Exploring the multidimensional complex systems structure of the stress response and its relation to health and sleep outcomes.

To gain a comprehensive understanding of the multidimensional complex systems structure of the stress response and related health outcomes, we utilized network analysis in a sample of 328 healthy participants in two steps. In a first step, we focused on associations between measures of basal hypothalamic-pituitary-adrenal axis functioning and subjective stress perceptions. In a second step, we linked these diverse stress-related measures to biomarkers and self-reports of health and sleep. Overall, measures clustered depending on their method of assessment, with high correlations between different saliva-based indices of diurnal cortisol regulation, between cortisol and cortisone levels in hair, between different biological health indicators (systemic inflammatory activity and body mass index), between state (experience sampling) and trait (questionnaire-based) self-reports of stress and wellbeing, and between different self-reports of sleep. Bridges between clusters suggested that if individuals perceive stress throughout their daily lives this is reflected in their total salivary cortisol output possibly contributing to long-term cortisol accumulation in hair. Likewise, earlier awakening time may contribute to cortisol accumulation in hair via an influence on awakening cortisol processes. Our results show that while meaningful connections between measures exist, stress is a highly complex construct composed of numerous aspects. We argue that network analysis is an integrative statistical approach to address the multidimensionality of the stress response and its effects on the brain and body. This may help uncover pathways to stress-related disease and serve to identify starting points for prevention and therapeutic intervention.

Specific reduction in cortisol stress reactivity after social but not attention-based mental training.

Psychosocial stress is a public health burden in modern societies. Chronic stress-induced disease processes are, in large part, mediated via the activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary system. We asked whether the contemplative mental training of different practice types targeting attentional, socio-affective (for example, compassion), or socio-cognitive abilities (for example, perspective-taking) in the context of a 9-month longitudinal training study offers an effective means for psychosocial stress reduction. Using a multimethod approach including subjective, endocrine, autonomic, and immune markers and testing 313 participants in a standardized psychosocial laboratory stressor, we show that all three practice types markedly reduced self-reported stress reactivity in healthy participants. However, only the training of intersubjective skills via socio-affective and socio-cognitive routes attenuated the physiological stress response, specifically the secretion of the HPA axis end-product cortisol, by up to 51%. The assessed autonomic and innate immune markers were not influenced by any practice type. Mental training focused on present-moment attention and interoceptive awareness as implemented in many mindfulness-based intervention programs was thus limited to stress reduction on the level of self-report. However, its effectiveness was equal to that of intersubjective practice types in boosting the association between subjective and endocrine stress markers. Our results reveal a broadly accessible low-cost approach to acquiring psychosocial stress resilience. Short daily intersubjective practice may be a promising method for minimizing the incidence of chronic social stress-related disease, thereby reducing individual suffering and relieving a substantial financial burden on society.

Influences of oxytocin and respiratory sinus arrhythmia on emotions and social behavior in daily life.

The literature concerning biological influences on positive social behavior shows that, in nonthreatening contexts, tonic oxytocin (OT) and respiratory sinus arrhythmia (RSA) each predict positive, affiliative behaviors toward certain others and are associated with positive health outcomes. The purpose of this investigation was to determine the degree to which the positive affiliative correlates of OT and RSA can be distinguished when observed at the level of everyday life events. A sample of midlife adults (N = 73) provided tonic indices of these biological characteristics, as well as perceptions of a variety of common life events alongside reports of their emotions during those events. OT and RSA each independently moderated the link between perceived event sociality and positive emotions, whereas only RSA predicted the probability of being with other people during an event. These findings suggest that OT and RSA may each be linked to positive social experiences in complementary yet distinct ways. (PsycINFO Database Record

Phenomenological Fingerprints of Four Meditations: Differential State Changes in Affect, Mind-Wandering, Meta-Cognition, and Interoception Before and After Daily Practice Across 9 Months of Training.

Despite increasing interest in the effects of mental training practices such as meditation, there is much ambiguity regarding whether and to what extent the various types of mental practice have differential effects on psychological change. To address this gap, we compare the effects of four common meditation practices on measures of state change in affect, mind-wandering, meta-cognition, and interoception. In the context of a 9-month mental training program called the ReSource Project, 229 mid-life adults (mean age 41) provided daily reports before and after meditation practice. Participants received training in the following three successive modules: the first module (presence) included breathing meditation and body scan, the second (affect) included loving-kindness meditation, and the third (perspective) included observing-thought meditation. Using multilevel modeling, we found that body scan led to the greatest state increase in interoceptive awareness and the greatest decrease in thought content, loving-kindness meditation led to the greatest increase in feelings of warmth and positive thoughts about others, and observing-thought meditation led to the greatest increase in meta-cognitive awareness. All practices, including breathing meditation, increased positivity of affect, energy, and present focus and decreased thought distraction. Complementary network analysis of intervariate relationships revealed distinct phenomenological clusters of psychological change congruent with the content of each practice. These findings together suggest that although different meditation practices may have common beneficial effects, each practice can also be characterized by a distinct short-term psychological fingerprint, the latter having important implications for the use of meditative practices in different intervention contexts and with different populations.

Effects of Contemplative Dyads on Engagement and Perceived Social Connectedness Over 9 Months of Mental Training: A Randomized Clinical Trial.

IMPORTANCE: Loneliness is a risk factor for depression and other illnesses and may be caused and reinforced by maladaptive social cognition. Secularized classical meditation training programs address social cognition, but practice typically occurs alone. Little is known about the effectiveness of contemplative practice performed in dyads. OBJECTIVE: To introduce and assess the effectiveness of contemplative dyadic practices relative to classical-solitary meditation with regard to engagement and perceived social connectedness. DESIGN, SETTING, AND PARTICIPANTS: The ReSource Project was a 9-month open-label efficacy trial of three, 3-month secularized mental training modules. Replacement randomization was used to assign 362 healthy participants in Leipzig and Berlin, Germany. Eligible participants were recruited between November 11, 2012, and February 13, 2013, and between November 13, 2013, and April 30, 2014. Intention-to-treat analyses were conducted. INTERVENTIONS: Breathing meditation and body scan (the presence module), loving-kindness meditation and affect dyad (the affect module), and observing-thoughts meditation and perspective dyad (the perspective module). MAIN OUTCOMES AND MEASURES: Primary outcomes were self-disclosure and social closeness. Engagement measures included compliance (ie, the mean [95% margin of error] number of meditation sessions that a participant engaged in per week), liking, and motivation to practice. RESULTS: Thirty participants dropped out after assignment to 3 experimental groups; 90 participants were assigned to a retest control that did not complete the main outcome measures; 16 participants provided no state-change data for the affect and perspective modules (226 remaining participants; mean age of 41.15 years; 59.3% female). Results are aggregated across training cohorts. Compliance was similar across the modules: loving-kindness meditation (3.78 [0.18] sessions), affect dyad (3.59 [0.14] sessions), observing-thoughts meditation (3.63 [0.20] sessions), and perspective dyad (3.24 [0.18] sessions). Motivation was higher for meditation (11.20 [0.40] sessions) than the dyads (9.26 [0.43] sessions) and was higher for the affect dyad (10.11 [0.46] sessions) than the perspective dyad (8.41 [0.46] sessions). Social closeness increased during a session for the affect dyad (1.49 [0.12] sessions) and the perspective dyad (1.06 [0.12] sessions) and increased over time for the affect dyad (slope of 0.016 [0.003]) and the perspective dyad (slope of 0.012 [0.003]). Self-disclosure increased over time for the affect dyad (slope of 0.023 [0.004]) and the perspective dyad (slope of 0.006 [0.005]), increasing more steeply for the affect dyad (P < .001). CONCLUSIONS AND RELEVANCE: Contemplative dyads elicited engagement similar to classical contemplative practices and increased perceived social connectedness. Contemplative dyads represent a new type of intervention targeting social connectedness and intersubjective capacities deficient in participants who experience loneliness and in many psychopathologies. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01833104.

Helping from the heart: Voluntary upregulation of heart rate variability predicts altruistic behavior.

Our various daily activities continually require regulation of our internal state. These regulatory processes covary with changes in High Frequency Heart Rate Variability (HF-HRV), a marker of parasympathetic activity. Specifically, incidental increases in HF-HRV accompany positive social engagement behavior and prosocial action. Little is known about deliberate regulation of HF-HRV and the role of voluntary parasympathetic regulation in prosocial behavior. Here, we present a novel biofeedback task that measures the ability to deliberately increase HF-HRV. In two large samples, we find that a) participants are able to voluntarily upregulate HF-HRV, and b) variation in this ability predicts individual differences in altruistic prosocial behavior, but not non-altruistic forms of prosociality, assessed through 14 different measures. Our findings suggest that self-induction of parasympathetic states is involved in altruistic action. The biofeedback task may provide a measure of deliberate parasympathetic regulation, with implications for the study of attention, emotion, and social behavior.

Is meditation always relaxing? Investigating heart rate, heart rate variability, experienced effort and likeability during training of three types of meditation.

Meditation is often associated with a relaxed state of the body. However, meditation can also be regarded as a type of mental task and training, associated with mental effort and physiological arousal. The cardiovascular effects of meditation may vary depending on the type of meditation, degree of mental effort, and amount of training. In the current study we assessed heart rate (HR), high-frequency heart rate variability (HF-HRV) and subjective ratings of effort and likeability during three types of meditation varying in their cognitive and attentional requirements, namely breathing meditation, loving-kindness meditation and observing-thoughts meditation. In the context of the ReSource project, a one-year longitudinal mental training study, participants practiced each meditation exercise on a daily basis for 3 months. As expected HR and effort were higher during loving-kindness meditation and observing-thoughts meditation compared to breathing meditation. With training over time HR and likeability increased, while HF-HRV and the subjective experience of effort decreased. The increase in HR and decrease in HF-HRV over training was higher for loving-kindness meditation and observing-thoughts meditation compared to breathing meditation. In contrast to implicit beliefs that meditation is always relaxing and associated with low arousal, the current results show that core meditations aiming at improving compassion and meta-cognitive skills require effort and are associated with physiological arousal compared to breathing meditation. Overall these findings can be useful in making more specific suggestions about which type of meditation is most adaptive for a given context and population.

How positive emotions build physical health: perceived positive social connections account for the upward spiral between positive emotions and vagal tone.

The mechanisms underlying the association between positive emotions and physical health remain a mystery. We hypothesize that an upward-spiral dynamic continually reinforces the tie between positive emotions and physical health and that this spiral is mediated by people's perceptions of their positive social connections. We tested this overarching hypothesis in a longitudinal field experiment in which participants were randomly assigned to an intervention group that self-generated positive emotions via loving-kindness meditation or to a waiting-list control group. Participants in the intervention group increased in positive emotions relative to those in the control group, an effect moderated by baseline vagal tone, a proxy index of physical health. Increased positive emotions, in turn, produced increases in vagal tone, an effect mediated by increased perceptions of social connections. This experimental evidence identifies one mechanism-perceptions of social connections-through which positive emotions build physical health, indexed as vagal tone. Results suggest that positive emotions, positive social connections, and physical health influence one another in a self-sustaining upward-spiral dynamic.

Upward spirals of the heart: autonomic flexibility, as indexed by vagal tone, reciprocally and prospectively predicts positive emotions and social connectedness.

Vagal tone (VT), an index of autonomic flexibility, is linked to social and psychological well-being. We posit that the association between VT and well-being reflects an "upward spiral" in which autonomic flexibility, represented by VT, facilitates capitalizing on social and emotional opportunities and the resulting opportunistic gains, in turn, lead to higher VT. Community-dwelling adults were asked to monitor and report their positive emotions and the degree to which they felt socially connected each day for 9 weeks. VT was measured at the beginning and end of the 9-week period. Adults who possessed higher initial levels of VT increased in connectedness and positive emotions more rapidly than others. Furthermore, increases in connectedness and positive emotions predicted increases in VT, independent of initial VT level. This evidence is consistent with an "upward spiral" relationship of reciprocal causality, in which VT and psychosocial well-being reciprocally and prospectively predict one another.

Estimating and Visualizing Nonlinear Relations Among Latent Variables: A Semiparametric Approach.

The graphical presentation of any scientific finding enhances its description, interpretation, and evaluation. Research involving latent variables is no exception, especially when potential nonlinear effects are suspect. This article has multiple aims. First, it provides a nontechnical overview of a semiparametric approach to modeling nonlinear relationships among latent variables using mixtures of linear structural equations. Second, it provides several examples showing how the method works and how it is implemented and interpreted in practical applications. In particular, this article examines the potentially nonlinear relationships between positive and negative affect and cognitive processing. Third, a recommended display format for illustrating latent bivariate relationships is demonstrated. Finally, the article describes an R package and an online utility that generate these displays automatically.