Heart rate variability, the vagus and calm.
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626 to 650 of 1,007Investigating the relationship between cardiac interoception and autonomic cardiac control using a predictive coding framework.
Predictive coding models, such as the 'free-energy principle' (FEP), have recently been discussed in relation to how interoceptive (afferent visceral feedback) signals update predictions about the state of the body, thereby driving autonomic mediation of homeostasis. This study appealed to 'interoceptive inference', under the FEP, to seek new insights into autonomic (dys)function and brain-body integration by examining the relationship between cardiac interoception and autonomic cardiac control in healthy controls and patients with forms of orthostatic intolerance (OI); to (i) seek empirical support for interoceptive inference and (ii) delineate if this relationship was sensitive to increased interoceptive prediction error in OI patients during head-up tilt (HUT)/symptom provocation. Measures of interoception and heart rate variability (HRV) were recorded whilst supine and during HUT in …
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Associations between respiratory sinus arrhythmia (RSA) reactivity and effortful control in preschool-age children.
We tested whether respiratory sinus arrhythmia (RSA) reactivity in response to each of three self-regulation tasks (bird and dragon; knock-tap; and gift wrap) would predict self-regulation performance in a sample of 101 preschool-age children (M age = 4.49, SD = .64). While controlling for baseline RSA, decreases in RSA from bird and dragon to knock-tap (but not from baseline to bird and dragon) predicted a latent variable measuring self-regulation. Furthermore, increases in RSA from the knock-tap to gift wrap-the only task involving delay of gratification-were related to concurrent task performance while controlling for the relation between RSA reactivity and the latent self-regulation variable. Results suggest that the relations between RSA reactivity and self-regulatory ability are influenced by task-specific demands and possibly by task order. Furthermore, RSA reactivity appears to r…
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Kermorgant M, Labrunée M, Despas F, Hélissen O, Geeraerts T, Lambert E, Schmidt E, Senard JM, Arvanitis DN, Nasr N, Traon AP (2022)MEDLINE-indexed journal, not yet read by usAutonomic neuroscience : basic & clinical7 citations How does head position induced intracranial pressure changes impact sympathetic activity and cerebral blood flow?
Purpose: Acute head-down-tilt (HDT) simulates short duration hemodynamic impact of microgravity. We sought to determine whether an increase in ICP caused by acute HDT affects sympathetic nervous system activity and cerebral blood flow velocities (CBFV) in healthy male volunteers.
Methods: HDT protocol was established as follows: basal condition immediately followed by gradual negative angles (-10°, -20° and -30°) lasting 10mn and then a return to basal condition. Velocities in the MCA (CBFV) were monitored using TCD. Sympathetic activity was assessed using MSNA. Baroreflex sensitivity (BRS) was measured using the sequence method. ICP changes were assessed using ultrasonography of the optic nerve sheath diameter (ONSD). Cerebral autoregulation (CA) was evaluated by transfer function and the autoregulatory index (Mxa).
Results: Twelve male volunteers (age: 35 ± 2 years) were included. Neit…
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Optimization of Transcutaneous Vagus Nerve Stimulation Using Functional MRI.
Objective/hypothesis: Vagus nerve stimulation (VNS) is an established therapy for drug-resistant epilepsy, depression, and a number of other disorders. Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) has been considered as a non-invasive alternative. Several functional magnetic resonance imaging (fMRI) studies on the effects of tVNS used different stimulation parameters and locations in the ear, which makes it difficult to determine the optimal tVNS methodology. The present study used fMRI to determine the most effective location for tVNS.
Materials and methods: Four stimulation locations in the ear were compared: the inner tragus, inferoposterior wall of the ear canal, cymba conchae, and earlobe (sham). Thirty-seven healthy subjects underwent two 6-min tVNS stimulation runs per electrode location (monophasic rectangular 500 μs pulses, 25 Hz). General linear …
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Decreased emotional reactivity of rats exposed to repeated phase shifts of light-dark cycle.
Disturbed light-dark (LD) cycles are associated with circadian disruption of physiological and behavioural rhythms and in turn with an increased risk of disease development. However, direct causal links and underlying mechanisms leading to negative health consequences still need to be revealed. In the present study, we exposed male Wistar rats to repeated phase shifts of LD cycle and analysed their ability to cope with mild emotional stressors. In experiment 1, rats were submitted to either a regular 12:12 LD cycle (CTRL rats) or 8-h phase delay shifts applied every 2days for 5weeks (SHIFT rats). Subsequently, the behaviour was examined in the open-field, black-white box and elevated plus maze tests. In experiment 2, changes in blood pressure (BP), heart rate (HR) as well as the activity of autonomic nervous system were measured in telemeterised rats in response to open-field and black-w…
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The integration of the internal and external milieu in the insula during dynamic emotional experiences.
Whilst external events trigger emotional responses, interoception (the perception of internal physiological states) is fundamental to core emotional experience. By combining high resolution functional neuroimaging with concurrent physiological recordings, we investigated the neural mechanisms of interoceptive integration during free listening to an emotionally salient audio film. We found that cardiac activity, a key interoceptive signal, was robustly synchronised across participants and centrally represented in the posterior insula. Effective connectivity analysis revealed that the anterior insula, specifically tuned to the emotionally salient moments of the audio stream, serves as an integration hub of interoceptive processing: interoceptive states represented in the posterior insula are integrated with exteroceptive representations by the anterior insula to highlight these emotionally…
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Network interactions within the canine intrinsic cardiac nervous system: implications for reflex control of regional cardiac function.
The aims of the study were to determine how aggregates of intrinsic cardiac (IC) neurons transduce the cardiovascular milieu versus responding to changes in central neuronal drive and to determine IC network interactions subsequent to induced neural imbalances in the genesis of atrial fibrillation (AF). Activity from multiple IC neurons in the right atrial ganglionated plexus was recorded in eight anaesthetized canines using a 16-channel linear microelectrode array. Induced changes in IC neuronal activity were evaluated in response to: (1) focal cardiac mechanical distortion; (2) electrical activation of cervical vagi or stellate ganglia; (3) occlusion of the inferior vena cava or thoracic aorta; (4) transient ventricular ischaemia, and (5) neurally induced AF. Low level activity (ranging from 0 to 2.7 Hz) generated by 92 neurons was identified in basal states, activities that displaye…
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Role of the parasympathetic nervous system in cardioprotection by remote hindlimb ischaemic preconditioning.
This investigation was designed to determine the participation of the vagus nerve and muscarinic receptors in the remote ischaemic preconditioning (rIPC) mechanism. New Zealand rabbits were anaesthetized, and the femoral artery was dissected. After 30 min of monitoring, the hearts were isolated and subjected to 30 min of global no-flow ischaemia and 180 min of reperfusion (non-rIPC group). The ventricular function was evaluated, considering the left ventricular developed pressure and the left ventricular end-diastolic pressure. In the rIPC group, the rabbits were subjected to three cycles of hindlimb ischaemia (5 min) and reperfusion (5 min), and the same protocol as that used in non-rIPC group was then repeated. In order to evaluate the afferent neural pathway during the rIPC protocol we used two groups, one in which the femoral and sciatic nerves were sectioned and the other in which t…
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Neural regulation of inflammation: no neural connection from the vagus to splenic sympathetic neurons.
The 'inflammatory reflex' acts through efferent neural connections from the central nervous system to lymphoid organs, particularly the spleen, that suppress the production of inflammatory cytokines. Stimulation of the efferent vagus has been shown to suppress inflammation in a manner dependent on the spleen and splenic nerves. The vagus does not innervate the spleen, so a synaptic connection from vagal preganglionic neurons to splenic sympathetic postganglionic neurons was suggested. We tested this idea in rats. In a preparatory operation, the anterograde tracer DiI was injected bilaterally into the dorsal motor nucleus of vagus and the retrograde tracer Fast Blue was injected into the spleen. On histological analysis 7-9 weeks later, 883 neurons were retrogradely labelled from the spleen with Fast Blue as follows: 89% in the suprarenal ganglia (65% left, 24% right); 11% in the left coe…
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Hermans EJ, van Marle HJ, Ossewaarde L, Henckens MJ, Qin S, van Kesteren MT, Schoots VC, Cousijn H, Rijpkema M, Oostenveld R, Fernández G (2011)MEDLINE-indexed journal, not yet read by usScience (New York, N.Y.)443 citations Stress-related noradrenergic activity prompts large-scale neural network reconfiguration.
Acute stress shifts the brain into a state that fosters rapid defense mechanisms. Stress-related neuromodulators are thought to trigger this change by altering properties of large-scale neural populations throughout the brain. We investigated this brain-state shift in humans. During exposure to a fear-related acute stressor, responsiveness and interconnectivity within a network including cortical (frontoinsular, dorsal anterior cingulate, inferotemporal, and temporoparietal) and subcortical (amygdala, thalamus, hypothalamus, and midbrain) regions increased as a function of stress response magnitudes. β-adrenergic receptor blockade, but not cortisol synthesis inhibition, diminished this increase. Thus, our findings reveal that noradrenergic activation during acute stress results in prolonged coupling within a distributed network that integrates information exchange between regions involve…
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Autonomic responses to heat pain: Heart rate, skin conductance, and their relation to verbal ratings and stimulus intensity.
In human pain experiments, as well as in clinical settings, subjects are often asked to assess pain using scales (eg, numeric rating scales). Although most subjects have little difficulty in using these tools, some lack the necessary basic cognitive or motor skills (eg, paralyzed patients). Thus, the identification of appropriate nonverbal measures of pain has significant clinical relevance. In this study, we assessed heart rate (HR), skin conductance (SC), and verbal ratings in 39 healthy male subjects during the application of twelve 6-s heat stimuli of different intensities on the subjects' left forearm. Both HR and SC increased with more intense painful stimulation. However, HR but not SC, significantly correlated with pain ratings at the group level, suggesting that HR may be a better predictor of between-subject differences in pain than is SC. Conversely, changes in SC better predi…
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Brain mediators of cardiovascular responses to social threat, part II: Prefrontal-subcortical pathways and relationship with anxiety.
Social evaluative threat (SET) is a potent stressor in humans that causes autonomic changes, endocrine responses, and multiple health problems. Neuroimaging has recently begun to elucidate the brain correlates of SET, but as yet little is known about the mediating cortical-brainstem pathways in humans. This paper replicates and extends findings in a companion paper (Wager et al., 2009) using an independent cohort of participants and different image acquisition parameters. Here, we focused specifically on relationships between the medial prefrontal cortex (MPFC), midbrain periaqueductal gray (PAG), and heart rate (HR). We applied multi-level path analysis to localize brain mediators of SET effects on HR and self-reported anxiety. HR responses were mediated by opposing signals in two distinct sub-regions of the MPFC-increases in rostral dorsal anterior cingulate cortex (rdACC) and de-activ…
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The level of physical activity affects adrenal and cardiovascular reactivity to psychosocial stress.
Physical activity plays a key role in the control of neuroendocrine, autonomic, and behavioral responses to physical and psychosocial stress. However, little is known about how the level of physical activity modulates stress responsiveness. Here, we test whether different levels of physical activity are associated with different adrenal, cardiovascular, and psychological responses to psychosocial stress. In addition, competitiveness is assessed as a personality trait that possibly modulates the relationship between physical activity and stress reactivity. Eighteen elite sportsmen, 50 amateur sportsmen, and 24 untrained men were exposed to a standardized psychosocial laboratory stressor (Trier Social Stress Test). Repeated measures of salivary free cortisol, heart rate, and psychological responses to psychosocial stress were compared among the 3 study groups. Elite sportsmen exhibited sig…
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Stimulation of nicotinic acetylcholine receptors attenuates collagen-induced arthritis in mice.
Objective: The parasympathetic nervous system, through the vagus nerve, can down-regulate inflammation in vivo by decreasing the release of cytokines, including tumor necrosis factor alpha (TNFalpha), by activated macrophages. The vagus nerve may exert antiinflammatory actions via a specific effect of its principal neurotransmitter, acetylcholine, on the alpha7 subunit of nicotinic acetylcholine receptors (alpha7nAChR) on macrophages. The present study was undertaken to obtain insight into the role of the cholinergic antiinflammatory pathway in arthritis.
Methods: To inhibit the cholinergic antiinflammatory pathway, mice were subjected to unilateral cervical vagotomy or sham surgery, after which arthritis was induced with type II collagen. In a separate study, nicotine was added to the drinking water of mice with collagen-induced arthritis (CIA). In addition, we investigated the effects …
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Effects of pre-learning stress on memory for neutral, positive and negative words: Different roles of cortisol and autonomic arousal.
Stress can have enhancing or impairing effects on memory. Here, we addressed the effect of pre-learning stress on subsequent memory and asked whether neutral and emotionally valent information are differentially affected by specific stress components, autonomic arousal and stress-induced cortisol. Ninety-six healthy men and women underwent either a stressor (modified cold pressor test) or a control warm water exposure. During stress, participants showed comparable autonomic arousal (heart rate, blood pressure), while 60 percent showed an increase of cortisol (responders vs. 40 percent non-responders). Ten minutes after the cold pressor test neutral, positive and negative words were presented. Free recall was tested 1 and 24h later. Overall, positive and negative words were better recalled than neutral words. Stress enhanced the recall of neutral words independently of cortisol response. …
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The up- and down-regulation of amusement: experiential, behavioral, and autonomic consequences.
A growing body of research has examined the regulation of negative emotions. However, little is known about the physiological processes underlying the regulation of positive emotions, such as when amusement is enhanced during periods of stress or attenuated in the pursuit of social goals. The aim of this study was to examine the psychophysiological consequences of the cognitive up- and down-regulation of amusement. To address this goal, participants viewed brief, amusing film clips while measurements of experience, behavior, and peripheral physiology were collected. Using an event-related design, participants viewed each film under the instructions either to (a) watch, (b) use cognitive reappraisal to increase amusement, or (c) use cognitive reappraisal to decrease amusement. Findings indicated that emotion experience, emotion-expressive behavior, and autonomic physiology (including hear…
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A robust algorithm for heart rate variability time series artefact correction using novel beat classification.
Purpose: Heart rate variability is a commonly used measurement to evaluate functioning of autonomic nervous system, psychophysiological stress, and exercise intensity and recovery. HRV measurements contain artefacts such as extra, missed or misaligned beat detections, which can produce significant distortion on HRV parameters. In this paper, a robust automatic method for artefact detection from HRV time series is proposed. Methods: The proposed detection method is based on time-varying thresholds estimated from distribution of successive RR-interval differences combined with a novel beat classification scheme. The method is validated using simulated extra, missed and misaligned beat detections as well as real artefacts such as atrial and ventricular ectopic beats. Results: The sensitivity of the algorithm to detect simulated missed/extra beats was 100%. The sensitivity to detect real atr…
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Emotion regulation after acquired brain injury: a study of heart rate variability, attentional control, and psychophysiology.
Primary objective: To examine the efficacy of heart rate variability biofeedback (HRV-BF) to treat emotional dysregulation in persons with acquired brain injury. Design: A secondary analysis of a quasi-experimental study which enrolled 13 individuals with severe chronic acquired brain injury participating in a community-based programme. Response-to-treatment was measured with two HRV resonance indices (low frequency activity [LF] and low frequency/high frequency ratio [LF/HF]). Main outcome: Behavior Rating Inventory of Executive Function-informant report (emotional control subscale [EC]). Results: Results show significant correlation between LF and EC with higher LF activity associated with greater emotional control; the association between LF/HF pre-post-change score and EC is not statistically significant. A moderation model, however, demonstrates a significant influence of attention …
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Voluntary upregulation of heart rate variability through biofeedback is improved by mental contemplative training.
Regulation of the parasympathetic nervous system, indexed through high frequency heart rate variability (HF-HRV), is indicative of physical and psychological health. However, little is known about the trainability of this capacity. We investigated the effects of a 9-month mental training program (the ReSource Project; n = 298) on voluntary HF-HRV upregulation, assessed with a novel biofeedback procedure. The program consisted of attentional, interoceptive, socio-affective and socio-cognitive training elements, all of which potentially influence parasympathetic regulation. Based on known links between oxytocin and parasympathetic activity, we also explored the relationship of HF-HRV upregulation to the oxytocin receptor system. We found that HF-HRV during the biofeedback session increased after 3 months of training, concomitant with prolonged respiration cycles. Breathing-controlled chang…
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Reducing Lethal Force Errors by Modulating Police Physiology.
Objectives: The aim of this study was to test an intervention modifying officer physiology to reduce lethal force errors and improve health.
Methods: A longitudinal, within-subjects intervention study was conducted with urban front-line police officers (n = 57). The physiological intervention applied an empirically validated method of enhancing parasympathetic engagement (ie, heart rate variability biofeedback) during stressful training that required lethal force decision-making.
Results: Significant post-intervention reductions in lethal force errors, and in the extent and duration of autonomic arousal, were maintained across 12 months. Results at 18 months begin to return to pre-intervention levels.
Conclusion: We provide objective evidence for a physiologically focused intervention in reducing errors in lethal force decision-making, improving health and safety for both police and the …
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Increased Cardiac Sympathetic Activity and Oxidative Stress in Habitual Electronic Cigarette Users: Implications for Cardiovascular Risk.
Importance: Electronic cigarettes (e-cigarettes) have gained unprecedented popularity, but virtually nothing is known about their cardiovascular risks.
Objective: To test the hypothesis that an imbalance of cardiac autonomic tone and increased systemic oxidative stress and inflammation are detectable in otherwise healthy humans who habitually use e-cigarettes.
Design, setting, and participants: Cross-sectional case-control study of habitual e-cigarette users and nonuser control individuals from 2015 to 2016 at the University of California, Los Angeles. Otherwise healthy habitual e-cigarette users between the ages of 21 and 45 years meeting study criteria, including no current tobacco cigarette smoking and no known health problems or prescription medications, were eligible for enrollment. Healthy volunteers meeting these inclusion criteria who were not e-cigarette users were eligible to b…
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Short-term heart rate variability--influence of gender and age in healthy subjects.
In the recent years, short-term heart rate variability (HRV) describing complex variations of beat-to-beat interval series that are mainly controlled by the autonomic nervous system (ANS) has been increasingly analyzed to assess the ANS activity in different diseases and under various conditions. In contrast to long-term HRV analysis, short-term investigations (<30 min) provide a test result almost immediately. Thus, short-term HRV analysis is suitable for ambulatory care, patient monitoring and all those applications where the result is urgently needed. In a previous study, we could show significant variations of 5-min HRV indices according to age in almost all domains (linear and nonlinear) in 1906 healthy subjects from the KORA S4 cohort. Based on the same group of subjects, general gender-related influences on HRV indices are to be determined in this study. Short-term 5-min HRV indic…
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Flexibility as the key for somatic health: From mind wandering to perseverative cognition.
Mind wandering (MW) has been defined as the brain's default mode of operation. It is a common experience, however, that this process can become maladaptive, and take the form of repetitive thoughts. We aimed to compare the cardiac and cognitive correlates of perseverative cognition (PC) and MW. Seventy-three healthy participants were engaged in two recall interviews designed to draw their attention to a neutral and a personally relevant negative episode. After each interview, participants performed a 20-min tracking task with thought probe while the electrocardiogram was continuously recorded. Perseverative cognition was associated with higher levels of cognitive inflexibility (slower reaction times, highest intrusiveness, efforts to inhibit), autonomic rigidity (low heart rate variability), and mood worsening compared to being focused on task or MW. Results suggest that MW fails to serv…
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Thought suppression, impaired regulation of urges, and Addiction-Stroop predict affect-modulated cue-reactivity among alcohol dependent adults.
Abstinent alcohol dependent individuals commonly employ thought suppression to cope with stress and intrusive cognitions about alcohol. This strategy may inadvertently bias attention towards alcohol-related stimuli while depleting neurocognitive resources needed to regulate urges, manifested as decreased heart rate variability (HRV) responsivity to alcohol cues. The present study tested the hypothesis that trait and state thought suppression, impaired regulation of urges, and alcohol attentional bias as measured by the Addiction-Stroop would have significant effects on the HRV responsivity of 58 adults in residential treatment for alcohol dependence (mean age=39.6 ± 9.4, 81% female) who participated in an affect-modulated cue-reactivity protocol. Regression analyses controlling for age, level of pre-treatment alcohol consumption, and baseline HRV indicated that higher levels of trait tho…
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Pop-Busui R, Evans GW, Gerstein HC, Fonseca V, Fleg JL, Hoogwerf BJ, Genuth S, Grimm RH, Corson MA, Prineas R, Action to Control Cardiovascular Risk in Diabetes Study Group (2010)MEDLINE-indexed journal, not yet read by usDiabetes care359 citations Effects of cardiac autonomic dysfunction on mortality risk in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.
Objective: Intensive therapy targeting normal blood glucose increased mortality compared with standard treatment in a randomized clinical trial of 10,251 participants with type 2 diabetes at high-risk for cardiovascular disease (CVD) events. We evaluated whether the presence of cardiac autonomic neuropathy (CAN) at baseline modified the effect of intensive compared with standard glycemia treatment on mortality outcomes in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial participants.
Research design and methods: CAN was assessed by measures of heart rate variability (HRV) and QT index (QTI) computed from 10-s resting electrocardiograms in 8,135 ACCORD trial participants with valid measurements (mean age 63.0 years, 40% women). Prespecified CAN definitions included a composite of the lowest quartile of HRV and highest QTI quartile in the presence or absence of peripher…
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