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

Night time heart rate predicts next-day pain in fibromyalgia and primary back pain

Introduction

Primary chronic pain is pain that persists for over 3 months without associated measurable tissue damage. One of the most consistent findings in primary chronic pain is its association with autonomic hyperactivation. Yet whether the autonomic hyperactivation causes the pain or results from it is still unclear. It is also unclear to what extent autonomic hyperactivation is related to experienced pain intensity in different subtypes or primary chronic pain.

Objectives

Our first aim was to test lagged relationships between the markers of autonomic activation (heart rate) and pain intensity to determine its directionality. The main question here was whether autonomic biomarkers predict pain intensity or whether pain intensity predicts autonomic biomarkers. The second aim was to test whether this relationship is different between people with primary back pain and people with fibromyalgia.

Methods

Sixty-six patients with chronic pain were observed over an average of 81 days. Sleep heart rate and heart rate variability were measured with a wearable sensor, and pain intensity was assessed from daily subjective reports.

Results

The results showed a predictive relationship between sleep heart rate and next-day pain intensity (P < 0.05), but not between daily pain intensity and next night heart rate. There was no interaction with the type of chronic pain.

Conclusions

These findings suggest that autonomic hyperactivation, whether stress-driven or arising from other causes, precedes increases in primary chronic pain. Moreover, the present results suggest that autonomic hyperactivation is a common mechanism underlying the pain experience in fibromyalgia and chronic back pain.

Diurnal variation of cardiac autonomic activity in adolescent non-suicidal self-injury

Heart rate (HR) and vagally mediated heart rate variability (HRV) are two distinct biomarkers of cardiac autonomic activity. Decreased cardiac vagal activity (or decreased HRV) in particular has been linked with impairments in the functional flexibility of the central autonomic network (CAN), resulting in impaired stress and emotion regulatory capacities. Decreased HRV is widely used as trait marker of psychopathology. Repetitive engagement in non-suicidal self-injury (NSSI) in adolescence correlates with both deficits in stress and emotion regulation, as well as decreased HRV. Existing research has, however, focused on short-term recordings of HR and HRV under resting and phasic conditions. In this study, we examined whether diurnal variation of cardiac autonomic activity, indexed by cosinor parameters of HR and HRV derived from 48 h of ambulatory ECG recording under natural conditions over a weekend, are altered in female adolescents with NSSI disorder compared to controls (HC; N = 30 per study group). Several important confounds, including physical activity, were controlled for. Female adolescents with NSSI show higher rhythm-adjusted 24 h mean levels and greater respective amplitude of HR, as well as lower rhythm-adjusted 24 h mean levels and smaller respective amplitude of HRV. Peak levels in both HR and HRV in the NSSI group were reached approximately 1 h later compared to HC. Severity of exposure to early life maltreatment might be linked with altered amplitudes of 24 h HR and HRV. Diurnal rhythms of cardiac autonomic activity might hold promise as objective indicators of disordered stress and emotion regulation in developmental psychopathology, and as such should be investigated in future studies with rigorous assessment and control of potential confounds.

The cardiac correlates of feeling safe in everyday life: A Bayesian replication study

BACKGROUND

Feeling safe and secure has been proposed to dampen autonomic arousal and buffer threat responses. In a previous study, we could show that momentary ratings of subjective safety were associated with elevated heart rate variability (specifically, root mean square of successive differences; RMSSD) and lower heart rate in everyday life, thus suggesting a health-protective role of feeling safe.

METHODS

This study aimed to replicate this effect in a sample of N = 79 adults, applying Bayesian statistics with prior effects of the original study.

RESULTS

Using an ecological momentary assessment (EMA) across three days we could replicate the effect of lower heart rate and higher RMSSD in moments when participants felt more safe. In accordance with the original study, we could also show that the effect on heart rate were independent of RMSSD, thus suggesting a contribution of sympathetic activity to this effect.

CONCLUSION

The findings confirm the connection between momentary feelings of safety and cardiac regulation, thus substantiating research on the health-protective role of psychological safety.

Autonomic complexity dynamically indexes affect regulation in everyday life

Affect regulation often is disrupted in depression. Understanding biomarkers of affect regulation in ecologically valid contexts is critical for identifying moments when interventions can be delivered to improve regulation and may have utility for identifying which individuals are vulnerable to psychopathology. Autonomic complexity, which includes linear and nonlinear indices of heart rate variability, has been proposed as a novel marker of neurovisceral integration. However, it is not clear how autonomic complexity tracks with regulation in everyday life, and whether low complexity serves as a marker of related psychopathology. To measure regulation phenotypes with diminished influence of current symptoms, 37 young adults with remitted major depressive disorder (rMDD) and 28 healthy comparisons (HCs) completed ambulatory assessments of autonomic complexity and affect regulation across one week in everyday life. Multilevel models indicated that in HCs, but not rMDD, autonomic complexity fluctuated in response to regulation cues, increasing in response to reappraisal and distraction and decreasing in response to negative affect. Higher complexity across the week predicted greater everyday regulation success, whereas greater variability of complexity predicted lower (and less variable) negative affect, rumination, and mind-wandering. Results suggest that ambulatory assessment of autonomic complexity can passively index dynamic aspects of real-world affect and regulation, and that dynamic physiological reactivity to regulation is restricted in rMDD. These results demonstrate how intensive sampling of dynamic, nonlinear regulatory processes can advance our understanding of potential mechanisms underlying psychopathology. Such measurements might inform how to test interventions to enhance neurovisceral complexity and affect regulation success in real time. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Discovery of associative patterns between workplace sound level and physiological wellbeing using wearable devices and empirical Bayes modeling

We conducted a field study using multiple wearable devices on 231 federal office workers to assess the impact of the indoor environment on individual wellbeing. Past research has established that the workplace environment is closely tied to an individual's wellbeing. Since sound is the most-reported environmental factor causing stress and discomfort, we focus on quantifying its association with physiological wellbeing. Physiological wellbeing is represented as a latent variable in an empirical Bayes model with heart rate variability measures-SDNN and normalized-HF as the observed outcomes and with exogenous factors including sound level as inputs. We find that an individual's physiological wellbeing is optimal when sound level in the workplace is at 50 dBA. At lower (<50dBA) and higher (>50dBA) amplitude ranges, a 10 dBA increase in sound level is related to a 5.4% increase and 1.9% decrease in physiological wellbeing respectively. Age, body-mass-index, high blood pressure, anxiety, and computer use intensive work are person-level factors contributing to heterogeneity in the sound-wellbeing association.

Practices and Applications of Heart Rate Variability Monitoring in Endurance Athletes

Heart rate variability reflects fluctuations in the changes in consecutive heartbeats, providing insight into cardiac autonomic function and overall physiological state. Endurance athletes typically demonstrate better cardiac autonomic function than non-athletes, with lower resting heart rates and greater variability. The availability and use of heart rate variability metrics has increased in the broader population and may be particularly useful to endurance athletes. The purpose of this review is to characterize current practices and applications of heart rate variability analysis in endurance athletes. Important considerations for heart rate variability analysis will be discussed, including analysis techniques, monitoring tools, the importance of stationarity of data, body position, timing and duration of the recording window, average heart rate, and sex and age differences. Key factors affecting resting heart rate variability will be discussed, including exercise intensity, duration, modality, overall training load, and lifestyle factors. Training applications will be explored, including heart rate variability-guided training and the identification and monitoring of maladaptive states such as overtraining. Lastly, we will examine some alternative uses of heart rate variability, including during exercise, post-exercise, and for physiological forecasting and predicting performance.

Anxiety in a regular day of work: A 24 hour psychophysiological investigation in young dentists with gender comparison

Introduction and aim

Dentistry is a highly demanding profession with a strong mental and physical involvement, possibly generating anxiety. Very few studies assessed psychophysiological activity in dentists, while none tried to relate it with gender during a routine working day. This study aims at evaluating correlations between gender, psychophysiological indexes, and psychological variables.

Materials and methods

Data were acquired at the Dental Clinic of the University of Padua on 20 healthy young dentists (10 M-10F) during a 24 h period of a working day. Physiological variables (measured with E4 Empatica) were electrodermal activity (EDA), heart rate variability (HRV) and heart rate (HR). Participants anxiety was measured through a self-reported scale on patient-relationship anxiety and through the Generalized Anxiety Disorder-7 Questionnaire (GAD-7).

Results

5 (3F, 2 M) participants over 20 had a GAD-7 score ≥ 10. Female gender, in comparison to Male, was associated with higher perceived patient relationship anxiety (p = 0.002) and lower HRV (p-adj = 0.022). The gender Male, although being associated with lower level of self-reported anxiety (p = 0.002), showed an equal number of subjects with a GAD-7 score ≥ 10 (p = 0.371). No interaction between gender and EDA was found, nor an effect of GAD score on EDA, HRV and HR values. Higher values of EDA were found during sleep time; a difference between sleep time and working time EDA (p = 0.037) and a difference between sleep time and daytime (p = 0.0045). A different HR between sleep and all daytime (p < 0.001) was also highlighted.

Conclusion

25% of dentists fell within generalized anxiety disorder diagnosis, compared to a maximum of 8.6% in the general population. A possible general biomarker of excessive stress response was measured: a shift of circadian sympathetic activity was found in dentists; a higher activity during sleep in comparison to working time and daytime. The Female gender was associated with higher perceived patient-approach anxiety, lower parasympathetic activity, and a comparable sympathetic activity to the Male gender, thus fostering a possible vulnerability to excessive stress. This study underlines the need to empower the psychological approach to stress and patient-relationship in dentistry.

Physiological reactions to acute stressors and subjective stress during daily life: A systematic review on ecological momentary assessment (EMA) studies

Objective

This review aims to provide an overview of ecological momentary assessment (EMA) studies analyzing stress reactivity during daily life in terms of direct and moderated influence of acute stress on physiological responses.

Materials and methods

A systematic literature search was performed on November 29, 2021 using Web of Science, MEDLINE and PsycINFO to identify prospective EMA studies targeting acute stressors or stress under naturalistic conditions, without restrictions of publication date or population. Study quality was assessed for multiple EMA-specific sources of bias.

Results

Out of 4285 non-duplicate records, 107 publications involving 104 unique studies were included. The majority of studies assessed acute physiological stress responses primarily through salivary cortisol (n = 59) and cardiovascular outcomes (n = 32). Most studies performed at least three measurements per day (n = 59), and had a moderate risk of recall bias (n = 68) and confounding (n = 85). Fifty-four studies reported a compliance of ≥80%. Direct, non-moderated positive associations were observed between acute stress exposure and concurrent cortisol levels (44%, n = 11/25), systolic (44%, 8/18) and diastolic blood pressure (53%, 8/15) and heart rate (53%, 9/17). Several inter- and intra-individual moderators were identified, such as age, gender, health status, chronic stress, work-related resources, physical activity and stress coping indicators.

Conclusions

About half of the reviewed EMA studies demonstrated direct associations between everyday acute stress exposure and physiological responses, including increased cortisol levels, blood pressure and heart rate. Results further suggested various moderator variables that could help develop tailored prevention strategies and identify groups at higher risk for dysfunctional stress responses.

Registration

PROSPERO—Reg.-No.: PROSPERO 2020 CRD42020163178.

Not self-aware? Psychological antecedents and consequences of alienating from one’s actual motives, emotions, and goals

Philosophers and scientists have been puzzling over the potential antecedents and consequences of self-awareness or its relative absence since time immemorial. One major reason is the difficulty of identifying individuals’ actual needs, emotions, or goals and thus making statements about their level of self-awareness. Drawing on a “duality of mind” approach, we review our research that quantified discrepancies between first-person perspective and third-person perspective assessments of motives (“needs”), emotions, and goals as indicators of relative self-awareness. Also, we expand on their proximal causes related to personality–situation interactions and their emotional and motivational consequences. We discuss similarities among the three branches of research on motives, emotions, and goals and, lastly, provide an outlook for future research.

Feelings from the Heart Part II: Simulation and Validation of Static and Dynamic HRV Decrease-Trigger Algorithms to Detect Stress in Firefighters

Several mobile devices have multiple sensors on board and interact with smartphones. This allows for a complex online evaluation of physiological data, important for interactive psychophysiological assessments, which targets the triggering of psychological states based on physiological data such as heart rate variability (HRV). However, algorithms designed to trigger meaningful physiological processes are rare. One exception is the concept of additional HRV reduction (AddHRVr), which aims to control for metabolic-related changes in cardiac activity. In this study we present an approach, based on data of a previous study, which allows algorithm settings to be derived that could be used to automatically trigger the assessment of psychosocial states by online-analysis of transient HRV changes in a sample of 38 firefighters. Settings of a static and a dynamic AddHRVr algorithm were systematically manipulated and quantified by binary triggers. These triggers were subjected to multilevel models predicting increases of objective stress during a period of 24 h. Effect estimates (i.e., odds) and bootstrap power simulations were calculated to inform about the most robust algorithm settings. This study delivers evidence that a dynamic AddHRVr algorithm can trigger transitions of stress, which should be further validated in future interactive psychophysiological assessments.

How and Why Could Smiling Influence Physical Health? A Conceptual Review

Smiling has been a topic of interest to psychologists for decades, with a myriad of studies tying this behavior to well-being. Despite this, we know surprisingly little about the nature of the connections between smiling and physical health. We review the literature connecting both naturally occurring smiles and experimentally manipulated smiles to physical health and health-relevant outcomes. This work is discussed in the context of existing affect and health-relevant theoretical models that help explain the connection between smiling and physical health including the facial feedback hypothesis, the undoing hypothesis, the generalized unsafety theory of stress, and polyvagal theory. We also describe a number of plausible pathways, some new and relatively untested, through which smiling may influence physical health such as trait or state positive affect, social relationships, stress buffering, and the oculocardiac reflex. Finally, we provide a discussion of possible future directions, including the importance of cultural variation and replication. Although this field is still in its infancy, the findings from both naturally occurring smile studies and experimentally manipulated smile studies consistently suggest that smiling may have a number of health-relevant benefits including beneficially impacting our physiology during acute stress, improved stress recovery, and reduced illness over time.

Effects of an incremental theory of the personality intervention on psychophysiological responses to social stress during the transition to college

This randomized controlled trial (NCT04786496) examined the effects of a preventive intervention based on Incremental Theory of the Personality (ITP) on psychophysiological responses to social stress and evaluated whether levels of depression moderate the intervention effects. The participants, 107 first-year university students, were randomly assigned to one of three conditions: ITP intervention, ITP + a self-affirmation intervention (SA), and a control condition (CC). Indicators of the Hypothalamic–Pituitary–Adrenal axis, autonomic nervous system, and subjective mood were assessed with the Trier Social Stress Task. Participants in the ITP condition displayed a lower decline in respiratory sinus arrythmia (RSA) compared to those in the CC during the first phases of the task [Slopes: -0.08 (0.09) vs -0.21 (0.09), z = 2.86, p = .004] and a higher decrease in cortisol at recovery [β = -0.18 (0.08), z = -2.37, p = .018]. Depressive symptoms moderated the effect of ITP [β = -0.10 (0.05), z = -2.15, p =.032] and ITP+SA [β = -0.09 (0.04), z = -2.06, p =.039] in the decline during stress and recovery in RSA. In participants with low/medium levels of depressive symptoms, both interventions predicted a lower decline during stress [Slopes: -0.06 (0.09) for ITP, -0.17 (.09) for ITP+SA, and -0.26 (0.09) for CC] and higher recovery in RSA [Slopes: 0.18 (0.01) for ITP, 0.24 (0.01) for ITP+SA, and 0.30 (0.01) for CC]. The findings suggest that the ITP intervention has the potential to be an effective preventive intervention to reduce the stress response.

Evaluating commercially available wireless cardiovascular monitors for measuring and transmitting real-time physiological responses in children with autism

Commercially available wearable biosensors have the potential to enhance psychophysiology research and digital health technologies for autism by enabling stress or arousal monitoring in naturalistic settings. However, such monitors may not be comfortable for children with autism due to sensory sensitivities. To determine the feasibility of wearable technology in children with autism age 8-12 years, we first selected six consumer-grade wireless cardiovascular monitors and tested them during rest and movement conditions in 23 typically developing adults. Subsequently, the best performing monitors (based on data quality robustness statistics), Polar and Mio Fuse, were evaluated in 32 children with autism and 23 typically developing children during a 2-h session, including rest and mild stress-inducing tasks. Cardiovascular data were recorded simultaneously across monitors using custom software. We administered the Comfort Rating Scales to children. Although the Polar monitor was less comfortable for children with autism than typically developing children, absolute scores demonstrated that, on average, all children found each monitor comfortable. For most children, data from the Mio Fuse (96%-100%) and Polar (83%-96%) passed quality thresholds of data robustness. Moreover, in the stress relative to rest condition, heart rate increased for the Polar, F(1,53) = 135.70, p < 0.001, ηp²  = 0.78, and Mio Fuse, F(1,53) = 71.98, p < 0.001, ηp²  = 0.61, respectively, and heart rate variability decreased for the Polar, F(1,53) = 13.41, p = 0.001, ηp²  = 0.26, and Mio Fuse, F(1,53) = 8.89, p = 0.005, ηp²  = 0.16, respectively. This feasibility study suggests that select consumer-grade wearable cardiovascular monitors can be used with children with autism and may be a promising means for tracking physiological stress or arousal responses in community settings. LAY SUMMARY: Commercially available heart rate trackers have the potential to advance stress research with individuals with autism. Due to sensory sensitivities common in autism, their comfort wearing such trackers is vital to gathering robust and valid data. After assessing six trackers with typically developing adults, we tested the best trackers (based on data quality) in typically developing children and children with autism and found that two of them met criteria for comfort, robustness, and validity.

Levels of Emotional Awareness: Theory and Measurement of a Socio-Emotional Skill

Emotional awareness is the ability to conceptualize and describe one's own emotions and those of others. Over thirty years ago, a cognitive-developmental theory of emotional awareness patterned after Piaget's theory of cognitive development was created as well as a performance measure of this ability called the Levels of Emotional Awareness Scale (LEAS). Since then, a large number of studies have been completed in healthy volunteers and clinical populations including those with mental health or systemic medical disorders. Along the way, there have also been further refinements and adaptations of the LEAS such as the creation of a digital version in addition to further advances in the theory itself. This review aims to provide a comprehensive summary of the evolving theoretical background, measurement methods, and empirical findings with the LEAS. The LEAS is a reliable and valid measure of emotional awareness. Evidence suggests that emotional awareness facilitates better emotion self-regulation, better ability to navigate complex social situations and enjoy relationships, and better physical and mental health. This is a relatively new but promising area of research in the domain of socio-emotional skills. The paper concludes with some recommendations for future research.

Mind-Body and Psychosocial Interventions May Similarly Affect Heart Rate Variability Patterns in Cancer Recovery: Implications for a Mechanism of Symptom Improvement

Background:

Advancements in early detection and treatment of cancer have led to increased survival rates and greater need to identify effective supportive care options for resolving symptoms of survivorship. Many non-pharmacological approaches to symptom management during and after cancer treatment involve emotional self-regulation as a central strategy for improving well-being. Identifying commonalities among these strategies’ mechanisms of action may facilitate understanding of what might be useful for optimizing intervention effects. Heart rate variability (HRV) parameters are indicative of improved autonomic nervous system (ANS) balance and resiliency and reduced emotional distress and are thus identified as a mechanism to discuss as a marker of potential for intervention efficacy and a target for optimization.

Methods:

HRV data from 2 studies, 1 examining a mind-body intervention and 1 examining a psychosocial intervention, are presented as a point of discussion about preliminary associations between the interventions, change in HRV, and emotional distress reduction.

Results:

HRV significantly decreased in sympathetic activity in response to a mind-body intervention (Qigong/Tai Chi), and increased vagal tone in response to a psychosocial (storytelling) intervention. In both, these changes in HRV parameters were associated with improved emotional states.

Conclusion:

Our preliminary data suggest that HRV may serve as an important marker of underlying changes that mediate emotional regulation; this observation deserves further investigation. If identified as a worthy target, focusing on interventions that improve HRV within the context of interventions for cancer patients may be important to key outcomes and clinical practice.

Feelings from the heart: Developing HRV decrease-trigger algorithms via multilevel hyperplane simulation to detect psychosocially meaningful episodes in everyday life

Heart rate variability (HRV) has been associated with diverse psychosocial concepts, like stress, anxiety, depression, rumination, social support, and positive affect, among others. Although recent ecological momentary assessment research devoted the analysis of cardiac‐psychosocial interactions in daily life, traditional time sampling designs are compromised by a random pairing of cardiac and psychosocial variables across several time points. In this study, we present an approach based on the concept of additional heart rate and additional HRV reductions, which aims to control for metabolic‐related changes in cardiac activity. This approach allows derivation of algorithm settings, which can later be used to automatically trigger the assessment of psychosocial states by online‐analysis of transient HRV changes. We used an already published data set in order to identify potential triggers offline indexing meaningful HRV decrements as related to low quality social interactions. First, two algorithm settings for a non‐metabolic HRV decrease trigger (i.e., the number of HRV decreases in a specified time window) were systematically manipulated and quantified by binary triggers (HRV decrease detected vs. not). Second, triggers were then entered in multilevel models predicting (lower levels of) social support. Effect estimates and bootstrap power simulations were visualized on hyperplanes to determine the most robust algorithm settings. A setting associated with 13 HRV decreases out of 29 min seems to be particularly sensitive to low quality of social interactions. Further algorithm refinements and validation studies are encouraged.

We demonstrate a simulation‐based approach to derive algorithms for an interactive psychophysiological assessment, which aims to detect transient decrements in heart rate variability (HRV) in everyday life. The suggested methodological approach could be applied to various ecological momentary assessment data sets with parallel recording of HRV and psychosocial variables.

Effects of Heat Stress on Heart Rate Variability in Free-Moving Sheep and Goats Assessed With Correction for Physical Activity

Heart rate variability (HRV) is the heart beat-to-beat variation under control of the cardiovascular function of animals. Under stressed conditions, cardiac activity is generally regulated with an upregulated sympathetic tone and withdrawal of vagal tone; thus, HRV monitoring can be a non-invasive technique to assess stress level in animals especially related to animal welfare. Among several stress-induced factors, heat stress is one of the most serious causes of physiological damage to animals. The aim of this study was to assess the effects of heat stress on HRV in small ruminants under free-moving conditions. In three experimental periods (June, August, and October), inter-beat intervals in sheep and goats (three for each) in two consecutive days were measured. HRV parameters were calculated from the inter-beat interval data by three types of analyses: time domain, frequency domain, and non-linear analyses. The temperature–humidity index (THI) was used as an indicator of heat stress, and vectorial dynamic body acceleration (VeDBA) was calculated to quantify the physical activity of the animals tested. First, we investigated correlations of THI and VeDBA with HRV parameters; subsequently, THI was divided into five categories according to the values obtained (≤ 65, 65–70, 70–75, 75–80, and >80), and the effects of the THI categories on HRV parameters were investigated with and without correcting for the effects of physical activity based on the VeDBA. The results indicated that HRV significantly decreased with increasing THI and VeDBA. For non-linear HRV parameters that were corrected for the effects of physical activity, it was suggested that there would be a threshold of THI around 80 that strongly affected HRV; high heat stress can affect the autonomic balance of animals non-linearly by inducing the sympathetic nervous system. In conclusion, to assess psychophysiological conditions of unrestrained animals by HRV analysis, the confounding effect of physical activity on HRV should be minimized for a more precise interpretation of the results.

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. All of these methods use a subset of 24 h worth of HRV and movement data to do so: either the first 10 min of every hour, the full 24 h, a combination of 10 min from three consecutive hours, a classification of level of movement, the data from day n to detect episodes in day n + 1, or a range of activities during lab calibration. The method that used the full 24 h worth of data detected the largest percentage of episodes of reduced additional HRV that matched with self-reported stress levels, making this method the most promising, while using the first 10 min from three consecutive hours was a good runner-up.

Affective agnosia: a core affective processing deficit in the alexithymia spectrum

Affective agnosia, an impairment in knowing how one feels emotionally, has been described as an extreme deficit in the experience and expression of emotion that may confer heightened risk for adverse medical outcomes. Alexithymia, by contrast, has been proposed as an over-arching construct that includes a spectrum of deficits of varying severity, including affective agnosia at the more severe end. This perspective has been challenged by Taylor and colleagues, who argue that the concept of affective agnosia is unnecessary. We compare these two perspectives by highlighting areas of agreement, reasons for asserting the importance of the affective agnosia concept, errors in Taylor and colleagues’ critique, and measurement issues. The need for performance-based measures of the ability to mentally represent emotional states in addition to metacognitive measures is emphasized. We then draw on a previously proposed three-process model of emotional awareness that distinguishes affective response generation, conceptualization and cognitive control processes which interact to produce a variety of emotional awareness and alexithymia phenotypes - including affective agnosia. The tools for measuring these three processes, their neural substrates, the mechanisms of brain-body interactions that confer heightened risk for adverse medical outcomes, and the differential treatment implications for different kinds of deficits are described. By conceptualizing alexithymia as a spectrum of deficits, the opportunity to match specific deficit mechanisms with personalized treatment for patients will be enhanced.

Toward Emotion Recognition From Physiological Signals in the Wild: Approaching the Methodological Issues in Real-Life Data Collection

Emotion, mood, and stress recognition (EMSR) has been studied in laboratory settings for decades. In particular, physiological signals are widely used to detect and classify affective states in lab conditions. However, physiological reactions to emotional stimuli have been found to differ in laboratory and natural settings. Thanks to recent technological progress (e.g., in wearables) the creation of EMSR systems for a large number of consumers during their everyday activities is increasingly possible. Therefore, datasets created in the wild are needed to insure the validity and the exploitability of EMSR models for real-life applications. In this paper, we initially present common techniques used in laboratory settings to induce emotions for the purpose of physiological dataset creation. Next, advantages and challenges of data collection in the wild are discussed. To assess the applicability of existing datasets to real-life applications, we propose a set of categories to guide and compare at a glance different methodologies used by researchers to collect such data. For this purpose, we also introduce a visual tool called Graphical Assessment of Real-life Application-Focused Emotional Dataset (GARAFED). In the last part of the paper, we apply the proposed tool to compare existing physiological datasets for EMSR in the wild and to show possible improvements and future directions of research. We wish for this paper and GARAFED to be used as guidelines for researchers and developers who aim at collecting affect-related data for real-life EMSR-based applications.

Does Cardiorespiratory Fitness Buffer Stress Reactivity and Stress Recovery in Police Officers? A Real-Life Study

High levels of cardiorespiratory fitness have the potential to buffer against physical and mental health impairments, which can result from exposure to occupational stress. Police officers are especially at risk of high psychosocial stress; therefore, effective intervention strategies are warranted. Given this background, the purpose of the present study was to examine whether police officers with different levels of cardiorespiratory fitness differ with regard to their (a) physiological stress reactivity during acute real-life stress situations, and (b) physiological recovery related to acute and chronic work stress. In total, 201 police officers took part in this study (M = 38.6 years, SD = 10.1, 35.8% females). Officers were contacted eight times on a smartphone during their workday, and asked to report their current level of positive and negative affect, as well as feelings of stress and anger. Physiological stress responses and recovery (heart rate variability) were assessed using Movisens EcgMove3 devices. The Åstrand bicycle ergometer test was used to assess participants' cardiorespiratory fitness. Chronic work stress was assessed using the effort-reward imbalance model and the job strain model. Multilevel modeling was used to test buffering effects of cardiorespiratory fitness on physiological stress reactivity. Linear regression was applied to test stress-buffering effects of cardiorespiratory fitness on physiological recovery. Results showed lowered physiological stress reactivity to acute work stress in officers with higher levels of cardiorespiratory fitness. However, these results were not consistent, with no effects occurring for feelings of anger, positive affect, and negative affect. Chronic work stress (effort-reward imbalance) was related to lower physiological recovery. Cardiorespiratory fitness was positively related to physiological recovery. Data did not support interactions between work stress and cardiorespiratory fitness on physiological recovery. To some extent, cardiorespiratory fitness seems to have the potential to buffer stress reactivity in police officers in acute stress situations. Therefore, we encourage promoting fitness programs which aim to enhance cardiorespiratory fitness in stressful occupations such as law enforcement. Improvements in cardiorespiratory fitness might further enhance physiological recovery from chronic work stress, which is thought to improve cardiovascular health.

The Effect of the Menstrual Cycle on Daily Measures of Heart Rate Variability in Athletic Women

Abstract. Heart rate variability (HRV) is a biomarker used to reflect both healthy and pathological state(s). The effect of the menstrual cycle and menstrual cycle phases (follicular, luteal) on HRV remains unclear. Active eumenorrheic women free from exogenous hormones completed five consecutive weeks of daily, oral basal body temperature (BBT) and HRV measurements upon waking. Descriptive statistics were used to characterize shifts in the HRV measures: standard deviation of NN intervals (SDNN), root mean square of successive difference (rMSSD), high (HF) and low frequency (LF) across the menstrual cycle and between phases. All HRV measures were assessed by medians ( Mdn), median difference of consecutive days ( Mdn∆) and variance. Seven participants ( M ±  SD; age: 28.60 ± 8.40 year) completed the study with regular menstrual cycles (28.40 ± 2.30 days; ovulation day 14.57 ± 0.98 day). Median rMSSD displayed a nonlinear decrease across the menstrual cycle and plateau around the day of ovulation. A negative shift before ovulation in Mdn∆, rMSSD, SDNN, and LF as well as peak on luteal phase Day 4 in rMSSD and SDNN was observed. Median variance increased in rMSSD (150.06 ms2) SDNN (271.12 ms2), and LF variance (0.001 sec2/Hz) from follicular to luteal phase. Daily HRV associated with the parasympathetic nervous system was observed to decrease nonlinearly across the menstrual cycle.

Stress and Depressive Symptoms Among Demographically Diverse American Pregnant Women

Pregnancy is a sensitive period of life where mental health is of utmost importance to the mother's and child's well-being peripartum and beyond. To better prevent and treat common mental health conditions such as depressive symptoms and perceived stress (defined in this study to encompass psychological and physiological (heart rate variability (HRV)) dimensions), it is crucial to examine and report differences in mental health outcomes among demographically diverse pregnant women. Therefore, the purpose of this secondary analysis (N = 79) was to determine if there are differences in mental health outcomes between pregnant women who differ across demographic factors, as well as to determine if demographic factors predict mental health outcomes when controlling for other demographic variables. Findings indicate that there were significant differences in depressive symptoms and perceived stress by all demographic factors except age. Marital status and total household income were the only significant predictors of depressive symptoms and perceived stress, respectively, when all other factors were controlled. There were no significant differences or correlations between demographic variables and HRV. Pregnant women may be predisposed to adverse mental health outcomes, illustrating the need for more refined interventions that are sensitive to pre-existing factors.

Using ambulatory assessment to measure dynamic risk processes in affective disorders

BACKGROUND

Rapid advances in the capability and affordability of digital technology have begun to allow for the intensive monitoring of psychological and physiological processes associated with affective disorders in daily life. This technology may enable researchers to overcome some limitations of traditional methods for studying risk in affective disorders, which often (implicitly) assume that risk factors are distal and static - that they do not change over time. In contrast, ambulatory assessment (AA) is particularly suited to measure dynamic "real-world" processes and to detect fluctuations in proximal risk for outcomes of interest.

METHOD

We highlight key questions about proximal and distal risk for affective disorders that AA methods (with multilevel modeling, or fully-idiographic methods) allow researchers to evaluate.

RESULTS

Key questions include between-subject questions to understand who is at risk (e.g., are people with more affective instability at greater risk than others?) and within-subject questions to understand when risk is most acute among those who are at risk (e.g., does suicidal ideation increase when people show more sympathetic activation than usual?). We discuss practical study design and analytic strategy considerations for evaluating questions of risk in context, and the benefits and limitations of self-reported vs. passively-collected AA.

LIMITATIONS

Measurements may only be as accurate as the observation period is representative of individuals' usual life contexts. Active measurement techniques are limited by the ability and willingness to self-report.

CONCLUSIONS

We conclude by discussing how monitoring proximal risk with AA may be leveraged for translation into personalized, real-time interventions to reduce risk.

The Association Between Juvenile Onset of Depression and Emotion Regulation Difficulties

Juvenile onset of Major Depressive Disorder (MDD) is associated with increased likelihood of recurrent episodes of depression and more detrimental clinical trajectories. The aim of the current study was to investigate the effect of juvenile onset of MDD on emotion regulation as measured by self-report and Heart Rate Variability (HRV). Furthermore, we wanted to assess whether juvenile onset impacted the association between rumination and depressive symptoms. Sixty-four individuals with at least three prior episodes of MDD were recruited and filled out self-report questionnaires measuring rumination and emotion regulation abilities. In addition, electrocardiographic assessments were used to calculate HRV. Based on self-reported age of MDD onset, individuals were divided in two groups: Juvenile onset of MDD (first MDD episode before the age of 18, n = 30) and adult onset of MDD (first MDD episode after the age of 18, n = 34). Results showed that individuals whose first depressive episode occurred in childhood and adolescence reported more rumination and less emotional clarity compared to individuals who had their first episode of MDD in adulthood. Moreover, the tendency to ruminate was strongly associated with depressive symptoms in the juvenile onset of MDD group, whereas no such association was found in the adult onset group. There was no significant group difference for HRV. The findings are discussed in light of existing literature, in addition to suggesting how our findings may inform clinical practice and future research. We conclude that juvenile onset of MDD may lead to difficulties in emotion regulation and that these difficulties may increase depressive symptoms and vulnerability for relapse in this particular subgroup.

Higher Emotional Awareness Is Associated With Reduced Pain in Irritable Bowel Syndrome Patients: Preliminary Results

OBJECTIVE

Recent evidence indicates that interventions designed to improve emotional awareness reduce pain in irritable bowel syndrome. This preliminary study sought to determine whether trait emotional awareness is associated with typical pain in patients with irritable bowel syndrome.

METHODS

Healthy volunteers (n = 66) and irritable bowel syndrome patients (n = 50) were asked to self-report their typical levels of pain intensity and complete both the Levels of Emotional Awareness Scale and the Somatization Scale of the Brief Symptom Inventory.

RESULTS

Levels of Emotional Awareness Scale scores in irritable bowel syndrome patients did not differ from scores in healthy participants; however, higher Levels of Emotional Awareness Scale scores in irritable bowel syndrome patients predicted lower levels of typical pain intensity (r(45) = -.36, p = .01, 95% CI [-.59, -.08]) and lower levels of somatization (r(45)= -.31, p = .03, 95% CI [-.55, -.02]).

CONCLUSIONS

This inverse relationship between emotional awareness and both pain and somatization symptoms is consistent with evidence that irritable bowel syndrome patients experience reduced pain from therapies designed to improve emotional awareness. The Levels of Emotional Awareness Scale could potentially be used to identify patients who could benefit from such therapy and could potentially be a moderator of response to efficacious psychological therapies.

Heart rate variability during a cognitive reappraisal task in female patients with borderline personality disorder: the role of comorbid posttraumatic stress disorder and dissociation

BACKGROUND

Emotion dysregulation is a core feature of borderline personality disorder (BPD), which often co-occurs with posttraumatic stress disorder (PTSD). Difficulties in emotion regulation (ER) have been linked to lower high-frequency heart rate variability (HF-HRV), a measure of autonomous nervous system functioning. However, previous research on vagally-mediated heart rate in BPD revealed heterogeneous findings and the effects of comorbid PTSD and dissociation on HF-HRV are not yet completely understood. This study aim to investigate HF-HRV during resting-state and an ER task in female BPD patients with comorbid PTSD (BPD + PTSD), patients without this comorbidity (BPD), and healthy controls (HC).

METHODS

57 BPD patients (BPD: n = 37, BPD + PTSD: n = 20) and 27 HC performed an ER task with neutral, positive, and negative images. Participants were instructed to either attend these pictures or to down-regulate their upcoming emotions using cognitive reappraisal. Subjective arousal and wellbeing, self-reported dissociation, and electrocardiogram data were assessed.

RESULTS

Independent of ER instruction and picture valence, both patient groups (BPD and BPD + PTSD) reported higher subjective arousal and lower wellbeing; patients with BPD + PTSD further exhibited significantly lower HF-HRV compared with the other groups. Higher self-reported state dissociation predicted higher HF-HRV during down-regulating v. attending negative pictures in BPD + PTSD.

CONCLUSIONS

Findings suggest increased emotional reactivity to negative, positive, and neutral pictures, but do not provide evidence for deficits in instructed ER in BPD. Reduced HF-HRV appears to be particularly linked to comorbid PTSD, while dissociation may underlie attempts to increase ER and HF-HRV in BPD patients with this comorbidity.

One-minute heart rate variability - an adjunct for airway obstruction identification

Heart rate variability (HRV) reflects cardiac and autonomic nervous system activity. It is usually measured over a relatively prolonged period and presented using multiple parameters. Here, we studied rapid HRV changes during airway obstruction using a short (1 min) sampling window. Forty healthy volunteers underwent a trial of obstructed breathing. Heart rate was recorded during three consecutive sets comprised of 1-min control followed by 1 min of obstructed breathing, with 1 min of rest between sets. Time and frequency domain analysis were used to compare HRV during control versus obstructed breathing. Compared with control, HRV intensely increased during obstructed breathing: R-R intervals (time between consecutive R waves) standard deviation increased from 65 to 108 msec (P < 0.0001), root mean square of successive R-R interval from 61 to 82 msec (P = 0.001), number of pairs of successive R-R intervals that differ by more than 50 msec (NN50) from 16.5 to 25.3 events (P < 0.0001), and proportion of NN50 divided by total number of R-R intervals from 26.6 to 35.1% (P = 0.001). Low frequency power increased by more than fourfold (P < 0.0001), allowing 90% sensitivity and 75% specificity for identifying airway obstruction (ROC area 0.88, P < 0.0001). We observed a rapid intense increase in HRV during obstructed breathing, significant enough to detect during a short 1-min sampling window. These findings suggest that HRV may be useful for rapid detection of airway obstruction, especially in situations where end-tidal CO2 monitoring is not optimal, such as during partial airway obstruction.

[Psychosomatic research in 2018: Lost illusions, renewed hopes]

A critical analysis of the basic hypotheses of psychosomatic research and the sometimes hasty assertions drawn from the previous works makes it possible to better discern the data confirmed by the most recent works or the most rigorous meta-analyses and to highlight the emerging tracks. If the hypothesis of behavioral patterns specifically related to the risk of certain pathologies seems abandoned, the predictive value of depression in the cardiovascular field, more than in that of oncology, becomes clearer. Negative affect and impaired emotional awareness emerge as two complementary factors of somatic vulnerability. Several vulnerability factors seem all the more effective as they affect individuals of lower socio-economic status. Social exclusion feeling and its links with the inflammatory response appear to be a possible common denominator, both for depression and for many somatic conditions. A series of studies on the cerebral regulation of emotions and stress, as well as on bidirectional brain-bowel relations and on the mediating role of the gut microbiota, complements the available epidemiological data. The same is true for certain advances in behavioral neuro-economics, which inform the decision-making processes of patients facing preventive health choices. Lastly, it appears that a significant part of the excess mortality associated with the existence of severe mental disorders is not due to factors inherent to the patients themselves, but to disparities in the quality of the care provided to them.

Effects of office workstation type on physical activity and stress

OBJECTIVE

Office environments have been causally linked to workplace-related illnesses and stress, yet little is known about how office workstation type is linked to objective metrics of physical activity and stress. We aimed to explore these associations among office workers in US federal office buildings.

METHODS

We conducted a wearable, sensor-based, observational study of 231 workers in four office buildings. Outcome variables included workers' physiological stress response, physical activity and perceived stress. Relationships between office workstation type and these variables were assessed using structural equation modelling.

RESULTS

Workers in open bench seating were more active at the office than those in private offices and cubicles (open bench seating vs private office=225.52 mG (31.83% higher on average) (95% CI 136.57 to 314.46); open bench seating vs cubicle=185.13 mG (20.16% higher on average) (95% CI 66.53 to 303.72)). Furthermore, workers in open bench seating experienced lower perceived stress at the office than those in cubicles (-0.27 (9.10% lower on average) (95% CI -0.54 to -0.02)). Finally, higher physical activity at the office was related to lower physiological stress (higher heart rate variability in the time domain) outside the office (-26.12 ms/mG (14.18% higher on average) (95% CI -40.48 to -4.16)).

CONCLUSIONS

Office workstation type was related to enhanced physical activity and reduced physiological and perceived stress. This research highlights how office design, driven by office workstation type, could be a health-promoting factor.

Correcting the Activity-Specific Component of Heart Rate Variability Using Dynamic Body Acceleration Under Free-Moving Conditions

Heart rate variability (HRV) analysis is a widely used technique to assess sympatho-vagal regulation in response to various internal or external stressors. However, HRV measurements under free-moving conditions are highly susceptible to subjects’ physical activity levels because physical activity alters energy metabolism, which inevitably modulates the cardiorespiratory system and thereby changes the sympatho-vagal balance, regardless of stressors. Thus, researchers must simultaneously quantify the effect of physical activity on HRV to reliably assess sympatho-vagal balance under free-moving conditions. In the present study, dynamic body acceleration (DBA), which was developed in the field of animal ecology as a quantitative proxy for activity-specific energy expenditure, was used as a factor to correct for physical activity when evaluating HRV in freely moving subjects. Body acceleration and heart inter-beat intervals were simultaneously measured in cattle and sheep, and the vectorial DBA and HRV parameters were evaluated at 5-min intervals. Next, the effects of DBA on the HRV parameters were statistically analyzed. The heart rate (HR) and most of the HRV parameters were affected by DBA in both animal species, and the inclusion of the effect of DBA in the HRV analysis greatly influenced the frequency domain and nonlinear HRV parameters. By removing the effect of physical activity quantified using DBA, we could fairly compare the stress levels of animals with different physical activity levels under different management conditions. Moreover, we analyzed and compared the HRV parameters before and after correcting for the mean HR, with and without inclusion of DBA. The results were somewhat unexpected, as the effect of DBA was a highly significant source of HRV also in parameters corrected for mean HR. In conclusion, the inclusion of DBA as a physical activity index is a simple and useful method for correcting the activity-specific component of HRV under free-moving conditions.

Improving Real-Life Estimates of Emotion Based on Heart Rate: A Perspective on Taking Metabolic Heart Rate Into Account

Extracting information about emotion from heart rate in real life is challenged by the concurrent effect of physical activity on heart rate caused by metabolic need. “Non-metabolic heart rate,” which refers to the heart rate that is caused by factors other than physical activity, may be a more sensitive and more universally applicable correlate of emotion than heart rate itself. The aim of the present article is to explore the evidence that non-metabolic heart rate, as it has been determined up until now, indeed reflects emotion. We focus on methods using accelerometry since these sensors are readily available in devices suitable for daily life usage. The evidence that non-metabolic heart rate as determined by existing methods reflect emotion is limited. Alternative possible routes are explored. We conclude that for real-life cases, estimating the type and intensity of activities based on accelerometry (and other information), and in turn use those to determine the non-metabolic heart rate for emotion is most promising.

Quantitative Analysis of the Effect of an Ectopic Beat on the Heart Rate Variability in the Resting Condition

The purpose of this study is to quantitatively analyze the effect of an ectopic beat on heart rate variability (HRV) in the time domain, frequency domain, and in a non-linear analysis. A quantitative analysis was carried out by generating artificial ectopic beats that probabilistically contained a missed beat or a false-detected beat, and the statistical significance was evaluated though a comparison with an ectopic-free HRV by increasing the ratio of the ectopic beat in 0.1% increments from 0 to 50%. The effect of the interpolation on the ectopic HRV was also investigated by applying nearest-neighbor interpolation, linear interpolation, and cubic spline interpolation. The results confirmed a statistically significant difference (P < 0.05) even in the less-than-1% ectopic HRV in every domain. When interpolation was applied, there were differences according to the interpolation method used, but statistical significance was secured for an ectopic beat ratio from 1 to 2% to several tens of a percent. In the effect, linear interpolation, and spline interpolation were confirmed to have a higher effect on the high-frequency related HRV variables, and nearest-neighbor interpolation had a higher effect on low-frequency related variables.

Stopping the Train of Thought: A Pilot Study Using an Ecological Momentary Intervention with Twice-Daily Exposure to Natural versus Urban Scenes to Lower Stress and Rumination

BACKGROUND

Stress, and specifically perseverative cognition, is considered to have considerable detrimental effects on mental and physical health. Interventions that can offer temporary stress relief could, therefore, bring considerable health benefits. Previous research has pointed to stress-reducing effects of exposure to nature after acute stressors, but has not yet investigated effects in the realm of everyday life. The present pilot study explores whether an ecological momentary intervention using exposure to natural images could be effective in lowering stress and improve mood.

METHODS

Fifteen participants (12 females) scoring above threshold on stress, depression, or anxiety completed two study periods of 6 days. They watched an urban (control) or natural slideshow twice daily. Using Ecological Momentary Assessment, effects on mood, and stress-related complaints were measured in everyday life.

RESULTS

Compliance to the study protocol was high, especially in the first week, with slightly more videos watched in the morning than in the evening. We found indications of improvements in mood, self-reported worrying (but not stress levels), and heart rate.

CONCLUSIONS

The results suggest that twice-daily exposure to restorative visual content could be a viable Ecological Momentary Intervention, with the potential to reduce self-reported worry, lower autonomic activity, and increase positive affect.

Effectiveness of a smartphone-based worry-reduction training for stress reduction: A randomized-controlled trial

OBJECTIVE

Perseverative cognition (e.g. worry) and unconscious stress are suggested to be important mediators in the relation between stressors and physiological health. We examined whether a smartphone-based worry-reduction training improved a physiological marker of stress (i.e. increased heart rate variability [HRV]) and unconscious stress.

DESIGN

Randomised-controlled trial was conducted with individuals reporting work stress (n = 136). Participants were randomised to the experimental, control or waitlist condition (resp. EC, CC, WL). The EC and CC registered emotions five times daily for four weeks. The EC additionally received a worry-reduction training with mindfulness exercises.

MAIN OUTCOME MEASURES

Primary outcome was 24-h assessments of HRV measured at pre-, mid- and post-intervention. Secondary outcomes were implicit affect and stress. Effects on heart rate and other psychological outcomes were explored.

RESULTS

A total of 118 participants completed the study. No change from pre- to post-intervention was observed for the primary or secondary outcomes. The change over time was not different between conditions.

CONCLUSION

Findings suggest that the training was ineffective for improving HRV or psychological stress. Future studies may focus on alternative smartphone-based stress interventions, as stress levels are high in society. There is need for easy interventions and smartphones offer possibilities for this.

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. This novel perspective necessitates a reconstruction of current stress theory, which we address in this paper. We discuss a variety of very common situations without stressors but with prolonged stress responses, that are not, or not likely to be caused by stressors, including loneliness, low social status, adult life after prenatal or early life adversity, lack of a natural environment, and less fit bodily states such as obesity or fatigue. We argue that in these situations the default stress response may be chronically disinhibited due to unconsciously perceived generalized unsafety. Also, in chronic stress situations such as work stress, the prolonged stress response may be mainly caused by perceived unsafety in stressor-free contexts. Thus, GUTS identifies and explains far more stress-related physiological activity that is responsible for disease and mortality than current stress theories.

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. Recently, Verkuil et al. (2016) introduced a laboratory-based method to measure additional HRV reduction in everyday life, and reductions in HRV related to psychological stress. In the current paper, we discuss alternative methods to detect additional HRV reductions, in real life data sets without the necessity of laboratory-based calibration, and even in existing data sets. All of these methods use a subset of 24h' worth of HRV and movement data to do so: either the first 10min of every hour, the full 24h, a combination of 10min from three consecutive hours, or a classification of level of movement. We also present a method to visualize HRV and movement data to be able to detect episodes of reduced additional HRV optically. The method that used the full 24h' worth of data detected the largest percentage of episodes of reduced additional HRV that actually match with self-reported stress levels, making this method the most promising.

Heart Rate Variability and Cardiac Vagal Tone in Psychophysiological Research - Recommendations for Experiment Planning, Data Analysis, and Data Reporting

Psychophysiological research integrating heart rate variability (HRV) has increased during the last two decades, particularly given the fact that HRV is able to index cardiac vagal tone. Cardiac vagal tone, which represents the contribution of the parasympathetic nervous system to cardiac regulation, is acknowledged to be linked with many phenomena relevant for psychophysiological research, including self-regulation at the cognitive, emotional, social, and health levels. The ease of HRV collection and measurement coupled with the fact it is relatively affordable, non-invasive and pain free makes it widely accessible to many researchers. This ease of access should not obscure the difficulty of interpretation of HRV findings that can be easily misconstrued, however, this can be controlled to some extent through correct methodological processes. Standards of measurement were developed two decades ago by a Task Force within HRV research, and recent reviews updated several aspects of the Task Force paper. However, many methodological aspects related to HRV in psychophysiological research have to be considered if one aims to be able to draw sound conclusions, which makes it difficult to interpret findings and to compare results across laboratories. Those methodological issues have mainly been discussed in separate outlets, making difficult to get a grasp on them, and thus this paper aims to address this issue. It will help to provide psychophysiological researchers with recommendations and practical advice concerning experimental designs, data analysis, and data reporting. This will ensure that researchers starting a project with HRV and cardiac vagal tone are well informed regarding methodological considerations in order for their findings to contribute to knowledge advancement in their field.