Effects of different kinds of couple interaction on cortisol and heart rate responses to stress in women

A systematic review and multivariate meta-analysis of the physical and mental health benefits of touch interventions

Receiving touch is of critical importance, as many studies have shown that touch promotes mental and physical well-being. We conducted a pre-registered (PROSPERO: CRD42022304281) systematic review and multilevel meta-analysis encompassing 137 studies in the meta-analysis and 75 additional studies in the systematic review (n = 12,966 individuals, search via Google Scholar, PubMed and Web of Science until 1 October 2022) to identify critical factors moderating touch intervention efficacy. Included studies always featured a touch versus no touch control intervention with diverse health outcomes as dependent variables. Risk of bias was assessed via small study, randomization, sequencing, performance and attrition bias. Touch interventions were especially effective in regulating cortisol levels (Hedges' g = 0.78, 95% confidence interval (CI) 0.24 to 1.31) and increasing weight (0.65, 95% CI 0.37 to 0.94) in newborns as well as in reducing pain (0.69, 95% CI 0.48 to 0.89), feelings of depression (0.59, 95% CI 0.40 to 0.78) and state (0.64, 95% CI 0.44 to 0.84) or trait anxiety (0.59, 95% CI 0.40 to 0.77) for adults. Comparing touch interventions involving objects or robots resulted in similar physical (0.56, 95% CI 0.24 to 0.88 versus 0.51, 95% CI 0.38 to 0.64) but lower mental health benefits (0.34, 95% CI 0.19 to 0.49 versus 0.58, 95% CI 0.43 to 0.73). Adult clinical cohorts profited more strongly in mental health domains compared with healthy individuals (0.63, 95% CI 0.46 to 0.80 versus 0.37, 95% CI 0.20 to 0.55). We found no difference in health benefits in adults when comparing touch applied by a familiar person or a health care professional (0.51, 95% CI 0.29 to 0.73 versus 0.50, 95% CI 0.38 to 0.61), but parental touch was more beneficial in newborns (0.69, 95% CI 0.50 to 0.88 versus 0.39, 95% CI 0.18 to 0.61). Small but significant small study bias and the impossibility to blind experimental conditions need to be considered. Leveraging factors that influence touch intervention efficacy will help maximize the benefits of future interventions and focus research in this field.

Alpha interbrain synchrony during mediated interpersonal touch

Interpersonal touch plays a crucial role in human communication, development, and wellness. Mediated interpersonal touch (MIT), a technology to distance or virtually simulated interpersonal touch, has received significant attention to counteract the negative consequences of touch deprivation. Studies investigating the effectiveness of MIT have primarily focused on self-reporting or behavioral correlates. It is largely unknown how MIT affects neural processes such as interbrain functional connectivity during human interactions. Given how users exchange haptic information simultaneously during interpersonal touch, interbrain functional connectivity provides a more ecologically valid way of studying the neural correlates associated with MIT. In this study, a palm squeeze task is designed to examine interbrain synchrony associated with MIT using EEG-based hyperscanning methodology. The phase locking value (PLV) index is used to measure interbrain synchrony. Results demonstrate that MIT elicits a significant increase in alpha interbrain synchronization between participants' brains. Especially, there was a significant difference in the alpha PLV indices between no MIT and MIT conditions in the early stage (130-470 ms) of the interaction period (t-test, p < 0.05). Given the role that alpha interbrain synchrony plays during social interaction, a significant increase in PLV index during MIT interaction seems to indicate an effect of social coordination. The findings and limitations of this study are further discussed, and perspectives on future research are provided.

Social support of virtual characters reduces pain perception

BACKGROUND

Psychosocial factors, such as social support, can reduce pain. Virtual reality (VR) is a powerful tool to decrease pain, but social factors in VR-based pain analgesia have rarely been studied. Specifically, it is unclear whether social support by virtual characters can reduce pain and whether the perceived control behind virtual characters (agency) and varying degrees of social cues impact pain perception.

METHODS

Healthy participants (N = 97) received heat pain stimulation while undergoing four within-subject conditions in immersive VR: (1) virtual character with a low number of social cues (virtual figure) provided verbal support, (2) virtual character with a high number of social cues (virtual human) provided verbal support, (3) no social support (hearing neutral words), (4) no social support. Perceived agency of the virtual characters served as between-subjects factor. Participants in the avatar group were led to believe that another participant controlled the virtual characters. Participants in the agent group were told they interacted with a computer. However, in both conditions, virtual characters were computer-controlled. Pain ratings, psychophysiological measurements and presence ratings were recorded.

RESULTS

Virtual social support decreased pain intensity and pain unpleasantness ratings but had no impact on electrodermal activity nor heart rate. A virtual character with a high number of social cues led to lower pain unpleasantness and higher feelings of presence. Agency had no significant impact.

CONCLUSIONS

Virtual characters providing social support can reduce pain independent of perceived agency. A more human visual appearance can have beneficial effects on social pain modulation by virtual characters.

SIGNIFICANCE

Social influences are important factors in pain modulation. The current study demonstrated analgesic effects through verbal support provided by virtual characters and investigated modulating factors. A more human appearance of a virtual character resulted in a higher reduction of pain unpleasantness. Importantly, agency of the virtual characters had no impact. Given the increasing use of digital health interventions, the findings suggest a positive impact of virtual characters for digital pain treatments.

Out of touch? How trauma shapes the experience of social touch - Neural and endocrine pathways

Trauma can shape the way an individual experiences the world and interacts with other people. Touch is a key component of social interactions, but surprisingly little is known about how trauma exposure influences the processing of social touch. In this review, we examine possible neurobiological pathways through which trauma can influence touch processing and lead to touch aversion and avoidance in trauma-exposed individuals. Emerging evidence indicates that trauma may affect sensory touch thresholds by modulating activity in the primary sensory cortex and posterior insula. Disturbances in multisensory integration and oxytocin reactivity combined with diminished reward-related and anxiolytic responses may induce a bias towards negative appraisal of touch contexts. Furthermore, hippocampus deactivation during social touch may reflect a dissociative state. These changes depend not only on the type and severity of the trauma but also on the features of the touch. We hypothesise that disrupted touch processing may impair social interactions and confer elevated risk for future stress-related disorders.

Touch and look: The role of affective touch in promoting infants' attention towards complex visual scenes

In a complex social environment, stimuli from different sensory modalities need to be integrated to decode communicative meanings. From very early in life, infants have to combine a multitude of sensory features with social and affective attributes. Of all senses, touch constitutes a privileged channel to carry affective-motivational meanings and foster social connection. In the present study, we investigate whether sharing sensory stimulation that varies for its affective value differentially affects infants' attention towards visual stimuli. 6 to 11-month-old infants (N = 42) were familiarized with two characters respectively matched with tactile (affective or non-affective) and auditory stimulation; then repeatedly exposed to scenes where the two characters moved towards target objects. Our results showed a main effect of stimulation (sound vs. touch) on looking times during familiarization, with longer looking times when sound is provided. During scenes presentation, a main effect of the type of touch (affective vs. non affective) emerged, with longer looking times in infants that previously experienced affective touch, suggesting that this sensory experience may critically engage the self and modulate infant attention. Overall, these findings suggest that while sound acts as attention getter, affective touch supports sustained attention towards complex visual scenes beyond the stimulation period itself.

A narrative review of research linking non-sexual social touch to sleep quality

This narrative review describes the current state of the literature that has examined associations between non-sexual social touch (i.e., affectionate touch, touch therapies, touch with animals and inanimate objects that mimic social touch) and sleep quality. It also highlights areas for future research to clarify the links and to identify underlying mechanisms. Most existing studies have focussed on and shown positive effects of touch therapies (e.g., massage, therapeutic touch) on sleep quality in clinical populations. Although there are fewer studies examining how other forms of social touch are linked with sleep quality, the existing research provides preliminary evidence supporting affectionate touch (e.g., hugging, skin-to-skin contact) and tactile contact with animals (e.g., dogs) and objects that mimic social touch (e.g., robots, weighted blankets) as predictors of better sleep quality, while touch deprivation and touch aversion are associated with worse sleep quality. Informed by the existing literature, we additionally reviewed potential relational-cognitive (e.g., felt-security) and neurobiological (e.g., oxytocin) mechanisms likely to underlie associations between social touch and sleep quality. Overall, current research supports associations between non-sexual social touch and sleep quality. However, future research is needed to establish these links for specific forms of social touch (and in various populations), to test explanatory mechanisms, and to identify boundary conditions. Understanding associations between non-sexual social touch and sleep quality can inform the development of touch-based interventions to improve sleep quality and health.

The Development of Stress Reactivity and Regulation in Children and Adolescents

Adversity experienced in early life can have detrimental effects on physical and mental health. One pathway in which these effects occur is through the hypothalamic-pituitary-adrenal (HPA) axis, a key physiological stress-mediating system. In this review, we discuss the theoretical perspectives that guide stress reactivity and regulation research, the anatomy and physiology of the axis, developmental changes in the axis and its regulation, brain systems regulating stress, the role of genetic and epigenetics variation in axis development, sensitive periods in stress system calibration, the social regulation of stress (i.e., social buffering), and emerging research areas in the study of stress physiology and development. Understanding the development of stress reactivity and regulation is crucial for uncovering how early adverse experiences influence mental and physical health.

Interpersonal touch and the importance of romantic partners for older adults' neuroendocrine health

Interpersonal touch is an essential aspect of human interaction that has the ability to regulate physiological stress responses. Prolonged exposure to stress can have cumulative multiphysiological effects; for example, allostatic load. Despite the increased susceptibility of social isolation for older adults, there is a paucity of research on the efficacy of touch in regulating stress responses among this population. It is also unknown whether touch confers benefits regardless of the person with whom it is shared. This study investigates the difference in physiological stress based on the frequency of touch (hugs, holding, or other close physical contact) shared with romantic partners as compared to other close adults (family, friends, and neighbours) in an older adult population. Data were analysed from 1419 respondents (aged 57-85 years) of the National Social Life, Health, and Aging Project (NSHAP) in 2005-2006. Principal components analysis determined whether the eight markers of allostatic load measured in the NSHAP function as a singular system or as distinct components. Analyses revealed three components of allostatic load: metabolic, cardiovascular, and neuroendocrine health. The results of multiple regression revealed that a higher frequency of interpersonal touch shared with romantic partners was associated with better neuroendocrine health (β = 0.13, p = 0.004) following adjustment for a variety of covariates (but not with better metabolic or cardiovascular health), with no associations apparent for touch from other close adults. These findings highlight the importance of promoting interpersonal touch with romantic partners for older adults' neuroendocrine health.

Topography and relationship-specific social touching in individuals displaying body image disturbances

Interpersonal touch is intimately related to the emotional bond between the touch giver and the touch receiver. Which bodily regions we touch in those individuals in our social network is relationship specific. Perception of interpersonal touch is altered in psychiatric disorders characterised by body image disturbances (BIDs). Here, we examined whether the 'imagined' experience of social touch in individuals with BIDs is body topography- and relationship-specific. By using an interactive media mobile App, the Virtual Touch Toolkit, high versus low levels of BIDs participants completed heatmaps of full-body virtual avatars, to indicate the body regions they find soothing/unpleasant to be touched by a loved one versus an acquaintance. Self-reports of interoceptive awareness and dysmorphic concerns were also measured. Overall, imagined touch was rated as the most soothing when received from a loved one, and also when this was delivered to 'social' body regions. The importance of the social relationship for the imagined tactile interactions was particularly evident for the high levels of BIDs group, with greater problems with interoceptive awareness predicting higher soothing touch ratings when this was received by a loved one. Despite the evidence that imagined bodily contacts between meaningful people is the most pleasant for socially acceptable bodily regions, our findings may suggest a greater sensitivity to relation-specific bodily patterns of social touch particularly in the high level of BIDs group. Heightened interoceptive awareness may also play a key role in this experience of bodily affective contacts. Future research for body-oriented therapy for BIDs is encouraged to systematically probe the efficacy of imagined social touch interaction protocols which use more plausible, ecological, scenarios where touch is delivered by loved ones and to socially acceptable bodily regions.

Self-Awareness of Goals Task (SAGT) and Planning Skills: The Neuroscience of Decision Making

A goal's self-awareness and the planning to achieve it drive decision makers. Through a neuroscientific approach, this study explores the self-awareness of goals by analyzing the explicit and implicit processes linked to the ability to self-represent goals and sort them via an implicit dominant key. Thirty-five professionals performed a novel and ecological decision-making task, the Self-Awareness of Goals Task (SAGT), aimed at exploring the (i) self-representation of the decision-making goals of a typical working day; (ii) self-representation of how these goals were performed in order of priority; (iii) temporal sequence; and (iv) in terms of their efficacy. Electrophysiological (i.e., alpha, beta, and gamma band), autonomic, behavioral, and self-report data (General Decision Making Style and Big Five Inventory) are collected. Higher self-awareness of goals by time as well as efficacy and the greater activation of alpha, beta, and gamma bands in the temporoparietal brain area were found. Correlations reported positive associations between the self-awareness of goals via a time and dependent decision-making style and a conscientious personality, but also between the self-awareness of goals via an efficacy and rational decision-making style. The results obtained in this study suggest that the SAGT could activate recursive thinking in the examinee and grasp individual differences in self-representation and aware identification of decision-making goals.

Evidence for Sex Differences in Depression, Sexual Attitudes, and Impulsivity as Predictors of Breaking Shelter-in-Place Orders During the COVID-19 Pandemic

Although the call to understand how sexual behaviors have been impacted by the COVID-19 pandemic has been established as an important area of study, research examining the extent to which gender, sexual attitudes, impulsivity, and psychological distress predicted breaking shelter-in-place (SIP) orders to engage in sexual behaviors with partners residing outside the home is undefined. Obtaining a deeper examination of the variables which predict risky sexual behaviors during SIP has important implications for future research at the intersection of public health, sexuality, and mental health. This study addressed the gap in the literature by considering how partnered sexual behaviors may be used during the COVID-19 pandemic to alleviate stress, as measured by breaking SIP orders for the pursuit of sexual intercourse. Participants consisted of 186 females and 76 males (N = 262) who predominately identified Caucasian/White (n = 149, 57.75%) and heterosexual/straight (n = 190, 73.64%) cultural identities with a mean age of 21.45 years (SD = 5.98, range = 18-65). A simultaneous logistic regression was conducted to examine whether mental health symptoms, sexual attitudes, and impulsivity predicted participants' decision to break SIP orders to engage in sexual intercourse. Based on our results, breaking SIP orders to pursue sexual activities with partners residing outside the home during the COVID-19 pandemic may be understood as an intentional strategy among men with less favorable birth control attitudes to mitigate the effects of depression. Implications for mental health professionals, study limitations, and future areas of research are additionally provided.

Touching a Mechanical Body: The Role of Anthropomorphic Framing in Physiological Arousal When Touching a Robot

The growing prevalence of social robots in various fields necessitates a deeper understanding of touch in Human-Robot Interaction (HRI). This study investigates how human-initiated touch influences physiological responses during interactions with robots, considering factors such as anthropomorphic framing of robot body parts and attributed gender. Two types of anthropomorphic framings are applied: the use of anatomical body part names and assignment of male or female gender to the robot. Higher physiological arousal was observed when touching less accessible body parts than when touching more accessible body parts in both conditions. Results also indicate that using anatomical names intensifies arousal compared to the control condition. Additionally, touching the male robot resulted in higher arousal in all participants, especially when anatomical body part names were used. This study contributes to the understanding of how anthropomorphic framing and gender impact physiological arousal in touch interactions with social robots, offering valuable insights for social robotics development.

Partner support and relationship quality as potential resources for childbirth and the transition to parenthood

BACKGROUND

The aim of the present paper was to explore the role of partners for the stressful life events of birth and the transition to parenthood.

METHODS

In a first prospective longitudinal study (N = 304 dyads) we tested whether relationship quality positively predicted fewer interventions during labor and birth, a more positive birth experience, and better well-being during the first six weeks after birth. In a second study we surveyed mothers (N = 980; retrospective quasi-experimental design) who had given birth during the first lockdown of the COVID-19 pandemic in spring 2020 - some in the absence of their partners - to test the assumption that regardless of relationship quality, the presence of the partner was positively related to low-intervention births and the birth experience.

RESULTS

The results of the longitudinal study (Study 1) could be integrated into a Single Indicator model. They revealed that a high relationship quality assessed between week 5 and week 25 of pregnancy had a positive effect on birth experience for the mother and on psychological well-being during the transition to parenthood for both mothers and fathers. Results of the retrospective quasi-experimental field study (Study 2) revealed that the continuous presence of the partner was associated with a higher probability of a low-intervention birth and a more positive birth experience. Presence of a partner for only part of the birth did not positively predict labor and birth, but did positively predict the birth experience. The effects were independent of relationship quality.

CONCLUSION

The results of both studies highlight the importance of partners for psychological well-being during labor and birth and the transition to parenthood.

Love and affectionate touch toward romantic partners all over the world

Touch is the primary way people communicate intimacy in romantic relationships, and affectionate touch behaviors such as stroking, hugging and kissing are universally observed in partnerships all over the world. Here, we explored the association of love and affectionate touch behaviors in romantic partnerships in two studies comprising 7880 participants. In the first study, we used a cross-cultural survey conducted in 37 countries to test whether love was universally associated with affectionate touch behaviors. In the second study, using a more fine-tuned touch behavior scale, we tested whether the frequency of affectionate touch behaviors was related to love in romantic partnerships. As hypothesized, love was significantly and positively associated with affectionate touch behaviors in both studies and this result was replicated regardless of the inclusion of potentially relevant factors as controls. Altogether, our data strongly suggest that affectionate touch is a relatively stable characteristic of human romantic relationships that is robustly and reliably related to the degree of reported love between partners.

Hugs and Cortisol Awakening Response the Next Day: An Ecological Momentary Assessment Study

Previous research suggests that affectionate touch such as hugs might downregulate stress systems such as the hypothalamic pituitary adrenal (HPA) axis. However, the current literature lacks in generalizability beyond the laboratory setting and outside the context of romantic relationships. The cortisol awakening response (CAR) is a measure of the HPA axis and is responsive to daily fluctuations in stress and social information. However, associations between affectionate touch and the CAR have never been assessed. This study used ecological momentary assessment (EMA) to measure daily hugging behaviors in 104 first-year college students and salivary cortisol to assess the CAR. Participants who reported more daily hugs in their social interactions had significantly smaller CARs the next morning compared to days they reported fewer hugs. This study contributes to the literature on social interactions and stress responsive systems and emphasizes the importance of assessing affectionate touch behaviors such as hugs that can be exchanged outside the context of romantic relationships.

Therapeutic touch and therapeutic alliance in pediatric care and neonatology: An active inference framework

Therapeutic affective touch has been recognized as essential for survival, nurturing supportive interpersonal interactions, accelerating recovery-including reducing hospitalisations, and promoting overall health and building robust therapeutic alliances. Through the lens of active inference, we present an integrative model, combining therapeutic touch and communication, to achieve biobehavioural synchrony. This model speaks to how the brain develops a generative model required for recovery, developing successful therapeutic alliances, and regulating allostasis within paediatric manual therapy. We apply active inference to explain the neurophysiological and behavioural mechanisms that underwrite the development and maintenance of synchronous relationships through touch. This paper foregrounds the crucial role of therapeutic touch in developing a solid therapeutic alliance, the clinical effectiveness of paediatric care, and triadic synchrony between health care practitioner, caregiver, and infant in a variety of clinical situations. We start by providing a brief overview of the significance and clinical role of touch in the development of social interactions in infants; facilitating a positive therapeutic alliance and restoring homeostasis through touch to allow a more efficient process of allostatic regulation. Moreover, we explain the role of CT tactile afferents in achieving positive clinical outcomes and updating prior beliefs. We then discuss how touch is implemented in treatment sessions to promote cooperative interactions in the clinic and facilitate theory of mind. This underwrites biobehavioural synchrony, epistemic trust, empathy, and the resolution of uncertainty. The ensuing framework is underpinned by a critical application of the active inference framework to the fields of pediatrics and neonatology.

"We've Got This": Middle-Aged and Older Couples' Satisfying Relationships and We-Talk Promote Better Physiological, Relational, and Emotional Responses to Conflict

OBJECTIVE

Conflict poses multiple relational and health risks. Dyadic stress theories suggest satisfaction and communication alter cardiovascular and autonomic function, key pathways from troubled relationships to poor health. However, "we-talk," a positive communication pattern, can strengthen relationships and promote health. We examined how each spouse's satisfaction and we-talk were related to conflict's physiological, relational, and emotional toll.

METHODS

Married couples ( n = 107 couples, 214 individuals, ages 40-87 years) who were mostly White, highly educated, and higher-income Americans in different-gender relationships engaged in 20-minute conflict discussions while wearing monitors to assess heart rate variability (HRV). Spouses rated their closeness immediately after conflict and their conflict rumination 2 hours later. Conflict transcriptions measured we-talk, or the proportion of first-person plural pronouns (we, us, our).

RESULTS

Satisfied spouses or those in mutually satisfying relationships had higher HRV during conflict ( b = 0.0001, p = .049), felt closer immediately after conflict ( b = 0.07, p < .001), and ruminated less about the conflict 2 hours later ( b = -0.26, p = .026). Spouses' HRV was highest ( b = 0.0002, p = .002) and rumination was lowest ( b = -0.49, p = .019) when they or their partners were satisfied and used we-talk more often. Women's HRV ( b = 0.0001, p = .035) and rumination ( b = -0.01, p = .02) benefited when both spouses were satisfied, as did closeness when women were satisfied ( b = 0.10, p < .001). Men's closeness benefited when they ( b = 0.04, p = .003) or their wives ( b = 0.04, p = .002) were satisfied.

CONCLUSIONS

The combination of mutually satisfying relationships and we-talk was associated with better relational and health outcomes after conflict. These findings are important for middle-aged and older couples whose relationships are central to their health.

The impact of WATSU as Physiotherapy Method on Fatigue for People Diagnosed with Multiple Sclerosis

Aim: To identify the impact of WATSU method on fatigue which has an impact on sleep and quality of life, pain and depression or its aggravation. Materials and Methods: The study involved the four participants. The following instruments were used: Multiple Sclerosis Quality of Life questionnaire; Pittsburgh Sleep Quality Index; Burns Depression Checklist; Fatigue Impact Scale. The study was carried out in medical center in Lithuania from 09-11-2019 till 18-01-2020 during 10 weeks. Each participant of the study received ten WATSU sessions. The research data was processed using SPSS Statistics 20. Qualitative Outcome Measures were conducted by content analysis, observation, semi-structured individual interview methods. Results: After 10 sessions, fatigue lessened in all people investigated. Initially, the average of fatigue was 70 points and decreased to 34 points after the investigation. The average sleep quality index was as high as 5 points, after ten weeks the average decreased to 3 points. Changes in assessment of major to mild depression: initially, the average was 36 points, which decreased to 14 points after ten weeks. Conclusions: The WATSU method was effective in reducing fatigue as a physiotherapy method. Along with changes in fatigue, the Pittsburgh Sleep Quality Index decreased, energy and motivation increased, quality of life improved, level of depression reduced, and the change was statistically significant. While assessing the quality of life, pain was found to be decreased – it became less frequent after ten weeks of sessions and less intense or even absent, its influence on daily activities decreased.

Attachment processes in posttraumatic stress disorder: A review of mechanisms to advance theories and treatments

Current conceptualisations of posttraumatic stress disorder (PTSD) are driven by biological, learning, and cognitive models that have shaped current treatments of the disorder. The strong influence of these models has resulted in a relative neglect of social mechanisms that can influence traumatic stress. There is abundant evidence from experimental, observational, and clinical studies that social factors can moderate many of the mechanisms articulated in prevailing models of PTSD. In this review it is proposed that attachment theory provides a useful framework to complement existing models of PTSD because it provides explanatory value for social factors can interact with biological, learning, and cognitive processes that shape traumatic stress response. The review provides an overview of attachment theory in the context of traumatic stress, outlines the evidence for how attachment factors can moderate stress responses and PTSD, and considers how harnessing attachment processes may augment recovery from and treatment of PTSD. This review emphasizes that rather than conceptualizing attachment theory as an independent theory of traumatic stress, there is much to gain by integrating attachment mechanisms into existing models of PTSD to accommodate the interactions between cognitive, biological, and attachment processes.

Advances in human oxytocin measurement: challenges and proposed solutions

Oxytocin, a neuropeptide known for its role in reproduction and socioemotional processes, may hold promise as a therapeutic agent in treating social impairments in patient populations. However, research has yet to uncover precisely how to manipulate this system for clinical benefit. Moreover, inconsistent use of standardized and validated oxytocin measurement methodologies-including the design and study of hormone secretion and biochemical assays-present unresolved challenges. Human studies measuring peripheral (i.e., in plasma, saliva, or urine) or central (i.e., in cerebrospinal fluid) oxytocin concentrations have involved very diverse methods, including the use of different assay techniques, further compounding this problem. In the present review, we describe the scientific value in measuring human endogenous oxytocin concentrations, common issues in biochemical analysis and study design that researchers face when doing so, and our recommendations for improving studies using valid and reliable methodologies.

Effects of intranasal oxytocin and positive couple interaction on immune factors in skin wounds

BACKGROUND

Intimate social relationships improve individual health and longevity, an effect which is supposed to be mediated through stress-sensitive endocrine and immune mechanisms in response to positive interaction behavior. On a neuroendocrine level, oxytocin (OT) buffers stress responses, modulates social attachment behavior and has been associated with cytokine expression. Consequently, the aim of the present study was to investigate instructed positive couple interaction, observed behavior, and OT in their effect on immune function.

METHODS

In a 4-group design, 80 healthy couples (N = 160 individuals) received four standard dermal suction blister wounds and were randomized to instructed positive interaction/control and intranasal OT/placebo. Unstimulated cytokines (IL-1β, IL-6, TNF-α) were assessed from wound liquid at 40 min, 105 min and 24 hrs after wounding.

RESULTS

Overall, group assignment did not affect friendly or dominant behavior during the interaction sequence. IL-1β and IL-6 levels, however, were moderated by group assignment with lowest levels in women in the positive interaction and OT condition in IL-1 and highest levels in IL-6. TNF-α responses to wounding were not affected from group assignment, however observed friendliness in women was associated with lower TNF-α levels.

DISCUSSION

These findings support the immune-regulating role of friendly behavior in romantic couples. Above this, the data provide the first empirical evidence that an intervention that simultaneously targets neuroendocrine mediators and behavior could affect immune function in a sex specific manner and with potential long-term health relevance.

The Associations Between Attitudes Toward Interpersonal Affective Touch, Negative Cognitions and Social Anxiety: A Pilot Study

Objective: Affectionate touch promotes psychological well-being likely through inducing cognitive and neurobiological changes, which implies the inverse association of affectionate touch to negative cognitive and psychosocial outcomes. Our aim was to explore relationships between attitudes toward interpersonal touch and social anxiety through fear of negative evaluation and self-critical rumination as mediating variables.Method: Data from 250 participants (69.6% females, n = 174) ranging in age from 18 to 65 years were collected through self-report inventories assessing attitudes toward physical touch from friends and family, nonromantic intimate person and unfamiliar person, fear of negative evaluation, self-critical rumination, and social anxiety. A moderated-mediation analysis was conducted. Results: No direct link was seen between attitudes toward friends and family touch experiences and social anxiety in both genders, but mediation through fear of negative evaluation was significant (p < .05). Attitudes toward nonromantic intimate touch were related to social anxiety only in females and only indirectly through self-critical rumination (p < .05). In both males and females, attitudes toward touch from unfamiliar persons were linked to social anxiety directly (p < .05) but indirect paths through fear of negative evaluation (p < .05) and self-critical rumination were seen only in females (p < .05). Conclusions: Findings indicate that attitudes toward interpersonal affectionate touch may be predictive of social anxiety and the negative cognitions associated with it, extending previous findings on social pain and attesting to the potential clinical utility of touch-based interventions for social anxiety.

Transcranial direct current stimulation of the right anterior temporal lobe changes interpersonal neural synchronization and shared mental processes

BACKGROUND

Previous studies have shown that interpersonal neural synchronization (INS) is a ubiquitous phenomenon between individuals, and recent studies have further demonstrated close associations between INS and shared external sensorimotor input and/or internal mental processes within a dyad. However, most previous studies have employed an observational approach to describe the behavior-INS correlation, leading to difficulties in causally disentangling the relationship among INS, external sensorimotor input and the internal mental process.

OBJECTIVE/HYPOTHESIS

The present study aimed to directly change the level of INS through anodal transcranial direct current stimulation (tDCS) to test whether the change in INS would directly impact the internal mental process (Hypothesis 1) or indirectly through external sensorimotor input; the interaction behaviors were also changed (Hypothesis 2) or not (Hypothesis 3).

METHODS

Thirty pairs of romantically involved heterosexual couples were recruited for a within-subjects design. Three conditions were assessed: a true stimulation condition with 20-min anodal high-definition tDCS to the right anterior temporal lobe (rATL) of women before they communicated with their partners, a sham stimulation condition and a control brain region stimulation condition. The comparison between the true and sham or control brain region conditions allows us to detect the true effect of brain stimulation on INS. Functional near-infrared spectroscopy (fNIRS) hyperscanning was used to simultaneously collect dyadic participants' hemodynamic signals during communication. INS, empathy, and interaction behaviors were examined and compared among different stimulation conditions.

RESULTS

True brain stimulation significantly decreased INS between the rATL of the women and sensorimotor cortex (SMC) of the men compared to the sham stimulation condition (t(27.8) = -2.821, P = 0.009, d = 0.714) and control brain region stimulation condition (t(27.2) = -2.606, P = 0.015, d = 0.664) during communication. It also significantly decreased the level of emotional empathy (F(2,145) = 6.893, P = 0.001) but did not change sensorimotor processes, such as verbal or nonverbal interaction behaviors. However, nonverbal behaviors mediated the relationship between the changes in INS and emotional empathy (lower limit confidence interval = 0.01, upper limit confidence interval = 2.66).

CONCLUSION(S)

These findings support the third hypothesis, suggesting that INS is associated with the shared internal mental process indirectly via the sensorimotor process, but the sensorimotor process itself does not covary with the INS and the associated internal mental process. These results provide new insight into the hierarchical architecture of dual-brain function from a bottom-up perspective.

Examining how different social account timings influence stress resolution in the aftermath of a psychological contract breach

A great deal of empirical research on the consequences of a psychological contract breach (PCB) has overlooked the role of time in understanding individuals' reactions to a PCB. Moreover, psychological contract research primarily focuses on how employees react to perceptions of a PCB, while questions regarding how the organization's responsiveness (i.e., social account) might impact these reactions remain unanswered. We aimed to enhance the understanding of stress reactions and recovery that are triggered by PCB perceptions and stimulate empirical research that treats psychological contracts as a dynamic phenomenon. Drawing on the conservation of resources theory, we investigated how social account delivery timing-and its subjective experience-influences individuals' stress resolution processes in the aftermath of a PCB. To this end, we used an experimental design and assessed participants' physiological (i.e., heart rate) and psychological (i.e., self-report) stress reactions after inducing a breach. Our results underscore that a PCB is experienced as a stressful event. In addition, we find that social account timing influences heart rate recovery following a PCB. We discuss the theoretical and practical implications of our findings and offer recommendations for practitioners.

Stressor anticipation and subsequent affective well-being: A link potentially explained by perseverative cognitions

Anticipatory stress can prospectively and negatively influence diverse outcomes, including cognitive performance and emotional well-being. It has been suggested that perseverative cognitions (e.g., worry, rumination) during the anticipation period constitute a key mechanism driving these effects. The present study investigated the temporal dynamics among stressor anticipation, perseverative cognitions, and affective well-being. To accurately test the suggested mechanism, we focused on how these dynamics unfold within individuals over time. To that end, we analyzed data from an ecological momentary assessment study in an ethnically diverse sample (N = 243, 25-65 year olds, 68.7% Hispanic or non-Hispanic Black; 14 days, 5 measurement occasions per day) using dynamic structural equation modeling. Anticipating an upcoming stressor was linked to higher levels of perseverative cognitions approximately 3 hours later. At times when individuals reported higher levels of recent perseverative cognitions than typical for them, they also reported higher levels of negative affect and lower levels of positive affect. Mediational modeling indicated that perseverative cognitions accounted for the persistent effects of previous stressor anticipation on negative as well as positive affect several hours later. These findings suggest that perseverative cognitions may play an important role in explaining the detrimental effects of anticipatory stress on subsequent emotional well-being. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The brain-body disconnect: A somatic sensory basis for trauma-related disorders

Although the manifestation of trauma in the body is a phenomenon well-endorsed by clinicians and traumatized individuals, the neurobiological underpinnings of this manifestation remain unclear. The notion of somatic sensory processing, which encompasses vestibular and somatosensory processing and relates to the sensory systems concerned with how the physical body exists in and relates to physical space, is introduced as a major contributor to overall regulatory, social-emotional, and self-referential functioning. From a phylogenetically and ontogenetically informed perspective, trauma-related symptomology is conceptualized to be grounded in brainstem-level somatic sensory processing dysfunction and its cascading influences on physiological arousal modulation, affect regulation, and higher-order capacities. Lastly, we introduce a novel hierarchical model bridging somatic sensory processes with limbic and neocortical mechanisms regulating an individual's emotional experience and sense of a relational, agentive self. This model provides a working framework for the neurobiologically informed assessment and treatment of trauma-related conditions from a somatic sensory processing perspective.

Feeling low and unhappy together? An actor-partner-interdependence model uncovering the linkage between different operationalizations of relationship quality and depression in different-sex couples

Some studies suggest a bi-directional association between low relationship quality and depression. However, the social impact of depression and the potential preventative effects of healthy relationships are not yet sufficiently understood, as studies have shown heterogenous results for effects in both directions. Therefore, the main aim of this study was to differentiate the actor and partner effects of this association more comprehensively using two measures to capture characteristics of relationship quality–firstly regarding general aspects of social system quality and secondly considering specific aspects of the romantic relationship. 110 different-sex couples were included, being separated in partners with highly pronounced depressive symptoms in women (Cw/DW) versus partners with low depressive symptoms (LDCs). We investigated effects cross-sectionally using multi-group analyses to predict relationship (couple specific questionnaire: PFB) versus system quality (general system quality questionnaire: EVOS) in a step-by-step approach, modelling actor and partner effects with variation within and across both groups and then comparing the results to models with equal actor and partner effects. Depression was measured with the PHQ-9. With regard to the relationship between depressive symptoms and system quality, the model that constrained actor and partner effects to be equal across both groups was preferred and showed negative significant actor effects across gender and groups. Concerning the association between depressive symptoms and relationship quality, the model constraining actor and partner effects to be equal within groups had the best fit to the data and revealed a negative partner effect in LDCs.

Conclusions

Controlling for the moderating variable of clinically relevant depressive symptoms, we found evidence for actor and partner effects, which differed between the two relationship measures. This underlines the importance to reflect how relationship quality is operationalized. The negative partner effect on relationship quality in LDCs emphasizes that even in a non-clinical context, depressive symptoms negatively impact the perceived relationship quality of both women and men. This suggests that addressing the relationship is important in non-clinical preventive contexts and calls for integrating the partner into counselling or trainings.

Affective Touch and Regulation of Stress Responses

Much has been documented on the association between stress and health. Both direct and indirect pathways have been identified and explored extensively, helping us understand trajectories from healthy individuals to reductions in well-being, and development of preclinical and disease states. Some of these pathways are well established within the field; physiology, affect regulation, and social relationships. The purpose of this review is to push beyond what is known separately about these pathways and provide a means to integrate them using one common mechanism. We propose that social touch, specifically affective touch, may be the missing active ingredient fundamental to our understanding of how close relationships contribute to stress and health. We provide empirical evidence detailing how affective touch is fundamental to the development of our stress systems, critical to the development of attachment bonds and subsequent social relationships across the life course. We will also explore how we can use this in applied contexts and incorporate it into existing interventions.

Intimate Pride: a Tri-Nation Study on Associations between Positive Minority Identity Aspects and Relationship Quality in Sexual Minorities from German-Speaking Countries

Investigations into the intimate relationships of sexual minorities are proliferating, but often adopt a deficit-oriented and US-centered perspective. In this tri-nation online study with sexual minority participants from Austria, Germany, and Switzerland (N = 571), we (i) assessed the construct validity of the German version of a well-known measure for positive minority identity aspects (the Lesbian, Gay, Bisexual Positive Identity Measure; LGB-PIM), and (ii) explored associations between these aspects (self-awareness, authenticity, community, capacity for intimacy, and social justice) and self-reported relationship quality. Model fit of the German version of the LGB-PIM was deemed acceptable. Higher levels of positive minority identity aspects showed small to moderate associations with higher levels of relationship quality in bivariate analyses, but only capacity for intimacy was linked to relationship quality in higher-order models (controlling for country, age, sexual orientation, gender identity, relationship length, and psychological distress). Results remained robust in several sensitivity analyses. Our results highlight the differential role of positive identity aspects for relationship functioning, with capacity for intimacy as a fruitful leverage point for therapeutic work.

Decreased self-reported receiving of social touch and social support predict loneliness in healthy adults

Loneliness has emerged as a public health concern. Previous research has reported its deleterious effects on physical and mental health; however, some specific psychophysiological mechanisms in healthy adults remain to be elucidated. The aim of the current study is to investigate whether self-reported social support and social touch (giving and receiving social touch), as well as resting heart rate variability (HRV), are significant negative predictors of loneliness in healthy adults. The study sample consists of 120 healthy students (50% female) with a mean age of 21.85 years old (DP= 2.21). The students were asked to complete a psychiatric screening questionnaire utilizing loneliness, social support, and social touch scales. HRV was derived from an electrocardiographic signal recorded for 15 min, with the participant relaxed in a supine position. Linear regression analyses were conducted to evaluate loneliness as a function of social support, social touch (giving or receiving touch), and resting HRV. The results show that social support (p< 0.001) and social touch, specifically receiving touch (p< 0.002), accounted for a significant proportion of the variance in loneliness. However, neither giving touch nor resting HRV was a significant predictor of loneliness. The current study highlights specific psychosocial factors in healthy adults that should be considered as promising pathways in order to reduce or work toward preventing loneliness, thus promoting better health and well-being.

Interaction Matters: The Effect of Touching the Social Robot PARO on Pain and Stress is Stronger When Turned ON vs. OFF

Social touch between humans, as well as between humans and animals, was previously found to reduce pain and stress. We previously reported that touching a social robot can also induce a reduction in pain ratings. However, it is unclear if the effect that touching a robot has on pain perception is due to its appearance and its pleasant touch, or due to its ability to socially interact with humans. In the current experiment, we aimed to assess the contribution of the interactive quality to pain perception. We assessed the effect of touching the social robot PARO on mild and strong pain ratings and on stress perception, on a total of 60 healthy young participants. The robot either interacted with participants (ON group, n = 30) or was turned off (OFF group, n = 30). Touching the robot induced a decrease in mild pain ratings (compared to baseline) only in the ON group while strong pain ratings decreased similarly in both the ON and the OFF groups. The decrease in mild pain ratings in the ON group was significantly greater in participants with a higher positive perception of the interaction with PARO. We conclude that part of the effect that touching the robot has on pain stems from its interactive features.

Therapeutic Alliance as Active Inference: The Role of Therapeutic Touch and Biobehavioural Synchrony in Musculoskeletal Care

Touch is recognised as crucial for survival, fostering cooperative communication, accelerating recovery, reducing hospital stays, and promoting overall wellness and the therapeutic alliance. In this hypothesis and theory paper, we present an entwined model that combines touch for alignment and active inference to explain how the brain develops "priors" necessary for the health care provider to engage with the patient effectively. We appeal to active inference to explain the empirically integrative neurophysiological and behavioural mechanisms that underwrite synchronous relationships through touch. Specifically, we offer a formal framework for understanding - and explaining - the role of therapeutic touch and hands-on care in developing a therapeutic alliance and synchrony between health care providers and their patients in musculoskeletal care. We first review the crucial importance of therapeutic touch and its clinical role in facilitating the formation of a solid therapeutic alliance and in regulating allostasis. We then consider how touch is used clinically - to promote cooperative communication, demonstrate empathy, overcome uncertainty, and infer the mental states of others - through the lens of active inference. We conclude that touch plays a crucial role in achieving successful clinical outcomes and adapting previous priors to create intertwined beliefs. The ensuing framework may help healthcare providers in the field of musculoskeletal care to use hands-on care to strengthen the therapeutic alliance, minimise prediction errors (a.k.a., free energy), and thereby promote recovery from physical and psychological impairments.

Examining the impact of social stressor stimuli in eliciting physiological reactivity in children and adolescents with autism spectrum disorder: a systematic review and meta-analysis protocol

INTRODUCTION

Stress is not experienced the same by everyone. Some individuals, such as individuals with autism spectrum disorder (ASD), are at risk of heightened sensitivity to stress responses. ASD is a neurodevelopmental disorder commonly characterised by deficits in social communication and social interaction. Among different stressor stimuli, social stressors are particularly worth our attention due to the social and communication challenges inherent in ASD. This study aims to systematically evaluate different social stressor stimuli in eliciting physiological reactivity in ASD, focusing on the children and adolescent population.

METHODS AND ANALYSIS

We designed a study protocol for this study and submitted it to PROSPERO for systematic review registration. Any studies with children and adolescents with ASD between the ages of 0 and 18 in clinical and community settings will be included. All types of social stressor interventions will be included. The outcome of interest will include studies with physiological activity of the participants being measured, for example, measures related to autonomic functioning, electrodermal functioning and cortisol level. The primary literature sources will be across four electronic databases: MEDLINE, Embase, PsycInfo and CINAHL in August 2021. The second source of literature will be across grey literature, including ProQuest Dissertations & Theses Global and across clinical trial registries in August 2021. Hand searching of references will be performed on the reference lists of all included studies. Two volunteers pursuing postgraduate-level studies will independently search and screen potential studies for eligibility. Finally, all references considered by hand searching will be reviewed by two researchers. The methodological quality of the research will be assessed by adopting the quality assessment used by a previous study. The assessment consists of four primary categories: descriptive validity, internal validity, external validity and statistical conclusion validity.

ETHICS AND DISSEMINATION

No ethical approval is required for this study. Results will be disseminated through conferences and publications in relevant peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42021244039.

Affective Experience and Regulation via Sleep, Touch, and "Sleep-Touch" Among Couples

Touch associated with sleep (sleep-touch; reported physical contact during or shortly before/after sleep) is underexplored as a distinct contributor to affect regulatory processes associated with adult sleep. Given the affect-regulating effects of interpersonal touch, we theorized that among healthy co-sleeping adults, sleep-touch would add to sleep-related effects on affective "resetting," resulting in the experience of calmer, more regulated states. We studied 210 married heterosexual couples (aged 20-67 years, 79% non-Hispanic white, 13% Latinx) assigned 14 days of twice-daily (morning/evening) sleep/mood diaries. Multilevel daily (within-couple) mediation analyses showed that as hypothesized, more reported sleep-touch was associated with happier/calmer and less angry/irritable morning mood. In turn, happier/calmer mood was associated with greater enjoyment of time with spouse (for both spouses). Sleep-touch also was linked directly to both evening positive spousal events and enjoyment ratings. Sleep-touch was associated indirectly with fewer negative spousal events and less spouse-related stress via less angry/irritable morning mood (both spouses). Further, wives' sleep-touch was related to happier/calmer husband mood and evening enjoyment; husbands' sleep-touch was unrelated to wives' reports. All associations with sleep-touch were present while accounting for subjective sleep quality, prior evening mood, non-sleep-related physical affection, day in study, and weekend versus weekday. We speculate that among relatively healthy satisfied couples, physical touch during and surrounding sleep may add to sleep's restorative and affect-regulatory functions, suggesting a pathway through which co-sleeping can improve affect regulation and ultimately relationships and health.

Understanding sex differences in affective touch: Sensory pleasantness, social comfort, and precursive experiences

Although previous research revealed sex differences in affective touch, the implicated processes and the manner in which men and women differ have been left uncertain. Here we addressed this issue in two studies examining sensory pleasure, interpersonal comfort, and touch motivators. Study 1 comprised a series of lab-based experiments in which a robot stroked 214 participants (half female) at five different velocities modulating the activity of C-tactile afferents thought to support tactile pleasantness. Average pleasantness ratings followed velocity with the typical inverted u-shape similarly in both sexes. In Study 2, 260 participants (half female) completed an online survey. Here, women were more likely than men to express touch comfort with less familiar or unknown individuals, had a greater preference for touch with other women, and felt more comfortable giving and receiving touch to the forearm. Additionally, when describing how their own experiences might motivate others to touch them affectively, women produced more negative descriptions than men. Together, these results show that, while the sexes compare in a touch's sensory pleasantness, they differ in their preceding affective experiences and how they value touch at a higher-order social level. This agrees with extant research on negative affect and stress and suggests that affective touch may be a more relevant coping mechanism for women than for men.

Salivary Cortisol, but Not Oxytocin, Varies With Social Challenges in Domestic Pigs: Implications for Measuring Emotions

Animals respond to inherently rewarding or punishing stimuli with changes in core affective states, which can be investigated with the aid of appropriate biomarkers. In this study we evaluate salivary cortisol (sCORT) and salivary oxytocin (sOXT) concentrations under baseline conditions and in response to two negatively- and two positively-valenced social challenges in 75 young pigs (Sus scrofa domesticus), housed and tested in eight social groups. We predicted that: (1) Relative to baseline, weaning and brief social isolation would be associated with increases in sCORT, due to psychosocial stress, and reductions in sOXT, due to a lack of opportunities for social support; and (2) Opportunities for social play, and reunions with group members after a separation would be associated with weaker sCORT responses, and increases in sOXT concentrations compared to baseline and to negative social challenges. Testing and sample collection occurred between 28 and 65 days of age and involved a within-subject design, in which every subject was sampled multiple times in neutral (baseline), negative and positive social contexts. We also recorded behavioral data and measured rates of agonism, play and affiliative interactions in the different contexts, prior to saliva sampling. As expected, negative social challenges were associated with robust cortisol responses. Relative to baseline, pigs also had higher sCORT responses to positive social challenges, although these differences were only significant during reunions. Salivary oxytocin concentrations did not differ between the different social conditions, although sOXT was lowest during the brief social isolation. Behavioral analyses confirmed predictions about the expected changes in social interactions in different social contexts, with increases in agonism following weaning, increases in coordinated locomotor play in the play context and high rates of affiliative interactions during reunions. Relative sCORT reactivity to different contexts may reflect the intensity of emotional responses, with greater increases occurring in response to challenges that involve more psychosocial stress. Our results suggest that sOXT is not a reliable indicator of emotional valence in pigs, although more research is needed to characterize sOXT responses to various challenges with and without access to social support.

Romantic partner embraces reduce cortisol release after acute stress induction in women but not in men

Stress is omnipresent in our everyday lives. It is therefore critical to identify potential stress-buffering behaviors that can help to prevent the negative effects of acute stress in daily life. Massages, a form of social touch, are an effective buffer against both the endocrinological and sympathetic stress response in women. However, for other forms of social touch, potential stress-buffering effects have not been investigated in detail. Furthermore, the possible stress-buffering effects of social touch on men have not been researched so far. The present study focused on embracing, one of the most common forms of social touch across many cultures. We used a short-term embrace between romantic partners as a social touch intervention prior to the induction of acute stress via the Socially Evaluated Cold Pressor Test. Women who embraced their partner prior to being stressed showed a reduced cortisol response compared to a control group in which no embrace occurred. No stress-buffering effect could be observed in men. No differences between the embrace and control group were observed regarding sympathetic nervous system activation measured via blood pressure or subjective affect ratings. These findings suggest that in women, short-term embraces prior to stressful social situations such as examinations or stressful interviews can reduce the cortisol response in that situation.

Social Support as a Stress Buffer or Stress Amplifier and the Moderating Role of Implicit Motives: Protocol for a Randomized Study (Preprint)

Background

Previous research shows that providing social support in socioevaluative stress situations reduces participants’ stress responses. This stress-buffer effect, however, does not hold for everybody, and some studies even found a stress-amplifying effect of social support. Motive disposition research suggests that social motives (affiliation and power) lead to differential and sometimes even opposing affective and physiological responses to interpersonal interaction processes. We here integrate both lines of research and hypothesize that participants with strong affiliation motives benefit, while participants with strong power motives do not benefit from social support in terms of psychobiological responses to a given stressor. Further, participants with strong affiliation and power motives are expected to respond to social support with the arousal of motive-specific affects and reproductive hormone responses (affiliation: progesterone; power: estradiol and testosterone). In addition, we test sex differences in the response to social support and in the strengths of social motives.

Objective

The main objective of this study is to test whether social motives and participants’ sex moderate the effects of social support in stressful situations.

Methods

We aim to collect data from 308 participants recruited at our local university. Participants’ social motives are assessed using a standardized measure in motive research (Picture Story Exercise). Then, the Trier Social Stress Test for Groups (TSST-G) is used to experimentally induce psychosocial stress. One group of participants receives social support from an associate of the experimenter, while the control group does not receive social support. Stress responses will be assessed by a modified version of the state anxiety scale of the State–Trait Anxiety Inventory and by physiological indicators of stress (cortisol and α-amylase from saliva samples) at 7 measurement points. Reproductive hormones will be analyzed in 4 of these 7 saliva samples. Heart rate and heart rate variability will be assessed continuously. We will additionally measure participants’ performance in an interview (part of the TSST-G) using a self-developed categorization system.

Results

The Ethics Committee of the University of Constance approved the application to conduct the study on December 18, 2018. Furthermore, the study was retrospectively registered in the German Clinical Trials Register (DKRS; ID: DRKS00028503) on March 09, 2022. The start of the experiment was planned for the beginning of 2019, but was postponed to June 2021 due to COVID-19. Publication of the first results is planned for spring 2023.

Conclusions

Our theory-driven integration of social motives in social support research and the precise analysis of sex differences might disentangle inconsistent findings in TSST research. The more faceted view on individual differences has direct implications for applied contexts as it provides a framework for tailored conceptualizations of social support programs.

Trial Registration

German Clinical Trials Register DRKS00028503; https://tinyurl.com/5a87x4da

International Registered Report Identifier (IRRID)

PRR1-10.2196/39509

An Interaction Theory Account of (Mediated) Social Touch

Research on mediated social touch (MST) has, either implicitly or explicitly, built on theoretical assumptions regarding social interactions that align with "theory theory" or "simulation theory" of social cognition. However, these approaches struggle to explain MST interactions that occur outside of a laboratory setting. I briefly discuss these approaches and will argue in favor of an alternative, "interaction theory" approach to the study of MST. I make three suggestions for future research to focus on.

C-low threshold mechanoafferent targeted dynamic touch modulates stress resilience in rats exposed to chronic mild stress

Affiliative tactile interactions buffer social mammals against neurobiological and behavioral effects of stress. The aim of this study was to investigate the cutaneous mechanisms underlying such beneficial consequences of touch by determining whether daily stroking, specifically targeted to activate a velocity/force tuned class of low-threshold c-fiber mechanoreceptor (CLTM), confers resilience against established markers of chronic unpredictable mild stress (CMS). Adult male Sprague Dawley rats were exposed to 2 weeks of CMS. Throughout the CMS protocol, some rats were stroked daily, either at CLTM optimal velocity (5 cm/s) or outside the CLTM optimal range (30 cm/s). A third CMS exposed group did not receive any tactile stimulation. The effect of CMS on serum corticosterone levels, anxiety- and depressive-like behaviors in these three groups was assessed in comparison to a control group of non-CMS exposed rats. While stroking did not mitigate the effects of CMS on body weight gain, CLTM optimal velocity stroking did significantly reduce CMS-induced elevations in corticosterone following an acute forced-swim. Rats receiving CLTM optimal stroking also showed significantly fewer anxiety-like behaviors (elevated plus-maze) than the other CMS exposed rats. In terms of depressive-like behavior, whereas the same velocity-specific resilience was observed in a forced-swim test and social interaction test both groups of stroked rats spent significantly less time interacting than control rats, though they also spent significantly less time in the corner than non-stroked CMS rats. Together, these findings support the theory CLTMs play a functional role in regulating the physiological condition of the body.

In the Arms of a Robot: Designing Autonomous Hugging Robots with Intra-Hug Gestures

Hugs are complex affective interactions that often include gestures like squeezes. We present six new guidelines for designing interactive hugging robots, which we validate through two studies with our custom robot. To achieve autonomy, we investigated robot responses to four human intra-hug gestures: holding, rubbing, patting, and squeezing. Thirty-two users each exchanged and rated sixteen hugs with an experimenter-controlled HuggieBot 2.0. The robot’s inflated torso’s microphone and pressure sensor collected data of the subjects’ demonstrations that were used to develop a perceptual algorithm that classifies user actions with 88% accuracy. Users enjoyed robot squeezes, regardless of their performed action, they valued variety in the robot response, and they appreciated robot-initiated intra-hug gestures. From average user ratings, we created a probabilistic behavior algorithm that chooses robot responses in real time. We implemented improvements to the robot platform to create HuggieBot 3.0 and then validated its gesture perception system and behavior algorithm with sixteen users. The robot’s responses and proactive gestures were greatly enjoyed. Users found the robot more natural, enjoyable, and intelligent in the last phase of the experiment than in the first. After the study, they felt more understood by the robot and thought robots were nicer to hug.

Physical Intimacy in Older Couples' Everyday Lives: Its Frequency and Links with Affect and Salivary Cortisol

OBJECTIVES

Physical intimacy is important for communicating affection in romantic relationships. Theoretical and empirical work highlights linkages between physical intimacy, affect, and physiological stress among young and middle-aged adults, but not older adults. We examine physical intimacy and its associations with positive and negative affect and cortisol levels in the daily lives of older couples.

METHOD

We applied actor-partner multilevel models to repeated daily life assessments of physical intimacy (experienced and wished) and affect obtained six times a day over seven consecutive days from 120 older heterosexual German couples (Mage= 71.6, SDage= 5.94). Physiological stress was indexed as total daily cortisol output, the area under the curve with respect to ground (AUCg).

RESULTS

Physical intimacy experienced and wished were reported at the vast majority of occasions, but to different degrees at different times. Within persons, in moments when participants experienced more physical intimacy, older women reported less negative affect, whereas older men reported more positive affect. Between persons, higher overall levels of physical intimacy experienced were associated with higher positive affect and less negative affect among women and with lower daily cortisol output among men. A stronger wish for intimacy was related to more negative affect among both women and men, and to higher daily cortisol output among men.

DISCUSSION

Physical intimacy is linked with mood and stress hormones in the daily life of older couples. We consider routes for future inquiry on physical intimacy among older adults.

Personality and Alcohol Use across College: Examining Context-Dependent Pathways toward Alcohol Problems

BACKGROUND

College life is characterized by marked increases in alcohol consumption. Extraversion and neuroticism are associated with alcohol use problems in college and throughout adulthood, each with alcohol use patterns consistent with an externalizing and internalizing pathway respectively. Students higher in extraversion drink more frequently and consume more alcohol, while neuroticism is paradoxically not consistently associated with elevated alcohol use.

OBJECTIVE

This study examined whether students higher in neuroticism may drink the day before stressors, namely tests and assignment deadlines.

METHOD

Multilevel generalized linear models were performed using data from a longitudinal study of first-time, first-year undergraduates assessing alcohol use across four years of college, with daily diary bursts each semester.

RESULTS

Students higher in extraversion had heavier alcohol use and greater alcohol use problems in their fourth year of college. Neuroticism was not associated with drinking behaviors or with drinking before a test or assignment, but was associated with greater fourth year alcohol problems. Students lower in extraversion who reduced heavy drinking the day before academic events had fewer alcohol use problems at the fourth year of college relative to students higher in extraversion.

CONCLUSIONS

Students higher in extraversion appear to exhibit a continuity of established alcohol use patterns from adolescence, predisposing them to a more hazardous trajectory of college alcohol use. Characteristics of low extraversion may afford some protection from alcohol-positive college culture. High neuroticism appears associated with a hazardous trajectory of college alcohol use, but continued research into situational factors of alcohol use in high neuroticism is warranted.

A public context with higher minority stress for LGBTQ* couples decreases the enjoyment of public displays of affection

This research investigated whether LGBTQ* minority stress and public displays of affection (PDA; e.g., kissing, hugging) among LGBTQ* couples are context-sensitive. We expected that (a) LQBTQ* minority stress would be more prevalent in a harmful (i.e., city center) versus a less harmful (i.e., university campus) context, and (b) PDA would be reduced for LGBTQ* couples in a harmful context. In three studies, LGBTQ* and Hetero/Cis students (N_Total = 517) reported LGBTQ*-specific minority stress and PDA in the city and on campus. The city center was higher in minority stress than the campus in all studies. Also, LGBTQ* participants’ PDA enjoyment was lower in the city than on campus (Studies 1 and 3). Minority stress mediated the context effect on PDA (Study 3). A qualitative analysis illuminated the harmful versus protective natures of public contexts. We conclude that a protective context can powerfully promote healthy LGBTQ* relationship behavior.

Tactile Interaction with a Humanoid Robot: Effects on Physiology and Subjective Impressions

This study investigated how touching and being touched by a humanoid robot affects human physiology, impressions of the interaction, and attitudes towards humanoid robots. 21 healthy adult participants completed a 3 (touch style: touching, being touched, pointing) × 2 (body part: hand vs buttock) within-subject design using a Pepper robot. Skin conductance response (SCR) was measured during each interaction. Perceived impressions of the interaction (i.e., friendliness, comfort, arousal) were measured per questionnaire after each interaction. Participants’ demographics and their attitude towards robots were also considered. We found shorter SCR rise times in the being touched compared to the touching condition, possibly reflecting psychological alertness to the unpredictability of robot-initiated contacts. The hand condition had shorter rise times than the buttock condition. Most participants evaluated the hand condition as most friendly and comfortable and the robot-initiated interactions as most arousing. Interacting with Pepper improved attitudes towards robots. Our findings require future studies with larger samples and improved procedures. They have implications for robot design in all domains involving tactile interactions, such as caring and intimacy.

Discussions and perspectives regarding oxytocin as a biomarker in human investigations

This article introduces a review of research that has implemented oxytocin measurements in different fluids such as plasma, cerebrospinal fluid, urine and, mainly, saliva. The main purpose is to evaluate the level of evidence supporting the measurement of this biomarker implicated in a variety of psychological and social processes. First, a review of the technical developments that allowed the characterization, function establishing, and central and peripheral levels of this hormone is proposed. Then, the article approaches the current discussions regarding the level of reliability of the laboratory techniques that enable the measurement of oxytocin, focusing mainly on the determination of its concentration in saliva through Enzyme-Linked Immunosorbent Assay (ELISA). Finally, research results, which have established the major physiological correlates of this hormone in fields such as social neuroscience and neuropsychology, are collected and discussed in terms of the hormone measurement methods that different authors have used. In this way, the article is expected to contribute to the panorama of debates and current perspectives regarding investigation involving this important biomarker.

Self-soothing touch and being hugged reduce cortisol responses to stress: A randomized controlled trial on stress, physical touch, and social identity

Background

Being touched by others improves stress coping. However, when touch from others is unavailable, feels uncomfortable, or is not considered to be safe (as in the COVID-19 pandemic), self-touch gestures, like placing a hand on the heart, may provide an alternative way to experience less strain.

Methods and materials

In this study, 159 healthy participants (96 women, 62 men, and 1 non-binary person), aged 18–35 years, were exposed to a standardized psychosocial stressor (Trier Social Stress Test) to investigate whether self-soothing touch or receiving a hug from others has a buffering effect on their stress responses. In addition, the study explored whether the effectiveness of these interventions is moderated by participants' assignment to a “personal” or “social” identity condition. Participants provided salivary cortisol samples, wore an ECG to record their heart rate, and completed self-report measures on stress-related subjective-emotional states during the study.

Results

For cortisol, mixed-effects regression models with Touch and Identity as between-subject factors and Time as the within-subject factor yielded a significant main effect for touch and a significant interaction of Touch x Time indicating that cortisol levels differed between the experimental touch interventions. Post-hoc contrast tests showed that participants in both touch conditions had lower cortisol levels after the stressor than those in the control conditions. Heart rates and self-reported measures of stress neither differed across touch nor identity conditions. The three-way interaction for Touch x Identity x Time was non-significant for either outcome measure.

Discussion

These results are in line with previous work indicating that physical touch has protective effects on physiological stress responses but not necessarily on self-reported stress and suggest that self-soothing touch and receiving hugs are simple and yet potentially powerful means for buffering individuals' resilience against stress.

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Self-soothing touch gestures reduce cortisol responses to psychosocial stress.

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Receiving hugs also reduces cortisol responses to psychosocial stress.

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Benefits from receiving hugs are independent of social identification.

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Self-soothing touch might reduce stress-responses in times of limited social resources.

Manifesto for Digital Social Touch in Crisis

This qualitative exploratory research paper presents a Manifesto for Digital Social Touch in Crisis - a provocative call to action to designers, developers and researchers to rethink and reimagine social touch through a deeper engagement with the social and sensory aspects of touch. This call is motivated by concerns that social touch is in a crisis signaled by a decline in social touch over the past 2 decades, the problematics of inappropriate social touch, and the well documented impact of a lack of social touch on communication, relationships, and well-being and health. These concerns shape how social touch enters the digital realm and raise questions for how and when the complex space of social touch is mediated by technologies, as well the societal implications. The paper situates the manifesto in the key challenges facing haptic designers and developers identified through a series of interdisciplinary collaborative workshops with participants from computer science, design, engineering, HCI and social science from both within industry and academia, and the research literature on haptics. The features and purpose of the manifesto form are described, along with our rationale for its use, and the method of the manifesto development. The starting points, opportunities and challenges, dominant themes and tensions that shaped the manifesto statements are then elaborated on. The paper shows the potential of the manifesto form to bridge between HCI, computer science and engineers, and social scientists on the topic of social touch.