Viewing pain and happy faces elicited similar changes in postural body sway

Empathy bodyssence: temporal dynamics of sensorimotor and physiological responses and the subjective experience in synchrony with the other's suffering

Background

Empathy is foundational in our intersubjective interactions, connecting with others across bodily, emotional, and cognitive dimensions. Previous evidence suggests that observing individuals in painful situations elicits whole bodily responses, unveiling the interdependence of the body and empathy. Although the role of the body has been extensively described, the temporal structure of bodily responses and its association with the comprehension of subjective experiences remain unclear.

Objective

Building upon the enactive approach, our study introduces and examines "bodyssence," a neologism formed from "body" and "essence." Our primary goal is to analyze the temporal dynamics, physiological, and phenomenological elements in synchrony with the experiences of sportspersons suffering physical accidents.

Methods

Using the empirical 5E approach, a refinement of Varela's neurophenomenological program, we integrated both objective third-person measurements (postural sway, electrodermal response, and heart rate) and first-person descriptions (phenomenological data). Thirty-five participants watched videos of sportspersons experiencing physical accidents during extreme sports practice, as well as neutral videos, while standing on a force platform and wearing electrodermal and heart electrodes. Subsequently, micro-phenomenological interviews were conducted.

Results

Bodyssence is composed of three distinct temporal dynamics. Forefeel marks the commencement phase, encapsulating the body's pre-reflective consciousness as participants anticipate impending physical accidents involving extreme sportspersons, manifested through minimal postural movement and high heart rate. Fullfeel, capturing the zenith of empathetic engagement, is defined by profound negative emotions, and significant bodily and kinesthetic sensations, with this stage notably featuring an increase in postural movement alongside a reduction in heart rate. In the Reliefeel phase, participants report a decrease in emotional intensity, feeling a sense of relief, as their postural control starts to reach a state of equilibrium, and heart rate remaining low. Throughout these phases, the level of electrodermal activity consistently remains high.

Conclusion

This study through an enactive approach elucidates the temporal attunement of bodily experience to the pain experienced by others. The integration of both first and third-person perspectives through an empirical 5E approach reveals the intricate nature of bodyssence, offering an innovative approach to understanding the dynamic nature of empathy.

Keeping distance or getting closer: How others' emotions shape approach-avoidance postural behaviors and preferred interpersonal distance

Understanding the influence of emotions on social interactions is important for a global understanding of the dynamics of human behavior. In this study, we investigated the interplay between emotions, spontaneous approach or avoidance tendencies, and the regulation of interpersonal distance. Fifty-seven healthy adults participated in a three-part experiment involving exposure to approaching or withdrawing emotional faces (neutral, happy, sad, fearful, disgusted, angry). The sequence began with an initial computerized stop-distance task, followed by a postural task in which participants' approach or avoidance tendencies were quantified via center of pressure (CoP-Y) displacements on a force platform, and concluded with a final computerized stop-distance task. Our findings revealed a gradient in postural responses, with the most forward CoP-Y displacements for neutral and happy faces, indicative of approach tendencies. These were followed by lesser forward displacements for sad and fearful faces, and most pronounced backward displacements for disgusted and angry faces, indicating avoidance. Furthermore, we observed modulations in participants' preferred interpersonal distance based on emotional cues, with neutral and happy faces associated with shorter distances, and disgusted and angry faces linked to larger distances. Despite these similar results, no direct correlation was found between CoP-Y and preferred interpersonal distance, underscoring a dissociation between spontaneous and voluntary social behaviors. These results contribute to a better understanding of how emotional expressions shape social interactions and underscore the importance of considering emotional cues, postural action tendencies, and interpersonal distance in facilitating successful social interactions.

Postural control in emotional states: An effect of biofeedback

BACKGROUND

Emotional states in the short term and affective impairments, such as anxiety and depression in the long run, can have a significant impact on postural control. Individuals with these conditions often struggle with maintaining balance during emotionally charged situations, which can increase their risk of falls and injuries. Biofeedback has been proposed as a potential intervention to improve postural control during emotional induction.

RESEARCH QUESTION

How do emotional stimuli affect postural control performance in the presence of real-time postural feedback?

METHODS

Forty-two participants took part in the study. The visual stimuli used in the experiment to induce emotions of various valence in the subjects were video clips, containing a series of pictures (24 positive, 24 neutral and 24 negative pictures). During the experiment, participants were required to maintain balance standing on a force platform while watching the videos on a computer screen. For each subject, three sessions of 480 s were generated, each of which included two conditions: with and without biofeedback (a target on the screen indicating the subject's position relative to the center of pressure (CoP).

RESULTS

The No Feedback condition provoked a higher medial-lateral and anterior-posterior sway, but lower velocity of CoP than the Feedback condition. We did not find any effect of the valence of emotional videos on indicators of postural control in No Feedback condition. However, both negative and positive videos provoked a lower velocity of CoP in comparison to neutral videos in the Feedback condition.

SIGNIFICANCE

Changes observed in postural control during the Feedback condition in the presence of emotional stimuli (both negative and positive) could be explained by the shift in attention from the task of maintaining posture to the emotional videos. The results of this study have important implications for clinicians involved in postural training and rehabilitation.

Moving beyond the lab: investigating empathy through the Empirical 5E approach

Empathy is a complex and multifaceted phenomenon that plays a crucial role in human social interactions. Recent developments in social neuroscience have provided valuable insights into the neural underpinnings and bodily mechanisms underlying empathy. This methodology often prioritizes precision, replicability, internal validity, and confound control. However, fully understanding the complexity of empathy seems unattainable by solely relying on artificial and controlled laboratory settings, while overlooking a comprehensive view of empathy through an ecological experimental approach. In this article, we propose articulating an integrative theoretical and methodological framework based on the 5E approach (the "E"s stand for embodied, embedded, enacted, emotional, and extended perspectives of empathy), highlighting the relevance of studying empathy as an active interaction between embodied agents, embedded in a shared real-world environment. In addition, we illustrate how a novel multimodal approach including mobile brain and body imaging (MoBi) combined with phenomenological methods, and the implementation of interactive paradigms in a natural context, are adequate procedures to study empathy from the 5E approach. In doing so, we present the Empirical 5E approach (E5E) as an integrative scientific framework to bridge brain/body and phenomenological attributes in an interbody interactive setting. Progressing toward an E5E approach can be crucial to understanding empathy in accordance with the complexity of how it is experienced in the real world.

"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.

Differences in Postural Balance, Pain Sensitivity and Depression between Individuals with Acute and Chronic Back Pain

To compare differences in postural balance, pain and depression in patients with chronic and acute low back pain, twenty patients with chronic and twenty patients with acute low back pain from the Edward Francis Small Hospital (Banjul, Gambia), as well as 20 age-matched healthy controls participated in the study. A modified Romberg test was used to assess postural balance during one minute with closed eyes. Body sway in the anteroposterior and mediolateral axes was video-recorded during test performance and further analyzed with an open source software for movement analyses (CvMob). Pain sensitivity was assessed by means of pressure pain thresholds and depression by a self-report questionnaire (PHQ-9). As results, patients with chronic low back pain displayed higher body sway in the anteroposterior and mediolateral axes, as well as faster body sway than patients with acute low back pain and healthy controls. Nevertheless, group differences disappeared when depression was introduced as a covariate, indicating a major role of depression in postural balance deficits of patients with pain disorders. As conclusions, the assessment of postural balance and depression should be implemented in the clinical routine for the design of tailored interventions in pain conditions.

Are You “Gazing” at Me? How Others' Gaze Direction and Facial Expression Influence Gaze Perception and Postural Control

In everyday life, interactions between humans are generally modulated by the value attributed to the situation, which partly relies on the partner's behavior. A pleasant or cooperating partner may trigger an approach behavior in the observer, while an unpleasant or threatening partner may trigger an avoidance behavior. In this context, the correct interpretation of other's intentions is crucial to achieve satisfying social interactions. Social cues such as gaze direction and facial expression are both fundamental and interrelated. Typically, whenever gaze direction and facial expression of others communicate the same intention, it enhances both the interlocutor's gaze direction and the perception of facial expressions (i.e., shared signal hypothesis). For instance, an angry face with a direct gaze is perceived as more intense since it represents a threat to the observer. In this study, we propose to examine how the combination of others' gaze direction (direct or deviated) and emotional facial expressions (i.e., happiness, fear, anger, sadness, disgust, and neutrality) influence the observer's gaze perception and postural control. Gaze perception was indexed by the cone of direct gaze (CoDG) referring to the width over which an observer feels someone's gaze is directed at them. A wider CoDG indicates that the observer perceived the face as looking at them over a wider range of gaze directions. Conversely, a narrower CoDG indicates a decrease in the range of gaze directions perceived as direct. Postural control was examined through the center of pressure displacements reflecting postural stability and approach-avoidance tendencies. We also investigated how both gaze perception and postural control may vary according to participants' personality traits and emotional states (e.g., openness, anxiety, etc.). Our results confirmed that gaze perception is influenced by emotional faces: a wider CoDGs was observed with angry and disgusted faces while a narrower CoDG was observed for fearful faces. Furthermore, facial expressions combined with gaze direction influence participants' postural stability but not approach-avoidance behaviors. Results are discussed in the light of the approach-avoidance model, by considering how some personality traits modulate the relation between emotion and posture.

An Observational Study Comparing Fibromyalgia and Chronic Low Back Pain in Somatosensory Sensitivity, Motor Function and Balance

Fibromyalgia (FM) and chronic low back pain (CLBP) have shared pathophysiology and have a considerable impact on patients' daily activities and quality of life. The main objective of this study was to compare pain impact, somatosensory sensitivity, motor functionality, and balance among 60 patients with FM, 60 patients with CLBP, and 60 pain-free controls aged between 30 and 65 years. It is essential to know the possible differences existing in symptomatology of two of the major chronic pain processes that most affect the population, such as FM and CLBP. The fact of establishing possible differences in sensory thresholds, motor function, and proprioceptive measures among patients with FM and CLBP could bring us closer to a greater knowledge of the chronic pain process. Through an observational study, a comparison was made between the three groups (FM, CLBP, and pain-free controls) evaluating functional performance, postural balance, kinematic gait parameters, strength, depression, fatigue, and sensitivity to pain and vibration. Patients with chronic pain showed worse somatosensory sensitivity (p < 0.001) and motor function (p < 0.001) than pain-free controls. Moreover, patients with FM showed greater pain impact (p < 0.001) and bigger somatosensory (p < 0.001) and motor deficiencies (p < 0.001) than patients with CLBP. Further research should explore the possible reasons for the greater deterioration in patients with FM in comparison with other chronic pain conditions. Our results, showing the multiple areas susceptible of deterioration, make it necessary to adopt interdisciplinary interventions focused both on physical and emotional dysfunction.

Head movement differs for positive and negative emotions in video recordings of sitting individuals

Individuals tend to approach positive stimuli and avoid negative stimuli. Furthermore, emotions influence whether individuals freeze or move more. These two kinds of motivated behavior refer to the approach/avoidance behavior and behavioral freezing/activation. Previous studies examined (e.g., using forced platforms) whether individuals' behavior depends on stimulus' valence; however, the results were mixed. Thus, we aimed to test whether emotions' effects on spontaneous whole-body behavior of standing individuals also occur in the seated position. We used a computer vision method to measure the head sway in video recordings that offers ease of use, replicability, and unobtrusiveness for the seated research participant. We analyzed behavior recorded in the laboratory during emotion manipulations across five studies totaling 932 participants. We observed that individuals leaned more forward and moved more when watching positive stimuli than when watching negative stimuli. However, individuals did not behave differently when watching positive or negative stimuli than in the neutral condition. Our results indicate that head movements extracted from seated individuals' video recordings can be useful in detecting robust differences in emotional behavior (positive vs. negative emotions).

Emotional Influences on Cognitive Processing in Fibromyalgia Patients With Different Depression Levels: An Event-related Potential Study

OBJECTIVES

Comorbid symptoms in fibromyalgia (FM) syndrome, such as mood disorders and cognitive dysfunction, may lead to greater functional impairment than pain itself. This study aimed to unravel the modulating role of depression in response execution and inhibition in FM using an emotional go/no-go task.

MATERIALS AND METHODS

In total, 17 FM patients with low depression, 18 FM patients with high depression, and 18 pain-free controls were included. Pain, happy, and neutral faces were pseudorandomly presented, and participants were asked to respond to male faces (go trials) by pressing a button, and to inhibit their responses if female faces were presented (no-go trials).

RESULTS

FM patients with high depression showed lower positive affect scores, higher negative affect and pain vigilance scores, and slower reaction times, than FM patients with low depression and pain-free controls. Both subgroups of FM patients also rated pain faces as more arousing than pain-free controls. The lack of group differences in our electrophysiological data, neither in N200 nor in P300 amplitudes, seems to indicate that there was no significant impairment in response execution in response inhibition due to pain.

DISCUSSION

Taken together, these results add evidence to the notion that depression is associated with higher affective dysregulation and deficit of information-processing speed in FM. Furthermore, our data suggest that pain induces a bias to pain-related information, but the absence of significant group differences in event-related potential amplitudes, calculated with analyses of covariance (ANCOVA) (with pain intensity), seem to show that pain intensity is not a predictor for cognitive dysfunctions.

Influence of affective auditory stimuli on balance control during static stance

The main purpose of this study was to examine the effects of affective auditory stimuli on balance control during static stance. Twelve female and 12 male participants were recruited. Each participant completed four upright standing trials including three auditory stimuli trials and one baseline trial (ie no auditory stimuli). The three auditory stimuli trials corresponded to the pleasant, neutral and unpleasant sound conditions. Center of pressure (COP) measures were used to quantify balance control performance. It was found that unpleasant auditory stimuli were associated with larger COP amplitude in the AP direction compared to the rest testing conditions. There were no significant interaction effects between 'auditory stimuli' and gender. These findings suggested that some specificities presented by auditory stimuli are important for balance control, and the effects of auditory stimuli on balance control were dependent on their affective components. Practitioner Summary: Findings from this study can aid in better understanding of the relationship between auditory stimuli and balance control. In particular, unpleasant auditory stimuli were found to result in poorer balance control and higher fall risks. Therefore, to prevent fall accidents, interventions should be developed to reduce exposures to unpleasant sound.

Head movement measurement: An alternative method for posturography studies

The present study evaluated the measurement of head movements as a valid method for postural emotional studies using the comparison of simultaneous recording of center of pressure (COP) sway as criterion. Thirty female students viewed a set of 12 pleasant, 12 unpleasant and 12 neutral pictures from the International Affective Picture System, repeated twice, using a block presentation procedure while standing on a force platform (AMTI AccuSway). Head movements were recorded using a webcam (©KPC139E) located in the ceiling in line with the force platform and a light-emitting diode (LED) placed on the top of the head. Open source software (CvMob 3.1) was used to process the data. High indices of correlation and coherence between head and COP sway were observed. In addition, pleasant pictures, compared with unpleasant pictures, elicited greater body sway in the anterior-posterior axis, suggesting an approach response to appetitive stimuli. Thus, the measurement of head movement can be an alternative or complementary method to recording COP for studying human postural changes.

Altered Functional Performance in Patients with Fibromyalgia

Fibromyalgia is a common chronic pain condition that exerts a considerable impact on patients' daily activities and quality of life.

Objectives: The main objective of the present study was to evaluate kinematic parameters of gait, functional performance, and balance in women with fibromyalgia syndrome.

Methods: The study included 26 female patients with fibromyalgia (49.2 ± 8.0 years) according to the criteria of the American College of Rheumatology, as well as 16 pain-free women (43.5 ± 8.5 years). Gait and balance parameters were extracted from video recordings of participants performing several motor tasks. Non-linear dynamic of body sway time series was also analyzed by computing the Hurst exponent. In addition, functional performance and clinical pain were obtained by using standardized motor tests (Berg's balance scale, 6-min walking test, timed up and go task, Romberg's balance test) and self-report questionnaires (Fibromyalgia Impact Questionnaire).

Results: Walking speed was significantly diminished (p < 0.001) in FM patients as compared to pain-free controls, probably due to significant reductions in stride length (p < 0.001) and cycle frequency (p < 0.001). Analyses of balance also revealed significant differences between fibromyalgia and pain-free controls on body sway in the medial-lateral and anterior-posterior axes (all ps < 0.01). Several parameters of gait and balance were significantly associated with high levels of pain, depression, stiffness, anxiety, and fatigue in fibromyalgia.

Conclusion: Our data revealed that both gait and balance were severely impaired in FM, and that subjective complaints associated with FM could contribute to functional disability in these patients. These findings suggest that optimal rehabilitation and fall prevention in fibromyalgia require a comprehensive assessment of both psychological responses to pain and physical impairments during postural control and gait.