‘Naltrexone Blocks Endorphins Released when Dancing in Synchrony’

Effects of mind-body therapies on depression among adolescents: a systematic review and network meta-analysis

Background

Depression poses significant threats to adolescents' health globally. Research has shown the potential of mind-body therapies to alleviate depression, but limited studies have directly compared the therapeutic effects of different types of mind-body therapies on adolescent depression and the optimal therapy remain unclear. Therefore, we conducted a systematic review and network meta-analysis of randomized controlled trials that met the inclusion criteria to explore the effectiveness of different types of mind-body therapies as interventions to improve depression among adolescents, and to identify the most effective interventions.

Methods

A comprehensive search of databases including PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus up to January 2024 was conducted to assess the impact of mind-body therapies on depression among adolescents. The risk of bias of the included studies was evaluated using Cochrane Review Manager 5.4. STATA 18.0 was used for network meta-analysis. The node-splitting method was used to test the local inconsistency of the network meta-analysis. Funnel plots and the Egger's test were utilized to assess the potential impact of bias in this study.

Result

This network meta-analysis included 9 randomized controlled trials involving a total of 955 subjects. The results indicated that yoga, dance therapy and Tai Chi were more effective than other mind-body therapies in reducing symptoms of depression among adolescents. Specifically, according to the SUCRA ranking, yoga was rated to be the optimal intervention for adolescents with depression (SCURA: 82.2%), followed by dance therapy (SCURA: 77.5%) and Tai Chi (SCURA: 64.9%).

Conclusion

This study revealed that mind-body therapies have positive effects on improving depression among adolescents. Yoga may be the most effective intervention among the different types of mind-body therapies. However, due to the small sample size of patients included, the certainty of the results was limited to some extent. Therefore, further investigation is necessary to strengthen the evidence base when more relevant studies become available.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024508774.

The psychophysiology of music-based interventions and the experience of pain

In modern times there is increasing acceptance that music-based interventions are useful aids in the clinical treatment of a range of neurological and psychiatric conditions, including helping to reduce the perception of pain. Indeed, the belief that music, whether listening or performing, can alter human pain experiences has a long history, dating back to the ancient Greeks, and its potential healing properties have long been appreciated by indigenous cultures around the world. The subjective experience of acute or chronic pain is complex, influenced by many intersecting physiological and psychological factors, and it is therefore to be expected that the impact of music therapy on the pain experience may vary from one situation to another, and from one person to another. Where pain persists and becomes chronic, aberrant central processing is a key feature associated with the ongoing pain experience. Nonetheless, beneficial effects of exposure to music on pain relief have been reported across a wide range of acute and chronic conditions, and it has been shown to be effective in neonates, children and adults. In this comprehensive review we examine the various neurochemical, physiological and psychological factors that underpin the impact of music on the pain experience, factors that potentially operate at many levels - the periphery, spinal cord, brainstem, limbic system and multiple areas of cerebral cortex. We discuss the extent to which these factors, individually or in combination, influence how music affects both the quality and intensity of pain, noting that there remains controversy about the respective roles that diverse central and peripheral processes play in this experience. Better understanding of the mechanisms that underlie music's impact on pain perception together with insights into central processing of pain should aid in developing more effective synergistic approaches when music therapy is combined with clinical treatments. The ubiquitous nature of music also facilitates application from the therapeutic environment into daily life, for ongoing individual and social benefit.

A review of psychological and neuroscientific research on musical groove

When listening to music, we naturally move our bodies rhythmically to the beat, which can be pleasurable and difficult to resist. This pleasurable sensation of wanting to move the body to music has been called "groove." Following pioneering humanities research, psychological and neuroscientific studies have provided insights on associated musical features, behavioral responses, phenomenological aspects, and brain structural and functional correlates of the groove experience. Groove research has advanced the field of music science and more generally informed our understanding of bidirectional links between perception and action, and the role of the motor system in prediction. Activity in motor and reward-related brain networks during music listening is associated with the groove experience, and this neural activity is linked to temporal prediction and learning. This article reviews research on groove as a psychological phenomenon with neurophysiological correlates that link musical rhythm perception, sensorimotor prediction, and reward processing. Promising future research directions range from elucidating specific neural mechanisms to exploring clinical applications and socio-cultural implications of groove.

The origins and function of musical performance

Music is widely recognised as a human universal, yet there is no agreed explanation for its function, or why and when it evolved. I summarise experimental evidence that the primary function of musicking lies in social bonding, both at the dyadic and community levels, via the effect that performing any form of music has on the brain's endorphin system (the principal neurohormonal basis for social bonding in primates). The many other functions associated with music-making (mate choice, pleasure, coalition signalling, etc) are all better understood as derivative of this, either as secondary selection pressures or as windows of evolutionary opportunity (exaptations). If music's function is primarily as an adjunct of the social bonding mechanism (a feature it shares with laughter, feasting, storytelling and the rituals of religion), then reverse engineering the problem suggests that the capacity for music-making most likely evolved with the appearance of archaic humans. This agrees well with anatomical evidence for the capacity to sing.

Banging the drum: evolutionary and cultural origins of music and its implications for psychiatry

SUMMARY

There is growing interest in music-based therapies for mental/behavioural disorders. We begin by reviewing the evolutionary and cultural origins of music, proceeding then to discuss the principles of evolutionary psychiatry, itself a growing a field, and how it may apply to music. Finally we offer some implications for the role of music and music-based therapies in clinical practice.

The Neuroscience of Dance: A Conceptual Framework and Systematic Review

Ancient and culturally universal, dance pervades many areas of life and has multiple benefits. In this article, we provide a conceptual framework and systematic review, as a guide for researching the neuroscience of dance. We identified relevant articles following PRISMA guidelines, and summarised and evaluated all original results. We identified avenues for future research in: the interactive and collective aspects of dance; groove; dance performance; dance observation; and dance therapy. Furthermore, the interactive and collective aspects of dance constitute a vital part of the field but have received almost no attention from a neuroscientific perspective so far. Dance and music engage overlapping brain networks, including common regions involved in perception, action, and emotion. In music and dance, rhythm, melody, and harmony are processed in an active, sustained pleasure cycle giving rise to action, emotion, and learning, led by activity in specific hedonic brain networks. The neuroscience of dance is an exciting field, which may yield information concerning links between psychological processes and behaviour, human flourishing, and the concept of eudaimonia.

Only empathy-related traits, not being mimicked or endorphin release, influence social closeness and prosocial behavior

Seminal studies suggest that being mimicked increases experienced social closeness and prosocial behavior to a mimicking confederate (i.e., interaction partner). Here we reexamine these results by considering the role of empathy-related traits, an indirect proxy for endorphin uptake, and their combined effects as an explanation for these results. 180 female participants were mimicked or anti-mimicked in an interaction with a confederate. The effects of being mimicked versus anti-mimicked in relation to empathy-related traits and endorphin release (assessed indirectly via pain tolerance) on experienced closeness and prosocial behavior were assessed using Bayesian analyses. Our results suggest that high individual empathy-related traits increase social closeness to the anti-mimicking and mimicking confederate and to one's romantic partner, as compared to mimicry alone. Results furthermore strongly suggest that high individual empathy-related traits increase prosocial behavior (donations and willingness to help) as compared to mimicry alone. These findings extend previous work by highlighting that empathy-related traits are more influential in creating positive effects on social closeness and prosocial behavior than a one-shot mimicking encounter.

Musical engagement as a duet of tight synchrony and loose interpretability

Joint engagement in music often facilitates positive social interaction, effectively shifting participants' perspective from the individual to the collective. The result is tight coordination and uniformity between participants, but at the same time, also remarkable flexibility and creativity. How does music achieve such a fine balance between the strict alignment necessary for coordination, and the substantial latitude necessary for experimentation? To address this question, I propose to analyze joint music engagement within the tight-loose theoretical framework broadly used in the social sciences. Tight-loose theory was originally developed for distinguishing between two archetypical cultural tendencies. On the one hand, tightness, which denotes stringent adherence to social norms, and on the other hand, looseness, which refers to a more flexible and less restrictive attitude towards norms. I posit that the flexible form of collaboration characteristic of musical interaction is due to a coexistence of tightness and looseness within joint engagement in music. I argue that the tight aspects of music can be attributed to its rhythmic structure, which requires continuous and precise temporal alignment between participants. Indeed, when experienced on its own, outside of a musical context, interpersonal synchrony has been repeatedly shown to enhance diverse positive social capacities such as bonding, collaboration and affiliation between interacting individuals, but at the expense of increasing conformity, blind obedience and even hostility towards non-group members. These effects are consistent with synchrony driving a tight interaction, inducing a sense of common group membership (CGM), which can endow music with necessary rigor and order. In contrast, the loose side of music may pertain to the ambiguity in meaning and intention expressed by music, which leaves ample room for interpretation and improvisation. I thus propose that the combined tight-loose nature of music, can simultaneously enhance positive social behaviors and reduce negative ones, leading to a tolerant form of group membership (TGM).

Opioid antagonism in humans: a primer on optimal dose and timing for central mu-opioid receptor blockade

Non-human animal studies outline precise mechanisms of central mu-opioid regulation of pain, stress, affiliation and reward processing. In humans, pharmacological blockade with non-selective opioid antagonists such as naloxone and naltrexone is typically used to assess involvement of the mu-opioid system in such processing. However, robust estimates of the opioid receptor blockade achieved by opioid antagonists are missing. Dose and timing schedules are highly variable and often based on single studies. Here, we provide a detailed analysis of central opioid receptor blockade after opioid antagonism based on existing positron emission tomography data. We also create models for estimating opioid receptor blockade with intravenous naloxone and oral naltrexone. We find that common doses of intravenous naloxone (0.10-0.15 mg/kg) and oral naltrexone (50 mg) are more than sufficient to produce full blockade of central MOR (>90% receptor occupancy) for the duration of a typical experimental session (~60 min), presumably due to initial super saturation of receptors. Simulations indicate that these doses also produce high KOR blockade (78-100%) and some DOR blockade (10% with naltrexone and 48-74% with naloxone). Lower doses (e.g., 0.01 mg/kg intravenous naloxone) are estimated to produce less DOR and KOR blockade while still achieving a high level of MOR blockade for ~30 min. The models and simulations form the basis of two novel web applications for detailed planning and evaluation of experiments with opioid antagonists. These tools and recommendations enable selection of appropriate antagonists, doses and assessment time points, and determination of the achieved receptor blockade in previous studies.

Five studies evaluating the impact on mental health and mood of recalling, reading, and discussing fiction

Does reading fiction improve mental health and well-being? We present the results of five studies that evaluated the impact of five forms of exposure to fiction. These included the effects of recalling reading fiction, of being prescribed fiction, of discussing fiction relative to non-fiction, and of discussing literary fiction relative to best-seller fiction. The first three studies directly recruited participants; the final two relied on scraped social media data from Reddit and Twitter. Results show that fiction can have a positive impact on measures of mood and emotion, but that a process of mnemonic or cognitive consolidation is required first: exposure to fiction does not, on its own, have an immediate impact on well-being.

Relationships Between Early Maternal Warmth and Social Connection: A Randomized Clinical Trial With Naltrexone

OBJECTIVE

Early experiences of having received maternal warmth predict responses to opportunities to connect with others later in life. However, the understanding of neurochemical mechanisms by which such relationships emerge remains incomplete. Endogenous opioids, involved in social connection in both animals and humans, may contribute to this link. Therefore, the current study examined a) relationships between early maternal warmth and brain and self-report responses to novel social targets (i.e., outcomes that may promote social connection) and b) the effect of the opioid antagonist, naltrexone, on such relationships.

METHODS

Eighty-two adult participants completed a retrospective report of early maternal warmth. On a second visit, participants were randomized to 50 mg of oral naltrexone (n = 42) or placebo (n = 40), followed by a magnetic resonance imaging scan where functional brain activity in response to images of novel social targets (strangers) was assessed. Approximately 24 hours later, participants reported on their feelings of social connection since leaving the scanner.

RESULTS

In the placebo condition, greater early maternal warmth was associated with less dorsal anterior cingulate cortex, anterior insula, ventral striatum, and amygdala activity in response to images of novel social targets (r values ≥ -0.360, p values ≤ .031), and greater feelings of social connection (r = 0.524, p < .001) outside of the laboratory. The same relationships, however, were not present in the naltrexone condition.

CONCLUSIONS

Results highlight relationships between early maternal warmth and responses to the social world at large and suggest that opioids might contribute to social connection by supporting the buffering effects of warm early life experiences on social connection later in life.Trial Registration: Clinical Trials NCT02818036.

Laughter influences social bonding but not prosocial generosity to friends and strangers

Humans deploy a number of specific behaviours for forming social bonds, one of which is laughter. However, two questions have not yet been investigated with respect to laughter: (1) Does laughter increase the sense of bonding to those with whom we laugh? and (2) Does laughter facilitate prosocial generosity? Using changes in pain threshold as a proxy for endorphin upregulation in the brain and a standard economic game (the Dictator Game) as an assay of prosociality, we show that laughter does trigger the endorphin system and, through that, seems to enhance social bonding, but it does not reliably influence donations to others. This suggests that social bonding and prosociality may operate via different mechanisms, or on different time scales, and relate to different functional objectives.

Cochlear SGN neurons elevate pain thresholds in response to music

The C-tactile (CLTM) peripheral nervous system is involved in social bonding in primates and humans through its capacity to trigger the brain’s endorphin system. Since the mammalian cochlea has an unusually high density of similar neurons (type-II spiral ganglion neurons, SGNs), we hypothesise that their function may have been exploited for social bonding by co-opting head movements in response to music and other rhythmic movements of the head in social contexts. Music provides one of many cultural behavioural mechanisms for ‘virtual grooming’ in that it is used to trigger the endorphin system with many people simultaneously so as to bond both dyadic relationships and large groups. Changes in pain threshold across an activity are a convenient proxy assay for endorphin uptake in the brain, and we use this, in two experiments, to show that pain thresholds are higher when nodding the head than when sitting still.

Effects of social support on performance outputs and perceived difficulty during physical exercise

Perceptions of social support influence adaptive self-regulatory processes that maintain health, produce feelings, and motivate behavior. Although associations between sociality and health are increasingly well-understood, there is little systematic research into the effects of social support on fatigue, physical discomfort, exertion, and output regulation in physical activity. We conducted an experimental study to investigate the effect of social support on performance and perceived difficulty in a handgrip force task while controlling for audience and reputational factors. Effects were compared with those of another established psychogenic performance enhancer (a placebo ergogenic supplement). During handgrip trials over varying levels of objective difficulty, participants viewed photographs of a support figure or stranger while in a placebo or control condition. Results revealed a significant main effect of the social support cue on handgrip performance outputs, and a significant interaction with objective trial difficulty - relative to the stranger cue, the support-figure cue significantly increased handgrip performance outputs and the effect was larger in more objectively difficult trials. Moreover, despite producing greater handgrip outputs, participants perceived trials to be significantly less difficult in the social support condition. Though there was a non-significant main effect of placebo (vs. control) on performance outputs, participants perceived trials in the placebo condition to be significantly less difficult. The research contributes new evidence and theory on the role of perceived social support - an important (energetic) resource - in human performance and motivates further enquiry into how cues to support alter perceived effort and performance outputs in strenuous physical challenges.

Mini-review: A possible role for galanin in post-traumatic stress disorder

Several neuroendocrine systems have been implicated in post-traumatic stress disorder, including the mesocortical and mesolimbic dopamine, the norepinephrine, the β-endorphin, the serotonin, and the oxytocin systems. The interaction between these different systems remains, however, largely unknown and a generally accepted unifying theory is thus far lacking. In this review, we suggest that galanergic suppression of dopaminergic neurons in the ventral tegmental may constitute the missing link in a post-traumatic feedback loop. In addition, we address the literature on the negative cross-antagonism in this brain region between the galanin 1 and μ-opioid receptors, which suggests that behavioural patterns which stimulate β-endorphin, a natural μ-opioid receptors ligand, secretion may provide novel avenues for the treatment and prevention of PTSD, as well as for recruitment, training, and leadership processes in high-stress/high-risk professions such as the military, first responders and the police.

The Effects of Synchrony on Group Moral Hypocrisy

Humans have evolved various social behaviors such as interpersonal motor synchrony (i.e., matching movements in time), play and sport or religious ritual that bolster group cohesion and facilitate cooperation. While important for small communities, the face-to-face nature of such technologies makes them infeasible in large-scale societies where risky cooperation between anonymous individuals must be enforced through moral judgment and, ultimately, altruistic punishment. However, the unbiased applicability of group norms is often jeopardized by moral hypocrisy, i.e., the application of moral norms in favor of closer subgroup members such as key socioeconomic partners and kin. We investigated whether social behaviors that facilitate close ties between people also promote moral hypocrisy that may hamper large-scale group functioning. We recruited 129 student subjects that either interacted with a confederate in the high synchrony or low synchrony conditions or performed movements alone. Subsequently, participants judged a moral transgression committed by the confederate toward another anonymous student. The results showed that highly synchronized participants judged the confederate’s transgression less harshly than the participants in the other two conditions and that this effect was mediated by the perception of group unity with the confederate. We argue that for synchrony to amplify group identity in large-scale societies, it needs to be properly integrated with morally compelling group symbols that accentuate the group’s overarching identity (such as in religious worship or military parade). Without such contextualization, synchrony may create bonded subgroups that amplify local preferences rather than impartial and wide application of moral norms.

Blocking mu-opioid receptors inhibits social bonding in rituals

Religious rituals are universal human practices that play a seminal role in community bonding. In two experiments, we tested the role of mu-opioids as the active factor fostering social bonding. We used a mu-opioid blocker (naltrexone) in two double-blind studies of rituals from different religious traditions. We found the same effect across both studies, with naltrexone leading to significantly lower social bonding compared with placebo. These studies suggest that mu-opioids play a significant role in experiences of social bonding within ritual contexts.

The Neurobiology of Social Distance

Never before have we experienced social isolation on such a massive scale as we have in response to coronavirus disease 2019 (COVID-19). However, we know that the social environment has a dramatic impact on our sense of life satisfaction and well-being. In times of distress, crisis, or disaster, human resilience depends on the richness and strength of social connections, as well as on active engagement in groups and communities. Over recent years, evidence emerging from various disciplines has made it abundantly clear: perceived social isolation (i.e., loneliness) may be the most potent threat to survival and longevity. We highlight the benefits of social bonds, the choreographies of bond creation and maintenance, as well as the neurocognitive basis of social isolation and its deep consequences for mental and physical health.

Music as a coevolved system for social bonding

Why do humans make music? Theories of the evolution of musicality have focused mainly on the value of music for specific adaptive contexts such as mate selection, parental care, coalition signaling, and group cohesion. Synthesizing and extending previous proposals, we argue that social bonding is an overarching function that unifies all of these theories, and that musicality enabled social bonding at larger scales than grooming and other bonding mechanisms available in ancestral primate societies. We combine cross-disciplinary evidence from archaeology, anthropology, biology, musicology, psychology, and neuroscience into a unified framework that accounts for the biological and cultural evolution of music. We argue that the evolution of musicality involves gene-culture coevolution, through which proto-musical behaviors that initially arose and spread as cultural inventions had feedback effects on biological evolution due to their impact on social bonding. We emphasize the deep links between production, perception, prediction, and social reward arising from repetition, synchronization, and harmonization of rhythms and pitches, and summarize empirical evidence for these links at the levels of brain networks, physiological mechanisms, and behaviors across cultures and across species. Finally, we address potential criticisms and make testable predictions for future research, including neurobiological bases of musicality and relationships between human music, language, animal song, and other domains. The music and social bonding (MSB) hypothesis provides the most comprehensive theory to date of the biological and cultural evolution of music.

Structure and function in human and primate social networks: implications for diffusion, network stability and health

The human social world is orders of magnitude smaller than our highly urbanized world might lead us to suppose. In addition, human social networks have a very distinct fractal structure similar to that observed in other primates. In part, this reflects a cognitive constraint, and in part a time constraint, on the capacity for interaction. Structured networks of this kind have a significant effect on the rates of transmission of both disease and information. Because the cognitive mechanism underpinning network structure is based on trust, internal and external threats that undermine trust or constrain interaction inevitably result in the fragmentation and restructuring of networks. In contexts where network sizes are smaller, this is likely to have significant impacts on psychological and physical health risks.

Opioid receptor blockade inhibits self-disclosure during a closeness-building social interaction

Social ties are critical to human health and well-being; thus, it is important to gain a better understanding of the neurobiological mechanisms involved in the development of interpersonal closeness. Prior research indicates that endogenous opioids may play a role in social affiliation by elaborating feelings of social connection and warmth; however, it is not currently known whether opioids mediate affiliative behavior and emerging feelings of closeness in humans at the relationship initiation stage. This randomized, double-blind study examined opioidergic processes in the context of a naturalistic, face-to-face social interaction. Eighty pairs of unacquainted participants (final N = 159 due to removal of one dyad member from analysis) received either 50 mg of the opioid receptor antagonist naltrexone or placebo prior to completing a closeness-building exercise centered on escalating self-disclosure (sharing of personal information about the self). Compared to the placebo group, naltrexone participants held lower social reward expectations prior to the interaction, engaged in less intimacy-fostering behavior (self-disclosure) during the interaction, and reported wanting less closeness with their partner. Feelings of social connection were not significantly lower in the naltrexone group. However, placebo participants experienced improvements in mood after the closeness-building task whereas naltrexone participants did not. These findings suggest that endogenous opioids may contribute to behavioral, affective, and motivational processes related to the development of initial closeness.

A novel theory on the predictive value of variation in the β-endorphin system on the risk and severity of PTSD

Despite growing interest in genetic and psychosocial indicators of heightened susceptibility to posttraumatic stress disorder (PTSD), a predictive model, which explains why some individuals develop PTSD in response to life-threatening traumatic events, while others, when faced with the same or similar experiences, do not, has thus far remained out of reach. In this paper, we review the literature on gene-environment interactions in β-endorphin system functioning with regard to PTSD and suggest that variation, both genetic and with regard to environmental stimuli, in systems which, like the β-endorphin system, distort human perception of life-threatening traumatic experiences may account for some of the variance in resilience to the disorder. Given the role of β-endorphin in both social connections and physical exercise, this becomes especially relevant with regard to military selection, training, and leadership processes.

Naltrexone alters responses to social and physical warmth: implications for social bonding

Socially warm experiences, when one feels connected to others, have been linked with physical warmth. Opioids, hypothesized to support social bonding with close others and, separately, physical warmth, may underlie both experiences. In order to test this hypothesis, 80 participants were randomly assigned to the opioid antagonist, naltrexone or placebo before neural and emotional responses to social and physical warmth were collected. Social and physical warmth led to similar increases in ventral striatum (VS) and middle-insula (MI) activity. Further, feelings of social connection were positively related to neural activity to social warmth. However, naltrexone (vs placebo) disrupted these effects by (i) reducing VS and MI activity to social and physical warmth, (ii) erasing the subjective experience-brain association to social warmth and (iii) disrupting the neural overlap between social and physical warmth. Results provide additional support for the theory that social and physical warmth share neurobiological, opioid receptor-dependent mechanisms and suggest multiple routes by which social connections may be maintained.

The Influence of Endogenous Opioids on the Relationship between Testosterone and Romantic Bonding

The endogenous opioid system has received attention and extensive research for its effects on reward, pleasure, and pain. However, relative to other neurochemicals, such as oxytocin, vasopressin and dopamine, the function of opioids in regulating human attachment, sociosexuality, and other aspects of human sociality has not received much consideration. For example, nonapeptides (oxytocin and vasopressin) have been extensively studied in animals and humans for their possible roles in mother-offspring attachment, romantic attachment, fatherhood, and social cognition. Likewise, others have proposed models wherein oxytocin and vasopressin are moderators of the relationship between steroid hormones and human social behaviors. Recently, opioids have generated renewed interest in relation to social pain, and importantly, the brain opioid hypothesis of social attachment (BOTSA), which suggests that endogenous opioids are a key implementer in primate and human bonding, has received some support. Here we focus on romantic bonds by proposing that endogenous opioids are an important mechanism mediating reproductive trade-offs through their inhibitory effects on testosterone production.

Sharing the social world via intersubject neural synchronisation

Sociability and capability of shared mental states are hallmarks of the human species, and pursuing shared goals oftentimes requires coordinating both behaviour and mental states. Here we review recent work using indices of intersubject neural synchronisation for measuring similarity of mental states across individuals. We discuss the methodological advances and limitations in the analyses based on intersubject synchrony, and discuss how these kinds of model-free analysis techniques enable the investigation of the brain basis of complex social processes. We argue that similarity of brain activity across individuals can be used, under certain conditions, to index the similarity of their subjective states of consciousness, and thus be used for investigating brain basis of mutual understanding and cooperation.

The Effects of Social Support on Strenuous Physical Exercise

In humans, socio-environmental cues play an important role in determining adaptive psychophysiological states and behaviours. In sport and exercise, cues to cohesive groups and close, supportive relationships are ubiquitous, possibly because of their effects on neurobiological mechanisms underlying physical performance. Clinical research has shown that the presence of supportive others can lead to reductions in perceptions of pain, while research from sport and exercise science has shown that pain and physical fatigue occupy ranges on a single spectrum of physical discomfort, which works to regulate outputs during strenuous physical exertion. Given the similar neurobiological underpinnings of pain and fatigue, the involvement of both in the self-regulation of strenuous physical outputs, and the effects of social support on perceptions of pain and neurophysiological stress responses more generally, we hypothesised that perceptions of social support affect outputs during strenuous physical exercise by altering activity in self-regulatory mechanisms involved in perceptions of pain and fatigue. We used a between-subjects experimental design to test this hypothesis, varying participants' social support and measuring physical outputs and perceptions of physical discomfort and exertion during a series of maximum-effort cycling bouts. Analyses showed that participants in the social support condition produced greater initial outputs and steeper declines over time, compared to controls. This effect was moderated by participant neuroticism; an important predictor of how individuals react to social support. We discuss these findings in terms of proposed causal mechanisms linking supportive, cohesive social environments with self-regulation and physical performance.