Multi-ethnic variation in the ties that bind rumination and heart rate variability: Implications for health disparities.

Higher self-reported rumination, a common form of trait perseverative cognition, is linked with lower resting heart rate variability (HRV), which indicates poorer cardiac function and greater disease risk. A meta-analysis and systematic review indicated that in samples with fewer European Americans, the association of rumination with both heart rate and blood pressure was stronger. Thus, trait rumination may be more strongly associated with resting HRV among ethnically minoritized populations.

Assessing New Methods to Optimally Detect Episodes of Non-metabolic Heart Rate Variability Reduction as an Indicator of Psychological Stress in Everyday Life: A Thorough Evaluation of Six Methods.

Frequent or chronic reduction in heart rate variability (HRV) is a powerful predictor of cardiovascular disease, and psychological stress has been suggested to be a co-determinant of this reduction. Recently, we evaluated various methods to measure additional HRV reduction in everyday life and to relate these reductions to psychological stress. In the current paper, we thoroughly evaluate these methods and add two new methods in both newly acquired and reanalyzed datasets.

Reduced Heart Rate Variability in Patients With Medically Unexplained Physical Symptoms: A Meta-Analysis of HF-HRV and RMSSD.

Objective: Medically unexplained physical symptoms (MUPS) and related syndromes are common and place a substantial burden on both patients and society. Chronic psychological distress and dysregulation of the autonomic nervous system may be common factors associated with MUPS, although previous studies have reported mixed results. The aims of this meta-analysis are to provide an updated synthesis of studies investigating heart rate variability (HRV) indices associated with autonomic nervous system functioning in three common MUPS syndromes and to explain inconsistencies in previous study findings.

Better Safe Than Sorry: A Common Signature of General Vulnerability for Psychopathology.

Several labels, such as neuroticism, negative emotionality, and dispositional negativity, indicate a broad dimension of psychopathology. However, largely separate, often disorder-specific research lines have developed that focus on different cognitive and affective characteristics that are associated with this dimension, such as perseverative cognition (worry, rumination), reduced autobiographical memory specificity, compromised fear learning, and enhanced somatic-symptom reporting. In this article, we present a theoretical perspective within a predictive-processing framework in which we trace these phenotypically different characteristics back to a common underlying "better-safe-than-sorry" processing strategy.

From ear to eye? No effect of transcutaneous vagus nerve stimulation on human pupil dilation: A report of three studies.

Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) has been proposed as a treatment for a spectrum of physical and psychological disorders. One of the proposed working mechanisms of tVNS is a modulatory effect on the locus coeruleus - noradrenaline (LC-NA) network. We tested this hypothesis in humans in a series of three studies: one focusing on high trait worriers, and two in healthy populations.

The effect of transcutaneous vagus nerve stimulation on fear generalization and subsequent fear extinction.

Fear overgeneralization is thought to be one of the cardinal processes underlying anxiety disorders, and a determinant of the onset, maintenance and recurrence of these disorders. Animal studies have shown that stimulating the vagus nerve (VNS) affects neuronal pathways implicated in pattern separation and completion, suggesting it may reduce the generalization of a fear memory to novel situations. In a one-day study, 58 healthy students were subjected to a fear conditioning, fear generalization, and fear extinction paradigm.

Transcutaneous vagus nerve stimulation reduces spontaneous but not induced negative thought intrusions in high worriers.

Worrying is a central component of anxiety disorders. We tested whether non-invasive vagus nerve stimulation reduces negative thought intrusions in high worriers. Worry was assessed with a Breathing Focus Task, which consists of a pre-worry period, a worry induction, and a post-worry period.

Transcutaneous vagus nerve stimulation and extinction of prepared fear: A conceptual non-replication.

Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) may accelerate fear extinction in healthy humans. Here, we aimed to investigate this hypothesis in healthy young participants in a prepared learning paradigm, using spider pictures as conditioned stimuli. After a fear conditioning phase, participants were randomly allocated to receive tVNS (final N = 42) or sham stimulation (final N = 43) during an extinction phase.

Generalized Unsafety Theory of Stress: Unsafe Environments and Conditions, and the Default Stress Response.

Prolonged physiological stress responses form an important risk factor for disease. According to neurobiological and evolution-theoretical insights the stress response is a default response that is always "on" but inhibited by the prefrontal cortex when safety is perceived. Based on these insights the Generalized Unsafety Theory of Stress (GUTS) states that prolonged stress responses are due to generalized and largely unconsciously perceived unsafety rather than stressors.

Heart rate variability mediates the link between rumination and depressive symptoms: A longitudinal study.

Ruminative thinking about negative feelings has been prospectively associated with increases in depressive symptoms and heightened risk for new onsets of major depression. One putative pathophysiological mechanism underlying this link might be represented by autonomic nervous system dysfunction. The objective of this longitudinal study was to evaluate the interplay between rumination, autonomic function (as revealed by heart rate variability (HRV) analysis), and depressive symptoms in healthy young subjects, over a three-year period.

New methods to optimally detect episodes of non-metabolic heart rate variability reduction as an indicator of psychological stress in everyday life.

Cardiovascular disease is the leading cause of death in the western world. Frequent or chronic reductions in heart rate variability (HRV) are a powerful predictor of cardiovascular disease. Psychological stress has been suggested to be an important factor in the development of reduced HRV.

Peripheral physiological responses to subliminally presented negative affective stimuli: A systematic review.

Negative affective information may be presented outside of awareness and change physiological activity. By increasing peripheral physiological activity, subliminally presented negative affective information may contribute to the development of disease. The current systematic review evaluated 65 studies in which negative affective stimuli were presented subliminally to a healthy sample while cardiovascular, electrodermal, electromyographical, hormonal, or immunological activity was measured.

Converging evidence that subliminal evaluative conditioning does not affect self-esteem or cardiovascular activity.

Self-esteem moderates the relationship between stress and (cardiovascular) health, with low self-esteem potentially exacerbating the impact of stressors. Boosting self-esteem may therefore help to buffer against stress. Subliminal evaluative conditioning (SEC), which subliminally couples self-words with positive words, has previously been successfully used to boost self-esteem, but the existing studies are in need of replication.

Inducing unconscious stress: Cardiovascular activity in response to subliminal presentation of threatening and neutral words.

Stress-related cognitive processes may occur outside of awareness, here referred to as unconscious stress, and affect one's physiological state. Evidence supporting this idea would provide necessary clarification of the relationship between psychological stress and cardiovascular (CV) health problems. We tested the hypothesis that increases in mean arterial pressure (MAP) and total peripheral resistance (TPR) and decreases in heart rate variability (HRV) would be larger when threatening stimuli are presented outside of awareness, or subliminally, compared with neutral stimuli.

Ever at the ready for events that never happen.

Stress, whether daily stress, work stress or traumatic stress, is unhealthy. This lecture covers three recent theoretical approaches in explaining the mechanisms underlying the influence of psychological stress on somatic health. It is argued that stress research should focus less on stressors themselves and put more emphasis on prolonged stress responses.

Hemodynamic Profiles of Functional and Dysfunctional Forms of Repetitive Thinking.

Background: The ability of the human brain to escape the here and now (mind wandering) can take functional (problem solving) and dysfunctional (perseverative cognition) routes. Although it has been proposed that only the latter may act as a mediator of the relationship between stress and cardiovascular disease, both functional and dysfunctional forms of repetitive thinking have been associated with blood pressure (BP) reactivity of the same magnitude. However, a similar BP reactivity may be caused by different physiological determinants, which may differ in their risk for cardiovascular pathology.

Exposed to events that never happen: Generalized unsafety, the default stress response, and prolonged autonomic activity.

Based on neurobiological and evolutionary arguments, the generalized unsafety theory of stress (GUTS) hypothesizes that the stress response is a default response, and that chronic stress responses are caused by generalized unsafety (GU), independent of stressors or their cognitive representation. Three highly prevalent conditions are particularly vulnerable to becoming 'compromised' in terms of GU, and carry considerable health risks: Thus, GUTS critically revises and expands stress theory, by focusing on safety instead of threat, and by including risk factors that have hitherto not been attributed to stress.

Changing Mental Health and Positive Psychological Well-Being Using Ecological Momentary Interventions: A Systematic Review and Meta-analysis.

Background: Mental health problems are highly prevalent, and there is need for the self-management of (mental) health. Ecological momentary interventions (EMIs) can be used to deliver interventions in the daily life of individuals using mobile devices.

Objectives: The aim of this study was to systematically assess and meta-analyze the effect of EMI on 3 highly prevalent mental health outcomes (anxiety, depression, and perceived stress) and positive psychological outcomes (eg, acceptance).

The default response to uncertainty and the importance of perceived safety in anxiety and stress: An evolution-theoretical perspective.

From a combined neurobiological and evolution-theoretical perspective, the stress response is a subcortically subserved response to uncertainty that is not 'generated' but 'default': the stress response is 'always there' but as long as safety is perceived, the stress response is under tonic prefrontal inhibition, reflected by high vagally mediated heart rate variability. Uncertainty of safety leads to disinhibiting the default stress response, even in the absence of threat. Due to the stress response's survival value, this 'erring on the side of caution' is passed to us via our genes.

The effects of transcutaneous vagus nerve stimulation on conditioned fear extinction in humans.

A critical component of the treatment for anxiety disorders is the extinction of fear via repeated exposure to the feared stimulus. This process is strongly dependent on successful memory formation and consolidation. Stimulation of the vagus nerve enhances memory formation in both animals and humans.

Prolonged Non-metabolic Heart Rate Variability Reduction as a Physiological Marker of Psychological Stress in Daily Life.

Background: Prolonged cardiac activity that exceeds metabolic needs can be detrimental for somatic health. Psychological stress could result in such "additional cardiac activity."

Purpose: In this study, we examined whether prolonged additional reductions in heart rate variability (AddHRVr) can be measured in daily life with an algorithm that filters out changes in HRV that are purely due to metabolic demand, as indexed by movement, using a brief calibration procedure.

The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses.

Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors.

Physiological concomitants of perseverative cognition: A systematic review and meta-analysis.

Rumination about the past and worries about the future (perseverative cognition) are extremely common, although pervasive and distressing, dysfunctional cognitive processes. Perseverative cognition is not only implicated in psychological health, contributing to mood worsening and psychopathology but, due to its ability to elicit prolonged physiological activity, is also considered to play a role in somatic health. Although there is emerging evidence that such negative and persistent thoughts have consequences on the body, this association has not yet been quantified.