Differences In Autonomic Reactivity Research Articles

Topographic mapping of the sensorimotor qualities of empathic reactivity: A psychophysiological study in people with spinal cord injuries.

The experience of empathy for pain is underpinned by sensorimotor and affective dimensions which, although interconnected, are at least in part behaviorally and neurally distinct. Spinal cord injuries (SCI) induce a massive, below-lesion level, sensorimotor body-brain disconnection. This condition may make it possible to test whether sensorimotor deprivation alters specific dimensions of empathic reactivity to observed pain. To explore this issue, we asked SCI people with paraplegia and healthy controls to observe videos of painful or neutral stimuli administered to a hand (intact) or a foot (deafferented). The stimuli were displayed by means of a virtual reality set-up and seen from a first person (1PP) or third person (3PP) visual perspective. A number of measures were recorded ranging from explicit behaviors like explicit verbal reports on the videos, to implicit measures of muscular activity (like EMG from the corrugator and zygomatic muscles that may represent a proxy of sensorimotor empathy) and of autonomic reactivity (like the electrodermal response and Respiratory Sinus Arrhythmia that may represent a general proxy of affective empathy). While no across group differences in explicit verbal reports about the pain stimuli were found, SCI people exhibited reduced facial muscle reactivity to the stimuli applied to the foot (but not the hand) seen from the 1PP. Tellingly, the corrugator activity correlated with SCI participants' neuropathic pain. There were no across group differences in autonomic reactivity suggesting that SCI lesions may affect sensorimotor dimensions connected to empathy for pain.

The Added Value of Nonlinear Cardiorespiratory Coupling Indices in the Assessment of Depression.

The present study investigates the differences in autonomic nervous system (ANS) function and stress response between patients with major depressive disorder (MDD) and healthy subjects by measuring changes in ANS biomarkers. ANS-related parameters are derived from various biosignals during a mental stress protocol consisting of a basal, stress, and recovery phase. The feature set consists of ANS biomarkers such as the heart rate (HR) derived from the electrocardiogram, the respiratory rate derived from the respiration signal, vascular parameters obtained from a model-based photoplethysmographic pulse waveform analysis, and cardiorespiratory coupling indices derived from the joint analysis of the heart rate variability (HRV) and respiratory signals. In particular, linear cardiorespiratory interactions are quantified by means of time-frequency coherence, while interactions of quadratic nonlinear nature between HRV and respiration are quantified by means of real wavelet biphase. The intra-subject difference of a feature value between two phases of the protocol, the so-called autonomic reactivity, is considered as a ANS biomarker as well. The performance of ANS biomarkers on discriminating MDD patients is evaluated using a classification pipeline. The results show that the most discriminative ANS biomarkers are related with differences in HR and autonomic reactivity of both vascular and nonlinear cardiorespiratory coupling indices. Differences in autonomic reactivity imply that MDD and healthy subjects differ in their ability to cope with stress. Considering only HR and vascular characteristics a linear support-vector machine classifier yields to accuracy 72.5% and F1-score 73.2%. However, taking into account the nonlinear cardiorespiratory coupling indices, the classification performance improves, yielding to accuracy 77.5% and F1-score 78.0%.Clinical relevance- Changes in the nonlinear properties of the cardiorespiratory system during stress may yield additional information on the assessment of depression.

Photoplethysmographic Waveform Analysis for Autonomic Reactivity Assessment in Depression.

In the present study, a photoplethysmographic(PPG) waveform analysis for assessing differences in autonomic reactivity to mental stress between patients with Major Depressive Disorder(MDD) and healthy control(HC) subjects is presented. PPG recordings of 40MDD and 40HC subjects were acquired at basal conditions, during the execution of cognitive tasks, and at the post-task relaxation period. PPG pulses are decomposed into three waves (a main wave and two reflected waves) using a pulse decomposition analysis. Pulse waveform characteristics such as the time delay between the position of the main wave and reflected waves, the percentage of amplitude loss in the reflected waves, and the heart rate(HR) are calculated among others. The intra-subject difference of a feature value between two conditions is used as an index of autonomic reactivity. Statistically significant individual differences from stress to recovery were found for HR and the percentage of amplitude loss in the second reflected wave( A13) in both HC and MDD group. However, autonomic reactivity indices related to A13 reached higher values in HC than in MDD subjects(Cohen's[Formula: see text]), implying that the stress response in depressed patients is reduced. A statistically significant( ) negative correlation( r=-0.5) between depression severity scores and A13 was found. A decreased autonomic reactivity is associated with higher degree of depression. Stress response quantification by dynamic changes in PPG waveform morphology can be an aid for the diagnosis and monitoring of depression.

Inverse autonomic stress reactivity in depressed patients with and without prior history of depression

BackgroundThere is a considerable association between major depressive disorder (MDD) and cardiovascular disease, most possibly relying on abnormalities in the autonomic nervous system (ANS)-related cardiac reactivity, although the exact underlying pathophysiological pathway is unclear. This study tends to shed some additional light on this background by investigating ANS reactivity in MDD with respect to previous depression history through an objective stress challenge paradigm. MethodsThe study assessed the effects of an overnight hypothalamus-pituitary-adrenal (HPA) axis stimulation with metyrapone (MET) on baseline ANS activity through linear and non-linear heart rate variability (HRV) measures in the morning of two continuous days in a group of 14 physically healthy, antidepressant-free patients with clinical, non-psychotic MDD, to investigate differences in autonomic reactivity with respect to prior MDD history. ResultsThe main findings of this study include statistically significant time × group interactions with respect to several HRV measures, suggesting substantial differences on autonomic reactivity between patients with and without depression history. Hereby, recurrent-episode MDD patients showed lower vagal activity, while first-episode MDD patients increased PNS activity after HPA axis stimulation. ConclusionsThese findings indicate that HPA axis stimulation in MDD patients leads to inverse vagal response according to MDD history. We suggest that chronic stress system overactivation, as found in MDD, might lead to a progressive inversion of the original stress response through HPA axis and ANS divergence over the course of a recurrent illness. HRV could, thus, represent a significant biomarker in MDD with temporal sensitivity.

The psychophysiology of parenting: Individual differences in autonomic reactivity to positive and negative mood inductions and observed parental affect during dyadic interactions with children.

Parenting is a complex activity driven, in part, by parental emotional and physiological responses. However, work examining the physiological underpinnings of parenting behavior is still in its infancy, and very few studies have examined such processes beyond early childhood. The current study examines associations between Autonomic Nervous System (ANS) indices of parents' physiological reactivity to positive and negative mood states and observed parental affect during a series of discussion tasks with their adolescent child. Respiratory Sinus Arrhythmia (RSA) was measured as an index of parasympathetic nervous system (PNS) activation while viewing film clips designed to induce neutral, sad, and amused mood states. Parental positive affect, anger, and distress were observed during a series of parent-child discussion tasks, which included an ambiguous discussion regarding adolescent growth, a conflict discussion, and a fun-activity planning discussion. Results supported the association between aspects of parental physiological reactivity and observed affect during dyadic interactions. Further, RSA interacted with maternal depression to predict observed positive affect, anger, and distress, although differences across tasks and specific emotions were found regarding the nature of the interaction effects. Overall, results suggest that such neurobiological processes may be particularly important predictors of parental behavior, particularly in at-risk populations. (PsycINFO Database Record

Vagal tone as a biomarker of long-term memory for a stressful social event at 4 months.

This study investigates infants' memory for social stress after a 15-day retention interval using behavior and respiratory sinus arrhythmia (RSA). Experimental group infants were exposed to face-to-face still-face paradigm (FFSF) two times; the first time at 4 months and after a 2-week interval. Control group infants were exposed to FFSF only once at 4 months plus 2 weeks. Infants were categorized as suppressors or non-suppressors based on the direction of RSA change at first FFSF exposure. No behavioral differences were found among groups and exposure conditions. In the experimental group suppressors changed and showed no suppression when re-exposed 2 weeks later to FFSF. Non-suppressors showed no change in RSA from the first to the second exposure to FFSF. Control infants showed similar RSA changes to experimental infants at their first exposure. Findings indicate that 4-month-old infants have memory for social stress related to individual differences in autonomic reactivity.

Reduced Cardiac Vagal Modulation Impacts on Cognitive Performance in Chronic Fatigue Syndrome

BackgroundCognitive difficulties and autonomic dysfunction have been reported separately in patients with chronic fatigue syndrome (CFS). A role for heart rate variability (HRV) in cognitive flexibility has been demonstrated in healthy individuals, but this relationship has not as yet been examined in CFS. The objective of this study was to examine the relationship between HRV and cognitive performance in patients with CFS.MethodsParticipants were 30 patients with CFS and 40 healthy controls; the groups were matched for age, sex, education, body mass index, and hours of moderate exercise/week. Questionnaires were used to obtain relevant medical and demographic information, and assess current symptoms and functional impairment. Electrocardiograms, perceived fatigue/effort and performance data were recorded during cognitive tasks. Between–group differences in autonomic reactivity and associations with cognitive performance were analysed.ResultsPatients with CFS showed no deficits in performance accuracy, but were significantly slower than healthy controls. CFS was further characterized by low and unresponsive HRV; greater heart rate (HR) reactivity and prolonged HR-recovery after cognitive challenge. Fatigue levels, perceived effort and distress did not affect cognitive performance. HRV was consistently associated with performance indices and significantly predicted variance in cognitive outcomes.ConclusionsThese findings reveal for the first time an association between reduced cardiac vagal tone and cognitive impairment in CFS and confirm previous reports of diminished vagal activity.

Autonomic reactivity and clinical severity in children with sickle cell disease

Individual differences in autonomic nervous system reactivity have been studied in relation to physical and mental health outcomes, but rarely among children with chronic disease. The purpose of this study was to examine the associations among autonomic reactivity, clinical severity, family stressors, and mental health symptoms in children with homozygous sickle cell disease. Nineteen children with homozygous sickle cell disease participated in a cross-sectional study involving parent-completed measures, medical record reviews and laboratory-based measures of autonomic nervous system responses to social, cognitive, physical and emotional challenges. Autonomic reactivity was significantly associated with both clinical severity and externalizing behavior symptoms. Children with greater parasympathetic withdrawal during challenges compared to rest had significantly more severe disease (r = -0.45, p < 0.05); greater sympathetic activation during challenges compared to rest was associated with more externalizing behavior symptoms ( r= 0.44, p < 0.05). Children experiencing major family stressors had internalizing behavior symptoms but no difference in autonomic reactivity or clinical severity compared to children experiencing fewer family stressors. Individual differences in autonomic reactivity may offer a new, biologically plausible account for observed variation in painful episodes, other physical complications and behavioral symptoms among children with sickle cell disease.

Developmental and contextual influences on autonomic reactivity in young children.

Studies of cardiovascular reactivity in young children have generally employed integrated, physiologically complex measures, such as heart rate and blood pressure, which are subject to the multiple influences of factors such as blood volume, hematologic status, thermoregulation, and autonomic nervous system (ANS) tone. Reactivity studies in children have rarely employed more differentiated, proximal measures of autonomic function capable of discerning the independent effects of sympathetic and parasympathetic responses. We describe 1) the development, validity, and reliability of a psychobiology protocol assessing autonomic reactivity to challenge in 3- to 8-year-old children; 2) the influences of age, gender, and study context on autonomic measures; and 3) the distributions of reactivity measures in a normative sample of children and the prevalences of discrete autonomic profiles. Preejection period (PEP) and respiratory sinus arrythmia (RSA) were measured as indices of sympathetic and parasympathetic nervous system reactivity, respectively, and autonomic profiles were created to offer summative indices of PEP and RSA response. Results confirmed the protocol's validity and reliability, and showed differences in autonomic reactivity by age and study context, but not by gender. The studies' findings offer guidelines for future research on autonomic reactivity in middle childhood and support the feasibility of examining sympathetic and parasympathetic responses to challenge in 3- to 8-year-old children.

Are runners stoical? An examination of pain sensitivity in habitual runners and normally active controls

Anecdotal and clinical reports suggest that athletes are stoical. However, there are few studies comparing persons who exercise regularly with those who do not. This study compared two independent samples of regular runners and normally active controls, both without recent exercise, on cold pressor, cutaneous heat, and tourniquet ischemic pain tests. Results demonstrated that the runners' threshold for noxious cold was significantly higher than that of controls. The heart rate and blood pressure responses to cold were similar in the 2 groups, suggesting that differences in cold pain report did not result from differences in autonomic reactivity to cold. Signal detection theory measures demonstrated that runners discriminated among noxious thermal stimuli significantly better than controls, but neither noxious nor innocuous thermal report criteria differed between groups. The cohorts also did not differ in their report of ischemic pain sensations. Thus, these data do not generally support the hypothesis of pain insensitivity or stoicism in habitual runners. Rather, insensitivity occurs only in their response to noxious cold, which is suggested to be an adaptation to regular training.

Stress and physiological, behavioral and performance patterns of children under varied air ion levels

The possibility that individual differences in reactivity to stressors are a major factor underlying discordant results reported for air ion studies prompted an investigation of response patterns in school children under both normal indoor air ion levels and moderately increased negative air ion levels (4000±500/cm3). It was hypothesized that the impact of stressors is reduced with high negative air ionization, and that resultant changes in stress effects would be differentially exhibited according to the children's normal degree of stimulus reactivity. A counter-balanced, replicative, withinssubject design was selected, and the subjects were 12 environmentally sensitive, 1st–4th grade school children. In addition to monitoring stress effects on activity level, attention span, concentration to task and conceptual performance, measures were also made of urinary 5-hydroxyindole acetic acid levels and skin resistance response (SRR) to determine if changes extended to the physiological state. The cold water test was used to add physical stress and enable calculations of Lacey's autonomic lability scores (ALS) as indicators of individual reactivity. The results show main effects for air ions on both physiological parameters, with 48% less change in %SRR (P<0.01) and 46% less change in urinary 5-HIAA levels (P<0.055) during negative air ions, indicating increased stress tolerance. Strong interactive effects for ALS x air ion condition appeared, with high and low ALS children reacting oppositely to negative air ions in measures of skin resistance level (P<0.01), wrist activity (P<0.01) and digit span backwards (P<0.004). Thus individual differences in autonomic reactivity and the presence or absence of stressors appear as critical elements for internal validity, and in preventing consequent skewed results from obscuring progress in air ion research.

Getting individual differences in autonomic reactivity to work for instead of against you: determining the dominant "psychological" stress channel on the basis of a "biological" stress test.

ABSTRACTThe purpose of this study was to develop a procedure to increase the re liability of autonomic measures, such as skin conductance (SC) and heart rate (HR), when assessing negative emotional responding. The strategy was to capitalize on the individual difference factor by determining prior to the start of an experiment each subject's most reactive autonomic channel. To achieve this objective, a “biological” stress test (balloon‐burst test) was used. Subjects were then classified by using a median‐split, rank‐ordered procedure, as high SC responders, high HR responders. high responders in both channels, or low responders in both channels. The generality of the responder‐non‐responder classification was then assessed to a “psychological” stressor which involved presentations of a fear‐eliciting bodily‐injury slide. Transfer effects were obtained with those subjects defined as high responders on a given channel displaying greater reactivity on that channel when compared to subjects classified as low responders. The implications of these findings for clinical research were discussed.

Pupillometric studies of alcoholism.

Several parameters of the pupillary light and dark reflexes were employed as indices of sympathetic-parasympathetic activity in comparing alcoholics to nonalcoholics at rest, during stress, and following the termination of stress. Moreover, as the alcoholics were given the choice of drinking at frequent fixed intervals, the control values of autonomic activity were correlated with the subsequent decision to drink or not to drink. Overall differences in autonomic reactivity between nonalcoholics and alcoholics were found and drinkers were differentiable from alcoholic abstainers on several parameters.