Cardiac vagal tone: a neurophysiological mechanism that evolved in mammals to dampen threat reactions and promote sociality

When the body fosters empathy: The interconnectivity between bodily reactivity, meditation, and embodied abstract concepts

Empathy is a fundamental social ability that allows humans to infer others' emotions and intentions. Empathy is thought to be rooted in bodily sensations coming from the autonomic nervous system. In parallel, the functionality and perceptions coming from the autonomic nervous system could be improved by practicing activities that involve mind-body interactions, such as meditation. Furthermore, perceptions from the autonomic nervous system are thought to be important in the embodiment of abstract concepts. Consequently, in the current study, we collected data online from 581 participants and explored the associations between levels of empathy and (1) the practice of meditation, music, and sports; (2) the impact of self-report measures on bodily awareness and reactivity; and (3) the embodiment of abstract concepts in interoception. In line with previous studies, Meditators were found to have higher empathy scores than Non-Meditators. In addition, lower levels of autonomic reactivity in organs above the diaphragm were associated with higher empathy. Finally, we also observed that empathy was positively associated with interoceptive components of abstract concepts in those participants with high autonomic reactivity. Taken together, the results suggest that meditation practice and having low autonomic reactivity are associated with empathy, arguably through the downregulation of autonomic responses. Implications for mind-body interaction in meditation and its role in promoting empathy are discussed.

Interactive synchrony and infants' vagal tone as an index of emotion regulation: associations within each mother- and father-infant dyad and across dyads

Introduction

Studies have shown that infants' emotion regulation capacities are closely linked to the quality of parent-infant interactions. However, these links have been mostly studied in mother-infant dyads and less is known about how the quality of father-infant interactions contributes to the development of emotion regulation during infancy. In this study, we aimed to investigate the links between interactive synchrony (i.e., an index of the quality of parent-infant coordination of interactive behaviors) and infants' vagal tone (i.e., a physiological index of emotion regulation). To understand the respective contributions of both parents, as well as the interrelations between the functioning of both dyads within a family, we observed mothers and fathers from 84 families interacting with their infants.

Methods

Synchrony was assessed by using the CARE-Index; infants' vagal tone was derived from the analysis of infants' electrocardiograms recorded during the interactions. Moreover, to take the play's order into account, we counterbalanced the procedure, so that approximately half of the mothers played first. We specified a first structural equation modeling (SEM) model to investigate the associations between interactive synchrony and the infants' root mean square of successive differences (RMSSD), an index of vagal regulation, in the two successive parts of the play. We conducted a multigroup analysis in a second SEM model to investigate the associations of the first SEM model in two groups based on the order of interaction.

Results

The results of the SEM models showed that greater synchrony was related to greater infant RMSSD within mother-infant dyads and across one dyad to the other dyad in the full sample and in the group of fathers who interacted first with the infants. The associations between synchrony and infant vagal tone within father-infant dyads never appeared to be significant, nor did any associations within each dyad and across dyads when mothers interacted first.

Discussion

This study highlights that the links between interactions and infants' vagal tone are sensitive to family members' interdependencies and some conditions (the order of interaction).

Association of Self-Reported Autonomic Symptoms With Sensor-Based Physiological Measures

OBJECTIVE

Autonomic regulation of organ and tissues may give rise to disruptions of typical functions. The Body Perception Questionnaire Short Form (BPQ-SF) includes items that were developed to assess autonomic symptoms in daily life. This pair of studies aimed to establish previously unexplored psychometric properties of the BPQ-SF autonomic symptoms scale, develop normative values for clinical and research use, and assess the convergence of self-reports with sensor-based measures.

METHODS

Study 1 reports exploratory and confirmatory factor analysis on BPQ-SF autonomic symptom items from a large US population-based online study ( n = 2048). In study 2, BPQ-SF scores were examined for associations with heart period, respiratory sinus arrhythmia, and skin conductance during seated leg lifts in a community sample ( n = 62).

RESULTS

Study 1 results supported a two-factor supradiaphragmatic and subdiaphragmatic autonomic symptom solution (confirmatory factor analysis: root mean squared error of approximation = 0.040, Comparative Fit Index = 0.99, Tucker-Lewis Index = 0.99), although a one-factor solution also fit the data well (root mean squared error of approximation = 0.080, Comparative Fit Index = 0.99, Tucker-Lewis Index = 0.99). In study 2, heart period responses to leg lifts and rests were demonstrated at all autonomic symptom levels. However, low autonomic symptoms were associated with optimal autonomic nervous system patterns of activation and recovery to baseline levels. Moderate symptoms were associated with prolonged sympathetic activation. The highest symptom levels were associated with impaired autonomic nervous system coordination across activation and recovery.

CONCLUSIONS

Results support the utility of self-reports of autonomic symptoms in research and clinical applications, with higher symptoms likely indicating autonomic impairment.

The integrative process promoted by EMDR in dissociative disorders: neurobiological mechanisms, psychometric tools, and intervention efficacy on the psychological impact of the COVID-19 pandemic

Dissociative disorders (DDs) are characterized by a discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, bodily representation, motor control, and action. The life-threatening coronavirus disease 2019 (COVID-19) pandemic has been identified as a potentially traumatic event and may produce a wide range of mental health problems, such as depression, anxiety disorders, sleep disorders, and DD, stemming from pandemic-related events, such as sickness, isolation, losing loved ones, and fear for one's life. In our conceptual analysis, we introduce the contribution of the structural dissociation of personality (SDP) theory and polyvagal theory to the conceptualization of the COVID-19 pandemic-triggered DD and the importance of assessing perceived safety in DD through neurophysiologically informed psychometric tools. In addition, we analyzed the contribution of eye movement desensitization and reprocessing (EMDR) to the treatment of the COVID-19 pandemic-triggered DD and suggest possible neurobiological mechanisms of action of the EMDR. In particular, we propose that, through slow eye movements, the EMDR may promote an initial non-rapid-eye-movement sleep stage 1-like activity, a subsequent access to a slow-wave sleep activity, and an oxytocinergic neurotransmission that, in turn, may foster the functional coupling between paraventricular nucleus and both sympathetic and parasympathetic cardioinhibitory nuclei. Neurophysiologically informed psychometric tools for safety evaluation in DDs are discussed. Furthermore, clinical and public health implications are considered, combining the EMDR, SDP theory, and polyvagal conceptualizations in light of the potential dissociative symptomatology triggered by the COVID-19 pandemic.

Knowledge gaps in optimal umbilical cord management at birth

In 2014 the World Health Organisation recommended providing placental blood to all newborn infants by waiting for at least one minute before clamping the umbilical cord. Mounting evidence supports providing a placental transfusion at the time of birth for all infants. The optimal time before clamping and cutting the umbilical cord is still not yet known, and debate exists around other cord management issues. The newborn's transition phase from intra- to extra-uterine life and the effects of blood volume on the many necessary adaptations are understudied. How best to support these adaptations guides our suggested research questions. Parents' perceptions of enrolling their unborn infant into a study play important parts in the conduct of such trials. This article aims to address these topics and suggest research questions for further studies.

A Pilot Study of a Three-Session Heart Rate Variability Biofeedback Intervention for Veterans with Posttraumatic Stress Disorder

Many veterans do not complete traditional trauma treatments; others may continue to struggle with posttraumatic stress disorder (PTSD) even after completing a full course of therapy (Blasé et al., in Int J Environ Res Public Health 18(7):Article 3329, https://doi.org/10.3390/ijerph18073329 , 2016). Heart rate variability (HRV) biofeedback (HRVB) is a non-invasive, non-pharmacological, breathing-based cardiorespiratory training technique that can reduce trauma symptoms and improve HRV parameters. Prior studies have demonstrated HRVB is well-tolerated by veterans with PTSD symptoms (Tan et al., in Appl Psychophysiol Biofeedback 36(1):27-35, 10.1007/s10484-010-9141-y, 2011; Schuman and Killian, in Appl Psychophysiol Biofeedback 44(1):9-20, https://doi.org/10.1007/s10484-018-9415-3 , 2019). This randomized wait-list controlled pilot study tested a short mobile app-adapted HRVB intervention in combination with treatment as usual for veterans with military-related PTSD to determine if further investigation was warranted. We assessed veterans' military-related PTSD symptoms, depression symptoms, and HRV time and frequency domain measures at baseline, after three clinical sessions, and one month later. This study combined clinical training and home biofeedback with a smartphone app and sensor to reinforce training and validate adherence. In the intervention group, depression and SDNN significantly improved, and we observed marginally significant improvements for PTSD Cluster B (intrusion) symptoms, whereas no significant improvements were observed in the control group. In addition, the brief protocol was acceptable to veterans with PTSD with over 83% of participants completing the study. However, adherence to home practice was low. Findings suggest brief HRVB interventions can decrease comorbid depression and improve overall autonomic function in veterans with PTSD; however, additional research on home biofeedback is necessary to determine the best strategies to increase adherence and which veterans would benefit from brief HRVB interventions.

Cardiac Asystole at Birth Re-Visited: Effects of Acute Hypovolemic Shock

Births involving shoulder dystocia or tight nuchal cords can deteriorate rapidly. The fetus may have had a reassuring tracing just before birth yet may be born without any heartbeat (asystole). Since the publication of our first article on cardiac asystole with two cases, five similar cases have been published. We suggest that these infants shift blood to the placenta due to the tight squeeze of the birth canal during the second stage which compresses the cord. The squeeze transfers blood to the placenta via the firm-walled arteries but prevents blood returning to the infant via the soft-walled umbilical vein. These infants may then be born severely hypovolemic resulting in asystole secondary to the loss of blood. Immediate cord clamping (ICC) prevents the newborn's access to this blood after birth. Even if the infant is resuscitated, loss of this large amount of blood volume may initiate an inflammatory response that can enhance neuropathologic processes including seizures, hypoxic-ischemic encephalopathy (HIE), and death. We present the role of the autonomic nervous system in the development of asystole and suggest an alternative algorithm to address the need to provide these infants intact cord resuscitation. Leaving the cord intact (allowing for return of the umbilical cord circulation) for several minutes after birth may allow most of the sequestered blood to return to the infant. Umbilical cord milking may return enough of the blood volume to restart the heart but there are likely reparative functions that are carried out by the placenta during the continued neonatal-placental circulation allowed by an intact cord.

Compassion Focused Group Therapy for People With a Diagnosis of Bipolar Affective Disorder: A Feasibility Study

Background

Compassion focused therapy (CFT) is an evolutionary informed, biopsychosocial approach to mental health problems and therapy. It suggests that evolved motives (e.g., for caring, cooperating, competing) are major sources for the organisation of psychophysiological processes which underpin mental health problems. Hence, evolved motives can be targets for psychotherapy. People with certain types of depression are psychophysiologically orientated towards social competition and concerned with social status and social rank. These can give rise to down rank-focused forms of social comparison, sense of inferiority, worthlessness, lowered confidence, submissive behaviour, shame proneness and self-criticism. People with bipolar disorders also experience elevated aspects of competitiveness and up rank status evaluation. These shift processing to a sense of superiority, elevated confidence, energised behaviour, positive affect and social dominance. This is the first study to explore the feasibility of a 12 module CFT group, tailored to helping people with a diagnosis of bipolar disorder understand the impact of evolved competitive, status-regulating motivation on their mental states and the value of cultivating caring and compassion motives and their psychophysiological regulators.

Methods

Six participants with a history of bipolar disorder took part in a CFT group consisting of 12 modules (over 25 sessions) as co-collaborators to explore their personal experiences of CFT and potential processes of change. Assessment of change was measured via self-report, heart rate variability (HRV) and focus groups over three time points.

Results

Although changes in self-report scales between participants and across time were uneven, four of the six participants consistently showed improvements across the majority of self-report measures. Heart rate variability measures revealed significant improvement over the course of the therapy. Qualitative data from three focus groups revealed participants found CFT gave them helpful insight into: how evolution has given rise to a number of difficult problems for emotion regulation (called tricky brain) which is not one's fault; an evolutionary understanding of the nature of bipolar disorders; development of a compassionate mind and practices of compassion focused visualisations, styles of thinking and behaviours; addressing issues of self-criticism; and building a sense of a compassionate identity as a means of coping with life difficulties. These impacted their emotional regulation and social relationships.

Conclusion

Although small, the study provides evidence of feasibility, acceptability and engagement with CFT. Focus group analysis revealed that participants were able to switch from competitive focused to compassion focused processing with consequent improvements in mental states and social behaviour. Participants indicated a journey over time from 'intellectually' understanding the process of building a compassionate mind to experiencing a more embodied sense of compassion that had significant impacts on their orientation to (and working with) the psychophysiological processes of bipolar disorder.

Respiratory Sinus Arrhythmia Change during Trauma-Focused Cognitive-Behavioral Therapy: Results from a Randomized Controlled Feasibility Trial

Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT) is a well-established treatment for pediatric posttraumatic stress disorder (PTSD). Animal-assisted therapy (AAT) has been proposed as an adjunct to TF-CBT that may improve treatment effects through enhanced targeting of affect regulation, as indexed by specific changes in the respiratory sinus arrhythmia (RSA). The current study reports results from a randomized controlled feasibility trial (N = 33; M_age = 11.79 [SD = 3.08]; 64% White; 67% female) that measured RSA during Sessions 1, 4, 8, and 12 of a twelve-session TF-CBT protocol and tested whether: 1) TF-CBT + AAT achieved higher average RSA amplitudes relative to TF-CBT alone, and 2) RSA regulation, defined as less variability around person-specific RSA slopes during treatment, explained variation in post-treatment PTSD symptoms. Multilevel modeling failed to support an effect for TF-CBT + AAT on RSA amplitudes (δ₀₀₁ = 0.08, p = 0.844). However, regardless of treatment condition, greater RSA withdrawal was observed within Sessions 4 (γ₁₁ = -.01, p < .001) and 12 (γ₁₃ = -.01, p = .015) relative to the Session 1 baseline. The average level of RSA amplitude in Session 8 was also significantly lower compared to Session 1 (γ₀₂ = -0.70, p = .046). Intraindividual regression models demonstrated that greater RSA regulation predicted improved PTSD symptoms at post-treatment after adjusting for pre-treatment levels (b₃ = 20.00, p = .012). These preliminary results offer support for future confirmatory trials testing whether affect regulation, as indexed by changes in RSA, is a mechanism of action for TF-CBT in the treatment of pediatric PTSD.

Making the Argument for Intact Cord Resuscitation: A Case Report and Discussion

We use a case of intact cord resuscitation to argue for the beneficial effects of an enhanced blood volume from placental transfusion for newborns needing resuscitation. We propose that intact cord resuscitation supports the process of physiologic neonatal transition, especially for many of those newborns appearing moribund. Transfer of the residual blood in the placenta provides the neonate with valuable access to otherwise lost blood volume while changing from placental respiration to breathing air. Our hypothesis is that the enhanced blood flow from placental transfusion initiates mechanical and chemical forces that directly, and indirectly through the vagus nerve, cause vasodilatation in the lung. Pulmonary vascular resistance is thereby reduced and facilitates the important increased entry of blood into the alveolar capillaries before breathing commences. In the presented case, enhanced perfusion to the brain by way of an intact cord likely led to regained consciousness, initiation of breathing, and return of tone and reflexes minutes after birth. Paramount to our hypothesis is the importance of keeping the umbilical cord circulation intact during the first several minutes of life to accommodate physiologic neonatal transition for all newborns and especially for those most compromised infants.

Adult attachment style and salivary alpha-amylase and emotional responses to a psychosocial stressor in women with eating disorders

BACKGROUND

The fine-tuning of the endogenous stress response system, which includes the hypothalamus-pituitary-adrenal axis and the sympathetic nervous system (SNS), is influenced by early attachment relationships. A higher prevalence of insecure attachment has been detected in people with eating disorders (EDs). Thus, we investigated the emotional and the SNS reactivity to the Trier Social Stress Test (TSST) in women with EDs in relation to their attachment profiles.

METHODS

Fifty women with EDs and 20 healthy women participated into an experimental study. Attachment was evaluated by Experience in Close Relationship questionnaire. Salivary α-amylase (sAA) levels were measured to assess the SNS reactivity to TSST while the emotional response was measured by the STAI state scale.

RESULTS

Compared to women with EDs and low attachment anxiety and healthy controls, women with EDs and high attachment anxiety showed lower TSST-induced sAA production without difference in anxiety scores. Women with EDs and high attachment avoidance showed similar sAA response to TSST but higher levels of anxiety scores compared to those with low attachment avoidance and healthy controls.

CONCLUSIONS

Our findings corroborate the idea that adult attachment may be associated with variability in emotional and biological responses to a psychosocial stressor in women with EDs.

Towards an expanded neuroscientific understanding of social play

Play has been recognized as a complex and diverse set of behaviors that has been difficult to define. Play can range from rough and tumble play among rats to a human child playing a computer game. Play has been understood to exist in multiple forms such as social, object, and locomotor (Burghardt, 2005). In this article we review the literatures on the neural basis of social play, on heart rate variability, on behavioral switching and set-shifting, on prepulse inhibition of the acoustic startle reflex, and on learning at the level of the basal ganglia. Each of these neuronal pathways, aside from heart rate variability, is rooted in the parafascicular nucleus of the thalamus, an important neural substrate for social play. We argue that social play optimally balances a number of opposing neural pathways by engaging systems involved in safety versus danger (heart rate variability), automatized reactions versus learned reactions to new stimuli (behavioral switching and set-shifting), and gating relevant versus less relevant stimuli (prepulse inhibition of the acoustic startle reflex). The idea that play, in addition to its role in interpersonal adaptation to social life, may have a central role in optimizing flexibility and creativity in individual response to novelty has been explored by previous authors (Huizinga, 1955; Spinka et al., 2001; Pellegrini et al., 2007; Pellis and Pellis, 2017). In this paper we explore the possible underlying neural basis for this function of play, having to do with balancing various neural networks, and in doing so propose an expanded understanding of the nature and function of social play.