Laborde et al. (2017) — HRV and Cardiac Vagal Tone in Psychophysiological Research

sourceUpdated 2026-06-15
HRVvagal-toneRMSSDcardiac-vagal-toneresonance-frequencytonic-HRVphasic-HRVneurovisceral-integrationmethodology
Related: Heart Rate Variability (HRV), The Vagal Brake, Respiratory Sinus Arrhythmia (RSA), Resonance Frequency Breathing (0.1 Hz), Nucleus Ambiguus, Meditation as Vagal Brake Training

Laborde et al. (2017) — HRV and Cardiac Vagal Tone in Psychophysiological Research

Full title: Heart Rate Variability and Cardiac Vagal Tone in Psychophysiological Research — Recommendations for Experiment Planning, Data Analysis, and Data Reporting
Authors: Sylvain Laborde, Emma Mosley, Julian F. Thayer
Journal: Frontiers in Psychology 8:213
Year: 2017
DOI: 10.3389/fpsyg.2017.00213
Type: Methodological review
Ingested: 2026-06-15

Summary

Comprehensive methodological guidance for psychophysiological researchers using HRV to index cardiac vagal tone. Covers experimental design, confound control, data analysis, and reporting standards.

Five Theoretical Frameworks for HRV

The paper reviews five models linking HRV to broader constructs — each appears in this knowledge base:

Model Key Author Core Claim
Neurovisceral Integration Thayer et al. PFC → heart via central autonomic network; higher vagal tone = better cognitive + emotional regulation
Polyvagal Theory Porges Higher vagal tone = better social functioning; Ventral/Sympathetic/Dorsal hierarchy
Biological Behavioral Model Grossman & Taylor Vagal tone regulates energy exchange by synchronizing respiratory + cardiovascular processes; higher resting tone = adaptive "energy reserve"
Resonance Frequency Model Lehrer Slow paced breathing at ~0.1 Hz efficiently increases vagal tone via baroreflex synchronization
Psychophysiological Coherence McCraty & Childre Slow paced breathing + positive emotions → "coherence" → broad health benefits

The Three Rs Framework

Laborde et al. recommend structuring every HRV experiment around three measurement points:

  1. Resting (Tonic HRV): baseline HRV at rest — reflects the structural reserve of the vagal brake; higher = more adaptive in most contexts
  2. Reactivity (Phasic HRV): change from baseline to the stressor/task — vagal withdrawal can be adaptive (providing energy for a physical challenge) or maladaptive (reducing executive capacity when PFC engagement is needed)
  3. Recovery: change from task back toward baseline — speed of HRV recovery reflects regulatory flexibility

Key nuance: High tonic HRV enables adaptive phasic responses. In a selective attention task with fearful distractors, high tonic HRV was associated with enhancement of vagal tone under low perceptual load, while low tonic HRV was associated with withdrawal regardless of load.

Tonic vs. Phasic HRV

  • Tonic: measured at one time point (resting baseline); higher is almost universally adaptive. The "structural reserve" this wiki discusses.
  • Phasic: the change from one time point to another. Vagal withdrawal during a stressor is not pathological per se — it's the appropriate "releasing the brake" to mobilize energy. What's maladaptive is failure to recover (slow recovery HRV) or excessive withdrawal during cognitive tasks.

Key Confounds to Control

Stable participant variables:

  • Age, sex (HRV declines with age; sex differences in vagal tone)
  • Smoking, habitual alcohol consumption
  • Weight/BMI (obesity suppresses HRV)
  • Cardioactive medication (antidepressants, antipsychotics, antihypertensives)
  • Oral contraceptives (affect stress reactivity HRV, less so resting HRV)

Transient variables (session-specific):

  • Sleep on the night before
  • Food, caffeine (restrict caffeine before measurement)
  • Physical activity in previous hours
  • Ambient temperature and body position (supine vs. seated changes absolute values significantly)
  • Respiration rate (must control or co-measure; slow breathing inflates HRV independent of vagal tone)

Practical Implications for This Wiki

  • The 5-minute RMSSD measurement minimum is the standard for resting vagal tone assessment
  • "Three Rs" should frame any discussion of HRV biofeedback interventions: we care about resting HRV (structural), reactivity (appropriate vagal withdrawal under challenge), and recovery (speed of return)
  • Respiration rate confound explains why resonance frequency breathing at 6 BPM inflates HRV — this is partly direct vagal stimulation and partly a respiration confound; studies that don't control breathing may overstate the vagal tone improvement

Pages Updated During Ingest

  • concepts/hrv.md — Three Rs framework added; tonic vs. phasic distinction clarified; confound list added
  • practices/resonance-frequency-breathing.md — respiration confound acknowledged

Open Questions

  • What is the minimum valid recording duration for RMSSD in short tasks (< 2 minutes)?
  • The "biological energy reserve" framing from Grossman & Taylor — is this measurable via non-HRV metabolic markers?