Exercise-induced inflammation alters the perception and visual exploration of emotional interactions.

Introduction: The study aimed to investigate whether an exercise-induced pro-inflammatory response alters the perception as well as visual exploration of emotional body language in social interactions. Methods: In a within-subject design, 19 male, healthy adults aged between 19 and 33 years performed a downhill run for 45 min at 70% of their VO2max on a treadmill to induce maximal myokine blood elevations, leading to a pro-inflammatory status. Two control conditions were selected: a control run with no decline and a rest condition without physical exercise. Blood samples were taken before (T0), directly after (T1), 3 h after (T3), and 24 h after (T24) each exercise for analyzing the inflammatory response. 3 h after exercise, participants observed point-light displays (PLDs) of human interactions portraying four emotions (happiness, affection, sadness, and anger). Participants categorized the emotional content, assessed the emotional intensity of the stimuli, and indicated their confidence in their ratings. Eye movements during the entire paradigm and self-reported current mood were also recorded. Results: The downhill exercise condition resulted in significant elevations of measured cytokines (IL6, CRP, MCP-1) and markers for muscle damage (Myoglobin) compared to the control running condition, indicating a pro-inflammatory state after the downhill run. Emotion recognition rates decreased significantly after the downhill run, whereas no such effect was observed after control running. Participants' sensitivity to emotion-specific cues also declined. However, the downhill run had no effect on the perceived emotional intensity or the subjective confidence in the given ratings. Visual scanning behavior was affected after the downhill run, with participants fixating more on sad stimuli, in contrast to the control conditions, where participants exhibited more fixations while observing happy stimuli. Conclusion: Our study demonstrates that inflammation, induced through a downhill running model, impairs perception and emotional recognition abilities. Specifically, inflammation leads to decreased recognition rates of emotional content of social interactions, attributable to diminished discrimination capabilities across all emotional categories. Additionally, we observed alterations in visual exploration behavior. This confirms that inflammation significantly affects an individual's responsiveness to social and affective stimuli.

Recognition of emotional body language from dyadic and monadic point-light displays in 5-year-old children and adults.

Most child studies on emotion perception used faces and speech as emotion stimuli, but little is known about children's perception of emotions conveyed by body movements, that is, emotional body language (EBL). This study aimed to investigate whether processing advantages for positive emotions in children and negative emotions in adults found in studies on emotional face and term perception also occur in EBL perception. We also aimed to uncover which specific movement features of EBL contribute to emotion perception from interactive dyads compared with noninteractive monads in children and adults. We asked 5-year-old children and adults to categorize happy and angry point-light displays (PLDs), presented as pairs (dyads) and single actors (monads), in a button-press task. By applying representational similarity analyses, we determined intra- and interpersonal movement features of the PLDs and their relation to the participants' emotional categorizations. Results showed significantly higher recognition of happy PLDs in 5-year-olds and of angry PLDs in adults in monads but not in dyads. In both age groups, emotion recognition depended significantly on kinematic and postural movement features such as limb contraction and vertical movement in monads and dyads, whereas in dyads recognition also relied on interpersonal proximity measures such as interpersonal distance. Thus, EBL processing in monads seems to undergo a similar developmental shift from a positivity bias to a negativity bias, as was previously found for emotional faces and terms. Despite these age-specific processing biases, children and adults seem to use similar movement features in EBL processing.

Biomarkers in Endurance Exercise: Individualized Regulation and Predictive Value.

The high interindividual variability of exercise response complicates the efficient use of blood-based biomarkers in sports. To address this problem, a useful algorithm to characterize the individual regulation and predictive value of different candidate markers will be developed. Forty-nine participants completed two identical exercise trials. Blood samples were collected before, immediately after, 3 hours after, and 24 hours after completion of exercise. Plasma concentrations of interleukin (IL-) 1RA, IL-6, IL-8, IL-10, IL-15, creatine kinase (CK), cortisol, c-reactive protein (CRP), lactate dehydrogenase (LDH), and thiobarbituric acid reactive substances (TBARS) were measured. Individualized regulation was analyzed using k-means clustering and a Group Assignment Quality (GAQ) score. Regression trees with a bootstrapped-aggregated approach were used to assess the predictive qualities of the markers. For most of the markers studied, a distinction can be made between individuals who show a stronger or weaker response to a particular endurance training program. The regulation of IL-6, IL-8, IL-10, and CK exhibited a high degree of stability within the individuals. Regarding the predictive power of the markers, for all dependent variables, the most accurate predictions were obtained for cortisol and IL-8 based on the baseline value. For CK, a good prediction of recovery of maximal strength and subjective feeling of exhaustion can be made. For IL-1RA and TBARS, especially their reregulation can be predicted if the baseline level is known. Focusing individual variations in biomarker responses, our results suggest the combined use of IL-6, IL-8, IL-10, and CK for the personalized management of stress and recovery cycles following endurance exercise.

The multisensory nature of human action imagery.

Imagination can appeal to all our senses and may, therefore, manifest in very different qualities (e.g., visual, tactile, proprioceptive, or kinesthetic). One line of research addresses action imagery that refers to a process by which people imagine the execution of an action without actual body movements. In action imagery, visual and kinesthetic aspects of the imagined action are particularly important. However, other sensory modalities may also play a role. The purpose of the paper will be to address issues that include: (i) the creation of an action image, (ii) how the brain generates images of movements and actions, (iii) the richness and vividness of action images. We will further address possible causes that determine the sensory impression of an action image, like task specificity, instruction and experience. In the end, we will outline open questions and future directions.

Decoding spatiotemporal features of emotional body language in social interactions.

How are emotions perceived through human body language in social interactions? This study used point-light displays of human interactions portraying emotional scenes (1) to examine quantitative intrapersonal kinematic and postural body configurations, (2) to calculate interaction-specific parameters of these interactions, and (3) to analyze how far both contribute to the perception of an emotion category (i.e. anger, sadness, happiness or affection) as well as to the perception of emotional valence. By using ANOVA and classification trees, we investigated emotion-specific differences in the calculated parameters. We further applied representational similarity analyses to determine how perceptual ratings relate to intra- and interpersonal features of the observed scene. Results showed that within an interaction, intrapersonal kinematic cues corresponded to emotion category ratings, whereas postural cues reflected valence ratings. Perception of emotion category was also driven by interpersonal orientation, proxemics, the time spent in the personal space of the counterpart, and the motion-energy balance between interacting people. Furthermore, motion-energy balance and orientation relate to valence ratings. Thus, features of emotional body language are connected with the emotional content of an observed scene and people make use of the observed emotionally expressive body language and interpersonal coordination to infer emotional content of interactions.

When the timing is right: The link between temporal coupling in dyadic interactions and emotion recognition.

Affective states can be understood as dynamic interpersonal processes developing over time and space. When we observe emotional interactions performed by other individuals, our visual system anticipates how the action will unfold. Thus, it has been proposed that the process of emotion perception is not only a simulative but also a predictive process - a phenomenon described as interpersonal predictive coding. The present study investigated whether the recognition of emotions from dyadic interactions depends on a fixed spatiotemporal coupling of the agents. We used an emotion recognition task to manipulate the actions of two interacting point-light figures by implementing different temporal offsets that delayed the onset of one of the agent's actions (+0 ms, +500 ms, +1000 ms or + 2000 ms). Participants had to determine both the subjective valence and the emotion category (happiness, anger, sadness, affection) of the interaction. Results showed that temporal decoupling had a critical effect on both emotion recognition and the subjective impression of valence intensity: Both measures decreased with increasing temporal offset. However, these effects were dependent on which emotion was displayed. Whereas affection and anger sequences were impacted by the temporal manipulation, happiness and sadness were not. To further investigate these effects, we conducted post-hoc exploratory analyses of interpersonal movement parameters. Our findings complement and extend previous evidence by showing that the complex, noncoincidental coordination of actions within dyadic interactions results in a meaningful movement pattern and might serve as a fundamental factor in both detecting and understanding complex actions during human interaction.

Abdominal Obesity-Related Disturbance of Insulin Sensitivity Is Associated with CD8+ EMRA Cells in the Elderly.

Aging and overweight increase the risk of developing type 2 diabetes mellitus. In this cross-sectional study, we aimed to investigate the potential mediating role of T-EMRA cells and inflammatory markers in the development of a decreased insulin sensitivity. A total of 134 healthy older volunteers were recruited (age 59.2 (SD 5.6) years). T cell subpopulations were analyzed by flow cytometry. Furthermore, body composition, HOMA-IR, plasma tryptophan (Trp) metabolites, as well as cytokines and adipokines were determined. Using subgroup and covariance analyses, the influence of BMI on the parameters was evaluated. Moreover, correlation, multiple regression, and mediation analyses were performed. In the subgroup of participants with obesity, an increased proportion of CD8+EMRA cells and elevated concentrations of plasma kynurenine (KYN) were found compared to the lower-weight subgroups. Linear regression analysis revealed that an elevated HOMA-IR could be predicted by a higher proportion of CD8+EMRA cells and KYN levels. A mediation analysis showed a robust indirect effect of the Waist-to-hip ratio on HOMA-IR mediated by CD8+EMRA cells. Thus, the deleterious effects of abdominal obesity on glucose metabolism might be mediated by CD8+EMRA cells in the elderly. Longitudinal studies should validate this assumption and analyze the suitability of CD8+EMRA cells as early predictors of incipient prediabetes.

Physical Activity and Mental Health of Patients with Pulmonary Hypertension during the COVID-19 Pandemic.

The aim of the study was to analyze the effect of personal restrictions on physical activity, mental health, stress experience, resilience, and sleep quality in patients with pulmonary hypertension (PH) during the "lockdown" period of the COVID-19 pandemic. In total, 112 PH patients and 52 age-matched healthy control subjects completed a questionnaire on the topics of physical activity, mental health, resilience, and sleep quality. PH patients had significantly lower physical activity, mental health, and sleep quality compared to age-matched healthy controls. Physical activity positively correlated with mental health and sleep quality in the PH group. Mental wellbeing and life satisfaction could be predicted by total physical activity, sleep, stress level, and resilience. PH patients appeared as an especially vulnerable group, demanding interventions to promote an active lifestyle and protect mental health in these patients. This could be helpful in counseling on how to carry out physical activity while maintaining infection control.

Practice modality of motor sequences impacts the neural signature of motor imagery.

Motor imagery is conceptualized as an internal simulation that uses motor-related parts of the brain as its substrate. Many studies have investigated this sharing of common neural resources between the two modalities of motor imagery and motor execution. They have shown overlapping but not identical activation patterns that thereby result in a modality-specific neural signature. However, it is not clear how far this neural signature depends on whether the imagined action has previously been practiced physically or only imagined. The present study aims to disentangle whether the neural imprint of an imagined manual pointing sequence within cortical and subcortical motor areas is determined by the nature of this prior practice modality. Each participant practiced two sequences physically, practiced two other sequences mentally, and did a behavioural pre-test without any further practice on a third pair of sequences. After a two-week practice intervention, participants underwent fMRI scans while imagining all six sequences. Behavioural data demonstrated practice-related effects as well as very good compliance with instructions. Functional MRI data confirmed the previously known motor imagery network. Crucially, we found that mental and physical practice left a modality-specific footprint during mental motor imagery. In particular, activation within the right posterior cerebellum was stronger when the imagined sequence had previously been practiced physically. We conclude that cerebellar activity is shaped specifically by the nature of the prior practice modality.

Sensory features of mental images in the framework of human actions.

What determines the sensory impression of a self-generated motor image? Motor imagery is a process in which subjects imagine executing a body movement with a strong kinesthetic and/or visual component from a first-person perspective. Both sensory modalities can be combined flexibly to form a motor image. 90 participants of varying ages had to freely generate motor images from a large set of movements. They were asked to rate their kinesthetic as well as their visual impression, the perceived vividness, and their personal experience with the imagined movement. Data were subjected to correlational analyses, linear regressions, and representation similarity analyses. Results showed that both action characteristics and experience drove the sensory impression of motor images with a strong individual component. We conclude that imagining actions that impose varying demands can be considered as reexperiencing actions by using one's own sensorimotor representations that represent not only individual experience but also action demands.

Emotional expressivity of the observer mediates recognition of affective states from human body movements.

Research on human motion perception shows that people are highly adept at inferring emotional states from body movements. Yet, this process is mediated by a number of individual factors and experiences. Within this study, we tackle two questions. Firstly, we ask which part of the body transmits the key information that is used to infer affective states. Secondly, we address how the observer's own emotional expressivity influences the recognition process. We used two types of impoverished point-light displays depicting the same emotional interactions as either arm or trunk movements. Results showed that participants used different sources of information in an emotion-specific manner. Participants with richer self-reported emotional expressivity showed higher recognition accuracies overall but also benefited more from information delivered by arm gestures. We interpret our findings in terms of embodied simulation, suggesting that emotion perception constitutes a function of the expressing body and the individual observer.

Subjective vividness of motor imagery has a neural signature in human premotor and parietal cortex.

Motor imagery (MI) is the process in which subjects imagine executing a body movement with a strong kinesthetic component from a first-person perspective. The individual capacity to elicit such mental images is not universal but varies within and between subjects. Neuroimaging studies have shown that these inter-as well as intra-individual differences in imagery quality mediate the amplitude of neural activity during MI on a group level. However, these analyses were not sensitive to forms of representation that may not map onto a simple modulation of overall amplitude. Therefore, the present study asked how far the subjective impression of motor imagery vividness is reflected by a spatial neural code, and how patterns of neural activation in different motor regions relate to specific imagery impressions. During fMRI scanning, 20 volunteers imagined three different types of right-hand actions. After each imagery trial, subjects were asked to evaluate the perceived vividness of their imagery. A correlation analysis compared the rating differences and neural dissimilarity values of the rating groups separately for each region of interest. Results showed a significant positive correlation in the left vPMC and right IPL, indicating that these regions particularly reflect perceived imagery vividness in that similar rated trials evoke more similar neural patterns. A decoding analysis revealed that the vividness of the motor image related systematically to the action specificity of neural activation patterns in left vPMC and right SPL. Imagined actions accompanied by higher vividness ratings were significantly more distinguishable within these areas. Altogether, results showed that spatial patterns of neural activity within the human motor cortices reflect the individual vividness of imagined actions. Hence, the findings reveal a link between the subjective impression of motor imagery vividness and objective physiological markers.

Neural Underpinnings of the Perception of Emotional States Derived From Biological Human Motion: A Review of Neuroimaging Research.

Research on the perception of biological human motion shows that people are able to infer emotional states by observing body movements. This article reviews the methodology applied in fMRI research on the neural representation of such emotion perception. Specifically, we ask how different stimulus qualities of bodily expressions, individual emotional valence, and task instructions may affect the neural representation of an emotional scene. The review demonstrates the involvement of a variety of brain areas, thereby indicating how well the human brain is adjusted to navigate in multiple social situations. All stimulus categories (i.e., full-light body displays, point-light displays, and avatars) can induce an emotional percept and are associated with increased activation in an extensive neural network. This network seems to be organized around areas belonging to the so-called action observation network (PMC, IFG, and IPL) and the mentalizing network (TPJ, TP, dmPFC, and lOFC) as well as areas processing body form and motion (e.g., EBA, FBA, and pSTS). Furthermore, emotion-processing brain sites such as the amygdala and the hypothalamus seem to play an important role during the observation of emotional body expressions. Whereas most brain regions clearly display an increased response to emotional body movements in general, some structures respond selectively to negative valence. Moreover, neural activation seems to depend on task characteristics, indicating that certain structures are activated even when attention is shifted away from emotional body movements.

Task-Specificity of Muscular Responses During Motor Imagery: Peripheral Physiological Effects and the Legacy of Edmund Jacobson.

Motor imagery has become a key issue in cognitive neuroscience and particularly in fMRI research. However, peripheral physiological effects of motor imagery were already being studied a century ago with some research hypotheses even tracing back to Washburn (1916). This review focuses on research by Edmund Jacobson in the early 1930s. Jacobsen demonstrated that peripheral physiological effects rely on task-specific instructions: Bending the right arm elicits muscular responses in the right biceps, but not in the muscles of other limbs. This review discusses how Jacobsen examined this issue in a series of studies. This scientific spadework is worth recalling here because of its methodological innovations and its forward-looking discussion that even today, continues to be relevant for prospective research on this topic.

Perceived Intensity of Emotional Point-Light Displays is Reduced in Subjects with ASD.

One major characteristic of autism spectrum disorder (ASD) is problems with social interaction and communication. The present study explored ASD-related alterations in perceiving emotions expressed via body movements. 16 participants with ASD and 16 healthy controls observed video scenes of human interactions conveyed by point-light displays. They rated the valence of the depicted emotions in terms of their intensity and judged their confidence in their ratings. Results showed that healthy participants rated emotional interactions displaying positive emotionality as being more intense and were more confident about their ratings than ASD subjects. Results support the idea that patients with ASD have an altered perception of emotions. This extends research on subjective features (intensity, confidence) of emotion perception to the domain of emotional body movements and kinematics.

Effects of exercise training on pulmonary hemodynamics, functional capacity and inflammation in pulmonary hypertension.

Pulmonary hypertension (PH) is characterized by severe exercise limitation mainly attributed to the impairment of right ventricular function resulting from a concomitant elevation of pulmonary vascular resistance and pressure. The unquestioned cornerstone in the management of patients with pulmonary arterial hypertension (PAH) is specific vasoactive medical therapy to improve pulmonary hemodynamics and strengthen right ventricular function. Nevertheless, evidence for a beneficial effect of exercise training (ET) on pulmonary hemodynamics and functional capacity in patients with PH has been growing during the past decade. Beneficial effects of ET on regulating factors, inflammation, and metabolism have also been described. Small case-control studies and randomized clinical trials in larger populations of patients with PH demonstrated substantial improvements in functional capacity after ET. These findings were accompanied by several studies that suggested an effect of ET on inflammation, although a direct link between this effect and the therapeutic benefit of ET in PH has not yet been demonstrated. On this background, the aim of the present review is to describe current concepts regarding the effects of exercise on the pulmonary circulation and pathophysiological limitations, as well as the clinical and mechanistic effects of exercise in patients with PH.

Imagined and Executed Actions in the Human Motor System: Testing Neural Similarity Between Execution and Imagery of Actions with a Multivariate Approach.

Simulation theory proposes motor imagery (MI) to be a simulation based on representations also used for motor execution (ME). Nonetheless, it is unclear how far they use the same neural code. We use multivariate pattern analysis (MVPA) and representational similarity analysis (RSA) to describe the neural representations associated with MI and ME within the frontoparietal motor network. During functional magnetic resonance imaging scanning, 20 volunteers imagined or executed 3 different types of right-hand actions. Results of MVPA showed that these actions as well as their modality (MI or ME) could be decoded significantly above chance from the spatial patterns of BOLD signals in premotor and posterior parietal cortices. This was also true for cross-modal decoding. Furthermore, representational dissimilarity matrices of frontal and parietal areas showed that MI and ME representations formed separate clusters, but that the representational organization of action types within these clusters was identical. For most ROIs, this pattern of results best fits with a model that assumes a low-to-moderate degree of similarity between the neural patterns associated with MI and ME. Thus, neural representations of MI and ME are neither the same nor totally distinct but exhibit a similar structural geometry with respect to different types of action.

Motor imagery of hand actions: Decoding the content of motor imagery from brain activity in frontal and parietal motor areas.

How motor maps are organized while imagining actions is an intensely debated issue. It is particularly unclear whether motor imagery relies on action-specific representations in premotor and posterior parietal cortices. This study tackled this issue by attempting to decode the content of motor imagery from spatial patterns of Blood Oxygen Level Dependent (BOLD) signals recorded in the frontoparietal motor imagery network. During fMRI-scanning, 20 right-handed volunteers worked on three experimental conditions and one baseline condition. In the experimental conditions, they had to imagine three different types of right-hand actions: an aiming movement, an extension-flexion movement, and a squeezing movement. The identity of imagined actions was decoded from the spatial patterns of BOLD signals they evoked in premotor and posterior parietal cortices using multivoxel pattern analysis. Results showed that the content of motor imagery (i.e., the action type) could be decoded significantly above chance level from the spatial patterns of BOLD signals in both frontal (PMC, M1) and parietal areas (SPL, IPL, IPS). An exploratory searchlight analysis revealed significant clusters motor- and motor-associated cortices, as well as in visual cortices. Hence, the data provide evidence that patterns of activity within premotor and posterior parietal cortex vary systematically with the specific type of hand action being imagined.

Motor imagery of locomotion with an additional load: actual load experience does not affect differences between physical and mental durations.

Motor imagery relies strongly on motor representations. Currently, it is widely accepted that both the imagery and execution of actions share the same neural representations (Jeannerod, Neuroimage 14:S103-S109, 2001). Comparing mental with actual movement durations opens a window through which to examine motor representations and how they relate to cognitive motor processes. The present experiment examined mental durations reported by participants standing upright who imagined walking either with or without an additional load while actually carrying or not carrying that same load. Results showed a robust effect of longer durations when imagining the additional load during mental walking, whereas physical walking with an additional load did not extend movement durations accordingly. However, experiencing an actual load during imagery did not influence mental durations substantially. This dissociation of load-related effects can be interpreted as being due to an interaction of motor processes and their cognitive representation along with a reduction in neural activity in vestibular and somatosensory areas during imagery of locomotion. It is argued that this effect might be specific to locomotion and not generalize to a broader range of movements.

Anticipating action effects recruits audiovisual movement representations in the ventral premotor cortex.

When table tennis players anticipate the course of the ball while preparing their motor responses, they not only observe their opponents striking the ball but also listen to events such as the sound of racket-ball contact. Because visual stimuli can be detected more easily when accompanied by a sound, we assumed that complementary sensory audiovisual information would influence the anticipation of biological motion, especially when the racket-ball contact is not presented visually, but has to be inferred from continuous movement kinematics and an abrupt sound. Twenty-six observers were examined with fMRI while watching point-light displays (PLDs) of an opposing table tennis player. Their task was to anticipate the resultant ball flight. The sound was presented complementary to the veracious event or at a deviant time point in its kinematics. Results showed that participants performed best in the complementary condition. Using a region-of-interest approach, fMRI data showed that complementary audiovisual stimulation elicited higher activation in the left temporo-occipital middle temporal gyrus (MTGto), the left primary motor cortex, and the right anterior intraparietal sulcus (aIPS). Both hemispheres also revealed higher activation in the ventral premotor cortex (vPMC) and the pars opercularis of the inferior frontal gyrus (BA 44). Ranking the behavioral effect of complementary versus conflicting audiovisual information over participants revealed an association between the complementary information and higher activation in the right vPMC. We conclude that the recruitment of movement representations in the auditory and visual modalities in the vPMC can be influenced by task-relevant cross-modal audiovisual interaction.