain, despite reduced affective empathy for social pain, in contrast to the LNG. In addition to this paradox, the HNG demonstrated greater differences between ratings for the self and for target others than the LNG, suggesting that narcissism is associated with higher self-other distinction in response to viewing other people describing social pain.

The role of external factors in affect-sharing and their neural bases

Affect-sharing, the ability to vicariously feel another person's emotions, is the primary component of empathy that is typically thought to rely on the observer's capacity to feel the emotions of others. However, external signals, such as the target's physical characteristics, have been demonstrated to influence affect-sharing in the neuroscientific literature that speaks to the underappreciated role of external factors in eliciting affect-sharing. We consider factors that influence affect-sharing, including physical cues, emotional cues, situational factors, and observer-target relationships, as well as the neural circuits involved in these processes. Our review reveals that, while neural network activation is primarily responsible for processing affect-sharing, external factors also co-activate a top-down cognitive processing network to modulate the conscious process of affect-sharing. From this knowledge, an integrative framework of external factor interactions with affect-sharing are explained in detail. Finally, we identify critical areas for future research in social and affective neuroscience, including research gaps and incorporation of ecologically valid paradigms.

The pain hidden in your hands: Facial expression of pain reduces the influence of goal-related information in action recognition

The involvement of the sensorimotor system in the perception of painful actions has been repeatedly demonstrated. Yet the cognitive processes corresponding to sensorimotor activations have not been identified. In particular, the respective role of higher-level and lower-level action representations such as goals and grips in the recognition of painful actions is not clear. Previous research has shown that in a neutral context, higher-level action representations (goals) are prioritized over lower-level action representations (grips) and guide action recognition. The present study evaluates to what extent the general priority given to goal-related information in the processing of visual actions can be modulated by a context of pain. We used the action violation paradigm developed by van Elk et al. (2008). In the present action tasks, participants had to judge whether the grip or the goal of object-directed actions displayed in photographs was correct or not. The actress in the photograph could show either a neutral facial expression or a facial expression of pain. In the control task, they had to judge whether the actress expressed pain. In the action tasks, goals influenced grip judgements more than grips influenced goal judgements overall, corroborating the priority given to goal-related information previously reported. Critically, the impact of irrelevant goal-related information on the identification of incorrect grips disappeared in the pain context. Moreover, judgements in the control task were similarly influenced by grip and goal-related information. Results suggest that a context of pain reduces the reliance on higher-level action for action judgments. Findings provide novel directions regarding the cognitive and brain mechanisms involved in action processing in painful situations and support pluralist views of action understanding.

Are women more empathetic than men? Questionnaire and EEG estimations of sex/gender differences in empathic ability

The debate regarding whether women are more empathetic than men has broad scientific, social and clinical implications. However, previous independent questionnaires and brain imaging studies that tested different samples reported inconsistent results regarding sex/gender differences in empathic ability. We conducted three studies to investigate sex/gender differences in empathic ability using large-sample questionnaires and electroencephalography (EEG) measures. We showed that the estimation of empathic ability using the Interpersonal Reactivity Index questionnaire showed higher rating scores in women than in men in all studies. However, our EEG measures of empathy, indexed by both phase-locked and non-phased-locked neural responses to others' painful (vs neutral) facial expressions, support a null hypothesis of the sex/gender difference in empathic ability. In addition, we showed evidence that priming social expectations of women and men's ability to share and care about others' feelings eliminated the sex/gender difference in questionnaire measures of empathic ability. Our large-sample EEG results challenge the notion of women's superiority in empathy that is built based on subjective questionnaire measures that are sensitive to social desirability. Our findings indicate that whether the notion of women's superiority in empathic ability reflects a biological/social difference between women and men or a gender-role stereotype remains an open question.

"I am feeling tension in my whole body": An experimental phenomenological study of empathy for pain

Introduction

Traditionally, empathy has been studied from two main perspectives: the theory-theory approach and the simulation theory approach. These theories claim that social emotions are fundamentally constituted by mind states in the brain. In contrast, classical phenomenology and recent research based on the enactive theories consider empathy as the basic process of contacting others' emotional experiences through direct bodily perception and sensation.

Objective

This study aims to enrich the knowledge of the empathic experience of pain using an experimental phenomenological method.

Materials and methods

Implementing an experimental paradigm used in affective neuroscience, we exposed 28 healthy adults to a video of sportspersons suffering physical accidents while practicing extreme sports. Immediately after watching the video, each participant underwent a phenomenological interview to gather data on embodied, multi-layered dimensions (bodily sensations, emotions, and motivations) and temporal aspects of empathic experience. We also performed quantitative analyses of the phenomenological categories.

Results

Experiential access to the other person's painful experience involves four main themes. Bodily resonance: participants felt a multiplicity of bodily, affective, and kinesthetic sensations in coordination with the sportsperson's bodily actions. Attentional focus: some participants centered their attention more on their own personal discomfort and sensations of rejection, while others on the pain and suffering experienced by the sportspersons. Kinesthetic motivation: some participants experienced the feeling in their bodies to avoid or escape from watching the video, while others experienced the need to help the sportspersons avoid suffering any injury while practicing extreme sports. The temporality of experience: participants witnessed temporal fluctuations in their experiences, bringing intensity changes in their bodily resonance, attentional focus, and kinesthetic motivation. Finally, two experiential structures were found: one structure is self-centered empathic experience, characterized by bodily resonance, attentional focus centered on the participant's own experience of seeing the sportsperson suffering, and self-protective kinesthetic motivation; the other structure is other-centered empathic experience, characterized by bodily resonance, attentional focus centered on the sportsperson, and prosocial kinesthetic motivation to help them.

Discussion

We show how phenomenological data may contribute to comprehending empathy for pain in social neuroscience. In addition, we address the phenomenological aspect of the enactive approach to the three dimensions of an embodiment of human consciousness, especially the intersubjective dimension. Also, based on our results, we suggest an extension of the enactive theory of non-interactive social experience.

Moral transgression modulates empathy for pain: Evidence from ERP and EEG data

Empathy for others' pain plays a critical role in human social interactions; however, the influence of moral transgression remains unclear. We examined the effect of moral transgression on the behavioral and underlying neural processes of empathy for others' pain. Participants performed a pain-empathy task separately in a moral transgression condition and a neutral behavior condition, while an electroencephalogram was recorded. Event-related potential (ERP) results showed that empathic response, as reflected in the late positive component, was smaller when participants performed the task in the moral transgression condition than in the neutral behavior condition. Time-frequency results also showed decreased empathic effect on the beta event-related desynchronization response in the moral transgression as compared to the neutral behavior condition. However, empathic response as reflected in the N2 component was comparable between the moral conditions. These findings demonstrate a moral transgression effect on both cognitive evaluations and sensorimotor processes of empathy for others' pain. Furthermore, spontaneous alpha-oscillation power recorded prior to the onset of empathy-inducing stimuli was significantly higher in the moral transgression condition than in the neutral behavior condition. Consequently, differences in sustained attention may be the physiological foundation of the impact of moral transgression of the observed person on the cognitive and sensorimotor processes of empathy for pain.

Empathic pain observation does not influence automatic imitation in an online setting

Previous research has shown that empathic pain observation can lead to motor facilitation in the form of faster reaction times. However, it is unclear whether participants are focusing on the others' pain or simply focusing on their own discomfort/distress (from watching the videos) during the task. This is an important issue as self- vs other-oriented focusing plays a key role in empathic processing. To address this issue, we combined empathic pain observation with the automatic imitation task (AIT). Previous work has shown that AIT effects are smaller after experiencing pain, which has been interpreted as the result of the experience of pain leading to a self-oriented focus. If empathic pain observation similarly leads to a self-oriented focus, then we should expect similar AIT results after pain observation (smaller AIT effects); however, if it instead leads to an other-oriented focus, then we should see the opposite (larger AIT effects). Although we found initial evidence for the latter hypothesis (Experiment 1), subsequent failed replications suggests that we do not have sufficient evidence to claim that pain observation influences automatic imitation one way or the other (Experiment 2 and 3). We discuss some possible reasons for finding null results in these experiments and suggest future avenues of research to better elucidate this topic.

Mu-desynchronization, N400 and corticospinal excitability during observation of natural and anatomically unnatural finger movements

The action observation networks (AON) (or the mirror neuron system) are the neural underpinnings of visuomotor integration and play an important role in motor control. Besides, one of the main functions of the human mirror neuron system is recognition of observed actions and the prediction of its outcome through the comparison with the internal mental motor representation. Previous studies focused on the human mirror neurons (MNs) activation during object-oriented movements observation, therefore intransitive movements observation effects on MNs activity remains relatively little-studied. Moreover, the dependence of MNs activation on the biomechanical characteristics of observed movement and their biological plausibility remained highly underexplored. In this study we proposed that naturalness of observed intransitive movement can modulate the MNs activity. Event-related desynchronization (ERD) of sensorimotor electroencephalography (EEG) rhythms, N400 event-related potentials (ERPs) component and corticospinal excitability were investigated in twenty healthy volunteers during observation of simple non-transitive finger flexion that might be either biomechanically natural or unnatural when finger wriggled out toward the dorsal side of palm. We showed that both natural and unnatural movements caused mu/beta-desynchronization, which gradually increased during the flexion phase and returned to baseline while observation of extension. Desynchronization of the mu-rhythm was significantly higher during observation of the natural movements. At the same time, beta-rhythm was not found to be sensitive to the action naturalness. Also, observation of unnatural movements caused an increased amplitude of the N400 component registered in the centro-parietal regions. We suggest that the sensitivity of N400 to intransitive action observation with no explicit semantic context might imply the broader role of N400 sources within AON. Surprisingly, no changes in corticospinal excitability were found. This lack of excitability modulation by action observation could be related with dependence of the M1 activity on the observed movement phase.

Mirror, mirror, on the wall: During pandemics, how can self-perception research in people with eating disorders happen at all?

BACKGROUND

'Classic' embodiment illusions (e.g., the feeling of owning another person's hand) involves a three-way interaction between visual, proprioceptive, and tactile stimuli. These illusions have been studied in eating disorder (ED) populations given the potential implications for better understanding and improving body image concerns. Recently, several studies have employed 'tactile-reduced' methods mainly relying on the integration of visual and proprioceptive information to induce embodiment illusions in non-ED populations. To date, there has been no substantial review of these tactile-reduced approaches to consider their potential research and clinical utility in ED populations.

METHOD

This review sought to examine and integrate studies across three areas. Firstly, those that employed tactile-reduced embodiment techniques in non-ED populations. Secondly, those that used classic embodiment techniques to compare whether ED and non-ED populations differ in their susceptibility to embodiment. Thirdly, studies that investigated whether experiencing classic or tactile-reduced embodiment techniques can improve image-related concerns.

RESULTS

For the first aim five studies were identified, all of which found that tactile-reduced methods consistently induced embodiment illusions in non-ED individuals. For the second aim, seven studies comparing ED and non-ED samples were found. ED patients were more susceptible to embodiment than non-ED samples in four studies, less susceptible in one study, and equally susceptible in two studies. Finally, for aim three, amongst the seven studies that used classic or tactile-reduced embodiment methods in ED populations, six reported improvements in self-perception (i.e., reduced body size overestimation, decreased body dissatisfaction and fear of gaining weight).

CONCLUSIONS

Along with the classic approach, tactile-reduced embodiment approaches have implications for ED research and clinical practice, particularly for situations when face-to-face contact with people are restricted. Suggestions are provided for future researchers who wish to ensure best practice for planning embodiment research involving classic and tactile-reduced approaches.

The influence of EEG oscillations, heart rate variability changes, and personality on self-pain and empathy for pain under placebo analgesia

We induced placebo analgesia (PA), a phenomenon explicitly attenuating the self-pain feeling, to assess whether this resulted in reduced empathy pain when witnessing a confederate undergoing such pain experience. We recorded EEG and electrocardiogram during a painful Control and PA treatment in healthy adults who rated their experienced pain and empathy for pain. We derived HRV changes and, using wavelet analysis of non-phase-locked event-related EEG oscillations, EEG spectral power differences for self-pain and other-pain conditions. First-hand PA reduced self-pain and self-unpleasantness, whereas we observed only a slight decrease in other unpleasantness. We derived linear combinations of HRV and EEG band power changes significantly associated with self-pain and empathy for pain changes using PCAs. Lower Behavioral Inhibition System scores predicted self-pain reduction through the mediating effect of a relative HR-slowing and a decreased midline ϑ-band (4-8 Hz) power factor moderated by lower Fight-Flight-Freeze System trait scores. In the other-pain condition, we detected a direct positive influence of Total Empathic Ability on the other-pain decline with a mediating role of the midline β2-band (22-30 Hz) power reduction. These findings suggest that PA modulation of first-hand versus other pain relies on functionally different physiological processes involving different personality traits.

Increasing Self-Other Similarity Modulates Ethnic Bias in Sensorimotor Resonance to Others' Pain

The tendency to simulate the pain of others within our own sensorimotor systems is a vital component of empathy. However, this sensorimotor resonance is modulated by a multitude of social factors including similarity in bodily appearance, e.g. skin colour. The current study investigated whether increasing self-other similarity via virtual transfer to another colour body reduced ingroup bias in sensorimotor resonance. A sample of 58 white participants was momentarily transferred to either a black or a white body using virtual reality technology. We then employed electroencephalography (EEG) to examine event-related desynchronization (ERD) in the sensorimotor beta (13-23 Hz) oscillations while they viewed black, white, and violet photorealistic virtual agents being touched with a noxious or soft object. While the noxious treatment of a violet agent did not increase beta ERD, amplified beta ERD in response to black agent's noxious vs. soft treatment was found in perceivers transferred to black body. Transfer to the white body dismissed the effect. Further exploratory analysis implied that the pain-related beta ERD occurred only when the agent and the participant were of the same colour. The results suggest that even short-lasting changes in bodily resemblance can modulate sensorimotor resonance to others' perceived pain.

The Peripersonal Space in a social world

The PeriPersonal Space (PPS) has been defined as the space surrounding the body, where physical interactions with elements of the environment take place. As our world is social in nature, recent evidence revealed the complex modulation of social factors onto PPS representation. In light of the growing interest in the field, in this review we take a close look at the experimental approaches undertaken to assess the impact of social factors onto PPS representation. Our social world also influences the personal space (PS), a concept stemming from social psychology, defined as the space we keep between us and others to avoid discomfort. Here we analytically compare PPS and PS with the aim of understanding if and how they relate to each other. At the behavioral level, the multiplicity of experimental methodologies, whether well-established or novel, lead to somewhat divergent results and interpretations. Beyond behavior, we review physiological and neural signatures of PPS representation to discuss how interoceptive signals could contribute to PPS representation, as well as how these internal signals could shape the neural responses of PPS representation. In particular, by merging exteroceptive information from the environment and internal signals that come from the body, PPS may promote an integrated representation of the self, as distinct from the environment and the others. We put forward that integrating internal and external signals in the brain for perception of proximal environmental stimuli may also provide us with a better understanding of the processes at play during social interactions. Adopting such an integrative stance may offer novel insights about PPS representation in a social world. Finally, we discuss possible links between PPS research and social cognition, a link that may contribute to the understanding of intentions and feelings of others around us and promote appropriate social interactions.

The effect of somatosensory alpha transcranial alternating current stimulation on pain empathy is trait empathy and gender dependent

Background

Pain empathy enables a person to experience and understand other's pain state by observing others in pain condition. Such prosocial ability is deficient in many psychopathological disorders. Somatosensory alpha suppression is considered as neural correlates of pain empathy and is hypothesized as a target for enhancement of pain empathy. Researches demonstrated that alpha suppression could be enhanced by transcranial alternating current stimulation (tACS) at alpha frequency non‐invasively.

Aims

We applied alpha tACS over the primary somatosensory cortex of healthy subjects to investigate whether alpha tACS is able to enhance the pain empathy performance.

Results

The results showed that there was no difference of pain empathy performance between alpha tACS and sham tACS either when tACS was applied during the task or before task. While in the alpha tACS group, the pain empathy performance was positively correlated with empathic concern of male subjects, the sub‐component of personal trait empathy.

Conclusions

Alpha tACS cannot alter the empathy performance overall, but the modulation effect of alpha tACS on pain empathy is dependent on the gender and trait empathy of subjects.

Investigating the effects of pain observation on approach and withdrawal actions

Previous research has shown that observing another individual receiving a painful stimulus leads to motor facilitation as indexed by faster reaction times. The current study explores whether the type of action that is executed modulates this facilitation effect. Specifically, we examined whether approach-like and withdraw-like movements are differentially influenced by pain observation. In experiment 1, participants performed key presses (approach) and releases (withdraw) after observing another person in pain (vs. no pain). In experiment 2, participants used a joystick to make forward (approach) and backward (withdraw) movements after observing another person in pain (vs. no pain). Across both experiments, we did not find evidence for differential effects of pain observation on approach-like and withdraw-like movements. We do, however, report a robust response-general effect of pain observation on motor behaviour (i.e., faster reaction times after pain observation vs. no pain, regardless of movement type). We discuss these results in relation to the wider emotion, attention, and social neuroscience of empathy literatures.

The Role of Sensorimotor Processes in Pain Empathy

Pain is a salient, aversive sensation which motivates avoidance, but also has a strong social signaling function. Numerous studies have shown that regions of the nervous system active in association with first-hand pain are also active in response to the pain of others. When witnessing somatic pain, such as seeing bodies in painful situations, significant activations occur not only in areas related to the processing of negative emotions, but also in neuronal structures engaged in somatosensation and the control of skeletal muscles. These empathy-related sensorimotor activations are selectively reviewed in this article, with a focus on studies using electrophysiological methods and paradigms investigating responses to somatic pain. Convergent evidence from these studies shows that these activations (1) occur at multiple levels of the nervous system, from the spinal cord up to the cerebral cortex, (2) are best conceptualized as activations of a defensive system, in line with the role of pain to protect body from injury, and (3) contribute to establishing a matching of psychological states between the sufferer and the observer, which ultimately supports empathic understanding and motivate prosocial action. Future research should thus focus on how these sensorimotor responses are related to higher-order empathic responses, including affective sharing and emotion regulation, and how this motivates approach-related prosocial behaviors aimed at alleviating the pain and suffering of others.