scholarly journals An effect size distribution analysis of heart rate variability studies: Recommendations for reporting the magnitude of group differences

2016 ◽  
Author(s):  
Daniel S. Quintana
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Size Distribution ◽  
Effect Size ◽  
Case Control ◽  
The Body ◽  
Effect Sizes ◽  
Group Differences ◽  
Distribution Analysis ◽  
Effect Size Distribution

AbstractThe calculation of heart rate variability (HRV) is a popular tool used to investigate differences in cardiac autonomic control between population samples. When interpreting effect sizes to quantify the magnitude of group differences, researchers typically use Cohen's guidelines of small (0.2), medium (0.5), and large (0.8) effects. However, these guidelines were only proposed for use when the effect size distribution (ESD) was unknown. Despite the availability of effect sizes from hundreds of HRV studies, researchers still largely rely on Cohen's guidelines to interpret effect sizes. This article describes an ESD analysis of 297 HRV effect sizes from case-control studies, revealing that the 25th, 50th, and 75th effect size percentiles correspond with effect sizes of 0.25, 0.5, and 0.84, respectively. The ESD for separate clinical groups are also presented. The data suggests that Cohen's guidelines underestimate the magnitude of small and large effect sizes for the body of HRV case-control research. Therefore, to better reflect observed HRV effect sizes, the data suggest that effect sizes of 0.25, 0.5, and 0.85 should be interpreted as small, medium, and large effects. Researchers are encouraged to use the ESD dataset or their own collected datasets in tandem with the provided analysis script to perform bespoke ESD analyses relevant to their specific research area.

scholarly journals The distribution of common-variant effect sizes

2020 ◽  
Author(s):  
Luke Jen O’Connor
Keyword(s):  
Sample Size ◽  
Size Distribution ◽  
Effect Size ◽  
Genetic Architecture ◽  
Common Variant ◽  
Effect Sizes ◽  
Summary Statistics ◽  
Genome Wide ◽  
Variant Effect ◽  
Effect Size Distribution

AbstractThe genetic effect-size distribution describes the number of variants that affect disease risk and the range of their effect sizes. Accurate estimates of this distribution would provide insights into genetic architecture and set sample-size targets for future genome-wide association studies. We developed Fourier Mixture Regression (FMR) to estimate common-variant effect-size distributions from GWAS summary statistics. We validated FMR in simulations and in analyses of UK Biobank data, using interim-release summary statistics (max N=145k) to predict the results of the full release (N=460k). Analyzing summary statistics for 10 diseases (avg Neff=169k) and 22 other traits, we estimated the sample size required for genome-wide significant SNPs to explain 50% of SNP-heritability. For most diseases the requisite number of cases is 100k-1M, an attainable number; ten times more would be required to explain 90% of heritability. In well-powered GWAS, genome-wide significance is a conservative threshold, and loci at less stringent thresholds have true positive rates that remain close to 1 if confounding is controlled. Analyzing the shape of the effect-size distribution, we estimate that heritability accumulates across many thousands of SNPs with a wide range of effect sizes: the largest effects (at the 90th percentile of heritability) are 100 times larger than the smallest (10th percentile), and while the midpoint of this range varies across traits, its size is similar. These results suggest attainable sample size targets for future GWAS, and they underscore the complexity of genetic architecture.

scholarly journals Factors influencing the effect size distribution of adaptive substitutions

2016 ◽  
Vol 283 (1828) ◽  
pp. 20153065 ◽  
Author(s):  
Emily L. Dittmar ◽  
Christopher G. Oakley ◽  
Jeffrey K. Conner ◽  
Billie A. Gould ◽  
Douglas W. Schemske
Keyword(s):  
Size Distribution ◽  
Effect Size ◽  
Evolutionary Biology ◽  
Empirical Work ◽  
Effect Sizes ◽  
Recent Theory ◽  
Early Theory ◽  
Evolutionary Forces ◽  
New Research ◽  
Effect Size Distribution

The distribution of effect sizes of adaptive substitutions has been central to evolutionary biology since the modern synthesis. Early theory proposed that because large-effect mutations have negative pleiotropic consequences, only small-effect mutations contribute to adaptation. More recent theory suggested instead that large-effect mutations could be favoured when populations are far from their adaptive peak. Here we suggest that the distributions of effect sizes are expected to differ among study systems, reflecting the wide variation in evolutionary forces and ecological conditions experienced in nature. These include selection, mutation, genetic drift, gene flow, and other factors such as the degree of pleiotropy, the distance to the phenotypic optimum, whether the optimum is stable or moving, and whether new mutation or standing genetic variation provides the source of adaptive alleles. Our goal is to review how these factors might affect the distribution of effect sizes and to identify new research directions. Until more theory and empirical work is available, we feel that it is premature to make broad generalizations about the effect size distribution of adaptive substitutions important in nature.

scholarly journals Direct measurement of vagal tone in rats does not show correlation to HRV

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joseph T. Marmerstein ◽  
Grant A. McCallum ◽  
Dominique M. Durand
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Neural Activity ◽  
Vagal Tone ◽  
Neural Recording ◽  
The Body ◽  
Autonomic Nerve ◽  
Vagal Activity ◽  
Recording Technology

AbstractThe vagus nerve is the largest autonomic nerve, innervating nearly every organ in the body. “Vagal tone” is a clinical measure believed to indicate overall levels of vagal activity, but is measured indirectly through the heart rate variability (HRV). Abnormal HRV has been associated with many severe conditions such as diabetes, heart failure, and hypertension. However, vagal tone has never been directly measured, leading to disagreements in its interpretation and influencing the effectiveness of vagal therapies. Using custom carbon nanotube yarn electrodes, we were able to chronically record neural activity from the left cervical vagus in both anesthetized and non-anesthetized rats. Here we show that tonic vagal activity does not correlate with common HRV metrics with or without anesthesia. Although we found that average vagal activity is increased during inspiration compared to expiration, this respiratory-linked signal was not correlated with HRV either. These results represent a clear advance in neural recording technology but also point to the need for a re-interpretation of the link between HRV and “vagal tone”.

HRV Biofeedback and Addiction: Rehabbing Body, Mind and Spirit

Biofeedback ◽  
2021 ◽  
Vol 49 (1) ◽  
pp. 10-17
Author(s):  
Amy Hudson
Keyword(s):  
Heart Rate ◽  
Chronic Pain ◽  
Heart Rate Variability ◽  
The Body ◽  
Heart Rate Variability Biofeedback ◽  
The Mind

Addiction is a devastating disease of the body, the mind, and even the personality. Recent research shows that heart rate variability biofeedback can help the alcoholic/addict recover in three crucial ways, namely (1) treating the associated comorbidities (depression, anxiety, chronic pain), (2) treating the physiology around craving, and (3) returning to a loving and nurturing relationship with one's own body instead of an abusive and exploitive one.

scholarly journals Linear and Complex Measures of Heart Rate Variability during Exposure to Traffic Noise in Healthy Women

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Myrela Alves ◽  
David M. Garner ◽  
Anne M. G. G. Fontes ◽  
Luiz Vinicius de Alcantara Sousa ◽  
Vitor E. Valenti
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Effect Size ◽  
Noise Exposure ◽  
Global Analysis ◽  
Traffic Noise ◽  
Large Effect Size ◽  
City Street ◽  
Linear Behavior ◽  
Healthy Female

Previous studies have described significant impact of different types of noise on the linear behavior of heart rate variability (HRV). However, there are few studies regarding the complexity of HRV during exposure to traffic noise. In this study, we evaluated the complexity of HRV during traffic noise exposure. We analyzed 31 healthy female students aged between 18 and 30 years. Volunteers remained at rest seated under spontaneous breathing during 10 minutes with an earphone turned off, and then they were exposed to traffic noise through an earphone for a period of 10 minutes. The traffic noise was recorded from a very busy city street and the sound was comprised of car, bus, and trucks engines and horn (71–104 dB). We observed no significant changes in the linear analysis of HRV. CFP3 (Cohen’s d=1.28, large effect size) and CFP6 (Cohen’s d=1.11, large effect size) parameters of chaotic global analysis and Shannon (Cohen’s d=1.13, large effect size), Renyi (Cohen’s d=1.06, large effect size), and Tsallis (Cohen’s d=1.14, large effect size) entropies significantly increased p<0.005 during traffic noise exposure. In conclusion, traffic noise under laboratory conditions increased the complexity of HRV through chaotic global analysis and some measures of entropy in healthy females.

scholarly journals Psychological and physiological effects of emotion focused training for self-compassion and self-protection

2019 ◽  
Vol 22 (2) ◽  
Author(s):  
Júlia Halamová ◽  
Jana Koróniová ◽  
Martin Kanovský ◽  
Mária Kénesy Túniyová ◽  
Nuriye Kupeli
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Active Control ◽  
Expressive Writing ◽  
Intervention Group ◽  
Effect Sizes ◽  
Control Group ◽  
Active Control Group ◽  
Self Compassion ◽  
Self Protection

Emotion Focused Training for Self-Compassion and Self-Protection (EFT-SCP) is a novel intervention developed on the basis of the latest findings on self-criticism from Emotion-focused therapy and existing programs designed to cultivate compassion. EFT-SCP is designed to encourage participants to cultivate self-compassion and protective anger as a way of reducing selfcriticism. Our goal was to investigate the effect of this group-based intervention on self-criticism, self-protection, and self-compassion. A total of 73 students were assigned to the EFT-SCP intervention (n=19), no-treatment control (n=34) or to an active control group (n=20). The intervention group met weekly for 1.5 hours and were instructed to incorporate EFT-SCP tasks into their daily life for 12 weeks. Whilst the no-treatment group did not undergo an intervention, the active control group completed an adapted expressive writing task once a week. In addition to the assessment of heart rate variability during imagery tasks, participants also completed self-reported measures of self-compassion and self-criticism before and after the intervention. Compared with both control groups, the intervention group showed a significant increase in heart rate variability following EFT-SCP (during self-critical imagery, P=.049; probability of superiority was .63, and during self-compassionate imagery P=.007; probability of superiority was .62, both effect sizes were medium) and significant decreases in self-criticism (Hated Self P=.017; .34 and Inadequate Self P<.001; .33) and selfuncompassionate responding (P<.001; .39). All three effect sizes were small. Participating in EFT-SCP had a positive effect on psychological and physiological outcomes.

scholarly journals Applicability of Dmax Method on Heart Rate Variability to Estimate the Lactate Thresholds in Male Runners

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Eduardo Marcel Fernandes Nascimento ◽  
Diego Antunes ◽  
Paulo Cesar do Nascimento Salvador ◽  
Fernando Klitzke Borszcz ◽  
Ricardo Dantas de Lucas
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Blood Lactate ◽  
Standard Error ◽  
Intraclass Correlation ◽  
Effect Sizes ◽  
Initial Speed ◽  
Limits Of Agreement ◽  
Aerobic Threshold ◽  
Post Hoc

Introduction. The purpose of this study was to evaluate the application of the Dmax method on heart rate variability (HRV) to estimate the lactate thresholds (LT), during a maximal incremental running test (MIRT). Methods. Nineteen male runners performed two MIRTs, with the initial speed at 8 km·h−1 and increments of 1 km·h−1 every 3 minutes, until exhaustion. Measures of HRV and blood lactate concentrations were obtained, and lactate (LT1 and LT2) and HRV (HRVTDMAX1 and HRVTDMAX2) thresholds were identified. ANOVA with Scheffe’s post hoc test, effect sizes (d), the bias ± 95% limits of agreement (LoA), standard error of the estimate (SEE), Pearson’s (r), and intraclass correlation coefficient (ICC) were calculated to assess validity. Results. No significant differences were observed between HRVTDMAX1 and LT1 when expressed for speed (12.1 ± 1.4 km·h−1 and 11.2 ± 2.1 km·h−1; p=0.55; d = 0.45; r = 0.46; bias ± LoA = 0.8 ± 3.7 km·h−1; SEE = 1.2 km·h−1 (95% CI, 0.9–1.9)). Significant differences were observed between HRVTDMAX2 and LT2 when expressed for speed (12.0 ± 1.2 km·h−1 and 14.1 ± 2.5 km·h−1; p=0.00; d = 1.21; r = 0.48; bias ± LoA = −1.0 ± 1.8 km·h−1; SEE = 1.1 km·h−1 (95% CI, 0.8–1.6)), respectively. Reproducibility values were found for the LT1 (ICC = 0.90; bias ± LoA = −0.7 ± 2.0 km·h−1), LT2 (ICC = 0.97; bias ± LoA = −0.1 ± 1.1 km·h−1), HRVTDMAX1 (ICC = 0.48; bias ± LoA = −0.2 ± 3.4 km·h−1), and HRVTDMAX2 (ICC = 0.30; bias ± LoA = 0.3 ± 3.5 km·h−1). Conclusions. The Dmax method applied over a HRV dataset allowed the identification of LT1 that is close to aerobic threshold, during a MIRT.

scholarly journals Role of physiological monitoring in educational organizations

2019 ◽  
Vol 72 ◽  
pp. 03005
Author(s):  
Olga Shchkvirina ◽  
Dinamutdin Misirov ◽  
Marina Akopyan ◽  
Irina Loseva
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Functional State ◽  
Initial Period ◽  
Educational Environment ◽  
Convincing Evidence ◽  
Educational Process ◽  
The Body ◽  
Objective Criterion ◽  
Functional Capabilities

An indicators analysis of the first-graders functional state and vegetative homeostasis obtained in the initial period of adaptation to the educational environment revealed gender differences in the rates of the adaptation process to new learning conditions. It has been established that girls’ adaptation mechanisms turn on earlier than boys’, with their similar orientation. The article provides an experimental justification of the indicators use legitimacy for heart rate variability to assess the functional state of the body in the acute period of adaptation to the educational environment. The importance of teacher physiological literacy for the optimization of the educational process is substantiated. The results of the study are convincing evidence of the knowledge importance for the physiological foundations of the occurrence and course of physiological and mental processes, stable individual psycho-physiological characteristics for the organization of the learning environment, corresponding to the functional capabilities of the body. This argument is also confirmed by many years of experience among master students key competencies development, which allow using such an objective criterion as the current functional state of the body to ensure, through the joint efforts of parents, teachers, psychologists, and doctors, the correction of the educational environment and psycho-physiological resistance of individual to it. The established differences in the dynamics of heart rate variability indicators for girls and boys can be used to form a health-saving program in school settings.

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