Anxiety and heart rate variability before sleep indicate chronic stress in students

The purpose of the present study was to investigate the effect of chronic stress on the first-night effect in terms of autonomic nervous system activity and anxiety. Participants (N = 11; M age = 20.3 yr., SD = 0.47) included six with high stress (High stress group) and five with low stress (Low stress group), for whom all EEG data were available from three consecutive nights. Heart rate variability was calculated using the MemCalc method. The ratio of low to high frequency of heart rate variability before sleep onset in the High stress group on the first night indicated significantly higher activities than the ratio before sleep onset in the Low stress group. No significant difference in sleep latency was found between the two groups. However, the High stress group was more aware of anxiety than was the Low stress group, and the former estimated more subjective difficulty in falling asleep. These results suggest that measuring LF/HF before sleep may constitute a new way to assess chronic stress.     

Mental load,heart rate and heart rate variability

Summary Several investigators have shown that diminished sinus arrhythmia can be seen as an indication of increased mental load. The present experiment deals with the influence of different levels of mental load, operationalized as the number of binary choices per minute, on the regularity of the heart rate. Also we investigated the influence of four different rest conditions on the regularity of the heart rate.The results show that sinus arrhythmia scores differentiate significantly between several levels of mental load, but heart frequency appeared to be an even better indicator.No significant differences were found between the four rest conditions. Stability over three subsequent measurement sessions was satisfactory, and reliability within the measurement periods was very high.

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Zusammenfassung Mehrere Forscher haben gezeigt, daß abnehmende Sinusarrhythmie betrachtet werden kann als ein Indikator zunehmender mentaler Belastung.In der vorliegenden Untersuchung handelt es sich um den Einfluß verschiedener Niveaus der mentalen Belastung, operationalisiert als die Zahl der binären Wahlen pro Minute, auf die Regelmäßigkeit der Herzfrequenz.Außerdem untersuchten wir den Einfluß vier verschiedener Ruhezustände auf die Regelmäßigkeit der Herzfrequenz.Die Ergebnisse zeigen, daß auf Grund Sinusarrhythmiedaten differenziert werden kann zwischen verschiedenen Niveaus mentaler Belastung, aber die Herzfrequenz erweist sich sogar als ein besserer Indikator.Man stellte keine signifikanten Unterschiede zwischen den vier verschiedenen Ruhezuständen fest.Die Stabilität während drei verschiedener Meßperioden war befriedigend, und die Zuverlässigkeit der Messungen (reliability) innerhalb der Meßperioden war sehr groß.

     

Rhythmic organization of heart rate in breast-fed and bottle-fed newborn infants

Heart rates and behavioural states of 14 breast-fed and 14 bottlefed newborn infants were assessed every 30 seconds for 2 continuous hours. The 240 observations of heart rate were treated as time-series data and spectrum-analysed for behavioural rhythmicities. Of the 28 infants, 25 showed reliable cycles in heart rate; 22 of the 25 infants showed a dominant frequency with a 30–60 min periodicity, one that approximates the basic-rest activity cycle (BRAC). In addition to this basic cycle, additional higher frequency cycles in long-term heart rate variability were evident in the spectra of many infants. Breast-fed newborns had greater numbers of reliable cycles in heart rate than bottle-fed newborns. Further, breast-fed newborns had lower overall mean heart rates and lower mean heart rates in Quiet and Active Sleep states than bottle-fed newborns. Bottle-fed newborns were observed more often in Quiet Sleep than breast-fed newborns. Without knowledge of the specific mechanisms causing these behavioural differences, the results of this study suggest that the context in which breast-feeding occurs results in a more complex and energy-efficient pattern of behavioural organization than the context of bottle-feeding.     

Self-implication and heart rate variability during simulated exposure to flight-related stimuli

In the present study, the relationship between self-implication during simulated exposure to feared stimuli and Heart Rate Variability (HRV) was explored within the framework of the dynamical systems model of emotion regulation proposed by Thayer and Lane (Thayer, J.F., and Lane, R.D. (2000). A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61, 201–216.). An analogue sample of flight phobics (n=15) and a matched non-phobic control group (n=15) were presented with flight-related pictures, flight-related sounds or flight-related pictures and sounds. Significant differences on self-implication during exposure to flight-related sounds were found between low and high HRV fearful flyers, the former being more self-implied. However, the expected HRV decreases in the phobic participants exposed to feared stimuli were not found. These results emphasize the need to distinguish between high and low HRV fearful flyers in order to make a better use of the simulated exposure treatments.     

Human visual evoked responses are related to heart rate.

The purpose of the present experiment was to determine the relation between changes in heart rate and averaged evoked potentials. Sixteen male subjects with variable heart rates received 50 flashes of light during fast heart beats, 50 during slow heart beats, and 50 during midrange heart rate level. Evoked responses were recorded from the scalp overlying the right and left occipital lobes. Heart rate, respiration, eye movements, and cephalic blood flow were also recorded. The results indicated that spontaneous changes in heart rate are related to changes in visual evoked responses and that this relation differs for the two cerebral hemispheres. Furthermore, cephalic pulse amplitude was largest following slow heart beats and smallest following fast heart beats, which suggests that changes in heart rate are related to changes in cerebrovascular as well as electrocortical activity. The results are discussed in terms of formulations derived from behavioral studies regarding the relation between cardiovascular activity and attentional processes.     

An on-line program to calculate respiratory sinus arrhythmia amplitude

A variety of evidence shows that the amplitude of respiratory sinus arrhythmia (RSA)—the peak-to-peak variations in heart rate caused by respiration—is a valid and reliable index of para-sympathetic cardiac control. An on-line program to calculate RSA amplitude on a breath-by-breath basis is described. The validity of the RSA amplitude values obtained through the computer pro-gram were tested in two studies. From the first one, the correlations between RSA amplitude and a set of cardiorespiratory variables, under both rest and auditory stimulation conditions, are reported. In the second study, the effect of atropine administration on the RSA amplitude, under both rest and mental load conditions, was examined. The results of both studies are con-gruent with predictions and suggest the usefulness of the software.     

Cognitive reappraisal increases heart rate variability in response to an anger provocation

Adaptive self-regulatory responses to negative events are associated with good mental health, social functioning, and physical health. Two forms of emotion regulation that have received attention within the context of anger are cognitive reappraisal and expressive suppression. Research suggests that greater heart rate variability (HRV) is a physiological indicator of adaptive emotion regulation and decreased mental load. In the present experiment, we recorded HRV while 131 undergraduate women viewed an anger-inducing video of a fellow student arguing for a position counter to that of the participant on an important political issue. Immediately prior to viewing, participants were instructed to reappraise, suppress their emotions, or simply watch the video as normal. Participants in the reappraisal condition showed increased HRV whereas those in the suppression and control condition showed no such increase. These results provide support for increased HRV as a biological correlate of adaptive emotion regulation. One implication is that cognitive reappraisal might afford greater autonomic flexibility when an individual is confronted with anger-inducing events.     

Matters of the variable heart: respiratory sinus arrhythmia response to marital interaction and associations with marital quality

Maintenance of relationship quality requires self-regulation of emotion and social behavior, and women often display greater effort in this regard than do men. Furthermore, such efforts can deplete the limited capacity for self-regulation. In recent models of self-regulation, resting level of respiratory sinus arrhythmia, quantified as high-frequency heart rate variability (HF-HRV), is an indicator of self-regulatory capacity, whereas transient increases in HF-HRV reflect self-regulatory effort. To test these hypotheses in marriage, 114 young couples completed measures of marital quality and a positive, neutral, or negative initial marital task, preceded and followed by resting baseline assessments of HF-HRV. Couples then discussed a current marital disagreement. Resting HF-HRV was correlated with marital quality, suggesting that capacity for self-regulation is associated with adaptive functioning in close relationships. For women but not men, the negative initial task produced a decrease in resting HF-HRV. This effect was mediated by the husbands' negative affect response to the task and their ratings of wives as controlling and directive. When the subsequent disagreement discussion followed the negative initial task, women displayed increased HF-HRV during the discussion but a decrease when it followed the neutral or positive task. The valence of the initial task had no effect on men's HF-HRV during disagreement. Negative marital interactions can reduce women's resting HF-HRV, with potentially adverse health consequences. Women's reduced health benefit from marriage might reflect the depleting effects on self-regulatory capacity of their greater efforts to manage relationship quality.     

Variable heart rate and a flexible mind: Higher resting-state heart rate variability predicts better task-switching

The neurovisceral integration model proposes that heart rate variability (HRV) is linked to prefrontal cortex activity via the vagus nerve, which connects the heart and the brain. HRV, an index of cardiac vagal tone, has been found to predict performance on several cognitive control tasks that rely on the prefrontal cortex. However, the link between HRV and the core cognitive control function “shifting” between tasks and mental sets is under-investigated. Therefore, the present study tested the neurovisceral integration model by examining, in 90 participants, the relationship between vagally mediated resting-state HRV and performance in a task-switching paradigm that provides a relatively process-pure measure of cognitive flexibility. As predicted, participants with higher resting-state HRV (indexed both by time domain and frequency domain measures) showed smaller switch costs (i.e., greater flexibility) than individuals with lower resting-state HRV. Our findings support the neurovisceral integration model and indicate that higher levels of vagally mediated resting-state HRV promote cognitive flexibility.     

Respiratory sinus arrhythmia in response to fear-relevant and fear-irrelevant stimuli

Heart period variability and heart rate were studied in 15 women and 15 men while they were viewing negatively (snakes/spiders), neutrally (scenic views), and positively (cats and kittens/puppies and dogs) valenced films. Time-frequency analyses of the heart period variability power spectrum in the high frequency region (0.12-0.4 Hz), reflecting respiratory sinus arrhythmia (RSA), were carried out during 5 minutes in each condition. The main finding showed that RSA-magnitude (high frequency power) was inversely related to emotional valence: lowest magnitudes were found in response to positive films, and highest magnitude to negative films. The findings were interpreted as reflecting motor or behavioral inhibition, and increased attention to negatively valenced, stimuli.     

A method for measuring dynamic respiratory sinus arrhythmia (RSA) in infants and mothers

The measurement of respiratory sinus arrythmia (RSA) in infants, children and adults is critical to the study of physiological regulation, and more recently, interpersonal physiological covariation, but it has been impeded by methods that limit its resolution to 30 s or longer. Recent analytical developments have suggested methods for studying dynamic RSA in adults, and we have extended this work to the study of infants and mothers. In the current paper, we describe a new analytical strategy for estimating RSA time series for infants and adults. Our new method provides a means for studying physiological synchrony in infant-mother dyads that offers some important advantages relative to existing methods that use inter-beat-intervals (e.g. Feldman, Magori-Cohen, Galili, Singer, & Louzoun, 2011). In the middle sections of this paper, we offer a brief tutorial on calculating RSA continuously with a sliding window and review the empirical evidence for determining the optimal window size. In order to confirm the reliability of our results, we briefly discuss testing synchrony by randomly shuffling the dyads to control for spurious correlations, and also by using a bootstrapping technique for calculating confidence intervals in the cross-correlation function. One important implication that emerges from applying this method is that it is possible to measure both positive and negative physiological synchrony and that these categorical measures are differentially predictive of future outcomes.     

Facets of psychopathy, heart rate variability and cognitive function

The aim of the present study was to investigate whether the four facets of Hare's Psychopathy Checklist-Revised (PCL-R; Hare, 1991; Bolt, Hare, Vitale, & Newman, 2004) were related to physiological and cognitive mechanisms. Fifty-three male prisoners participated in this study. Physiological responses were measured as heart rate variability (HRV) and heart rate (HR). Cognitive functions were measured using a continuous performance test (CPT; California Computerized Assessment Package, Abbreviated version) and a working memory test (WMT); based on Baddeley & Hitch (1974). The regression analysis of the HRV revealed that the interpersonal facet explained most of the variance during baseline (28%), CPT (16%), and WMT (12%). This was also true for the HR data during baseline (28%), CPT (20%), WMT (10%), and recovery (13%). The antisocial facet explained 10% of the variance only during baseline. Subjects scoring high compared to low on the interpersonal facet also showed better cognitive functioning. The study suggests that the different facets were differently associated with both physiological and cognitive functions.     

Contact-free measurement of heart rate, respiration rate, and body movements during sleep

We describe a noncontact method for the ambulant measurement of basic sleep physiology parameters in humans, particularly for field studies involving sleep research and sleep disturbances. This method traces the body movements, respiration, and heart action of a person at rest or asleep on a bed, using four high-resolution force sensors installed under the bedposts. The recoil movement of the body at each heartbeat, known as the cardioballistic effect, as well as the lifting and lowering of the thorax, while breathing, causes very small shifts of the center of gravity of the bed and the subject. These shifts are reflected in the altering force distributions across the four sensors. Cardiac and respiratory parameters and the subject’s movement activity can be calculated from the sensor signals. Neither electrodes nor other kinds of transducers are in direct contact with the subject, which is the main advantage of this technique over conventional methods. Laboratory experiments were carried out to estimate validity and practicability. The method has been found to be adequate, especially for automated and unattended sleep-data collection over long periods of time.     

The effect of short duration heart rate variability (HRV) biofeedback on cognitive performance during laboratory induced cognitive stress

The aim of this study was to examine the effect of 10 minutes of heart rate variability (HRV) biofeedback on cognitive performance and affect scores during induced stress. Eighteen healthy male volunteers (aged 23–41 years) exposed to work‐related stress, were randomised into an HRV biofeedback intervention (BIO) and a comparative intervention group (COM). Subjects completed a modified Stroop task, which included having to mentally count 18 white squares randomly presented between colour words, before and after a 10‐minute intervention. Subjects also completed questionnaires to rate their anxiety. BIO subjects improved their reaction times and consistency of responses, and made fewer mistakes in counting squares during the modified Stroop task. They also felt more relaxed, less anxious and less sleepy than the COM subjects. In conclusion our results suggest that short duration HRV biofeedback is associated with improved cognitive performance while concurrently aiding relaxation. Copyright © 2010 John Wiley & Sons, Ltd.     

The effects of massage velocity on heart rate and heart rate variability in healthy infants: A randomized crossover study

BackgroundInfant massage, in which mothers stroke their infant’s skin slowly and gently, can cause pleasant sensations in the infant that can be affected by the velocity of massage. However, the massage velocity at which infants feel the most pleasant sensations remains unclear.ObjectiveTo investigate the effects of massage velocity on heart rate (HR) and HR variability (HRV) in healthy infants.MethodTwenty-two infant-mother dyads two to seven months of age were recruited. Mothers stroked their infant’s skin at three massage velocities (5.0, 7.5, and 10.0 cm/s) in a randomized order for 15 min. The rhythm of massage velocity was calculated according to the length of three body areas. The massage velocity of the mothers was regulated using a metronome. HR and HRV (high frequency [HF] and low frequency [LF]) were measured at rest and during massage for each velocity. The effects on pleasantness were evaluated using percent change in median baseline value compared with median values for the three massage velocities. Statistical analysis was performed using analysis of variance mixed effect models to exclude “period” and “carryover” effects during massage.ResultsWhen measuring HF, massage (7.5 cm/s) caused a significant increase in pleasantness compared with 10.0 cm/s (p = 0.04). The HR and LF/HF ratio were not significantly changed between velocities.ConclusionResults of this study suggested that a massage velocity of 7.5 cm/s was the most pleasant for infants. Future research should investigate the relationship between an infant massage by optimal velocity and infant development in longitudinal studies.     

Field validity of heart rate variability metrics produced by QRSTool and CMetX

Interest in heart rate variability (HRV) metrics as markers of physiological and psychological health continues to grow beyond those with psychophysiological expertise, increasing the importance of developing suitable tools for researchers new to the field. Allen, Chambers, and Towers (2007) developed QRSTool and CMetX software as simple, user-friendly tools that can be used to compute metrics of HRV. In the present study, the authors examined the field validity of these software tools-that is, their validity when used by nonexperts. In a lab with extensive expertise in psychopathology but not psychophysiology, ECG data were obtained from 63 undergraduates at baseline and during a stressor and then processed using QRSTool and CMetX to produce the 10 HRV indices described in Allen et al. (2007). The indices displayed factor structures and patterns of changes from baseline to stressor that were similar to findings from Allen et al. and consistent with how indices of parasympathetic and sympathetic activity should behave. Results support the field validity of QRSTool and CMetX, suggesting that they are useful for nonexperts in psychophysiology interested in measuring HRV. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

The use of heart rate variability in esports: A systematic review

Heart rate variability (HRV) is a psychophysiological measure of particular interest in esports due to its potential to monitor player self-regulation. This study aimed to systematically review the utilisation of HRV in esports. Consideration was given to the methodological and theoretical underpinnings of previous works to provide recommendations for future research. The protocol was made available on the Open Science Framework. Inclusion criteria were empirical studies, examining HRV in esports, using esports players, published in English. Exclusion criteria were non-peer-reviewed studies, populations with pre-existing clinical illness other than Internet Gaming Disorder (IGD), opinion pieces or review papers. In November 2022 a search of Web of Science, PubMed, and EBSCOHost identified seven studies using HRV in esports. Risk of bias was assessed using the Mixed Methods Appraisal Tool. Narrative review identified two primary uses of HRV in esports; stress response and IGD. A lack of theoretical and methodological underpinning was identified as a major limitation of current literature. Further investigation is necessary before making recommendations regarding the use of HRV in esports. Future research should employ sound theoretical underpinning such as the use of vagally mediated HRV and the robust application of supporting methodological guidelines when investigating HRV in esports.