An interventional study of Psychoeducational Video Viewing and Heart Rate Variability Biofeedback in Autonomic Nervous System Function and Psychophysiological Regulation, sponsored by University of Haifa. Completed at 1 site in Israel. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by University of Haifa · Not applicable, Interventional, and Basic science
This completed randomized laboratory study investigated the immediate effects of a single 10-minute session of heart rate variability biofeedback (HRV-B) on cardiac activity, forehead physiological signals, and emotional responses in adults.
Heart rate variability reflects changes in the time intervals between heartbeats. HRV biofeedback provides real-time information about heart rhythm patterns and allows individuals to adjust their breathing in response to visual feedback.
Thirty-two adult participants were randomly assigned to one of two groups. Sixteen participants completed HRV biofeedback training using the emWave Pro Plus system, while 16 participants watched educational videos about biofeedback and breathing.
Heart rate variability was measured before, during, and after the intervention. Forehead physiological signals were recorded using hemoencephalography (HEG) before, during, and after the session. Positive and negative affect were assessed using questionnaires completed before and after the intervention.
The purpose was to compare immediate physiological and emotional responses between participants receiving active HRV biofeedback and those receiving psychoeducational information without real-time physiological feedback.
The original ethics-approved research proposal also included a planned non-invasive bioimpedance assessment of systemic inflammation. This component was not implemented, and no inflammation-related measurements were collected.
**Study Background and Objectives**
This randomized, two-arm, single-session laboratory study was conducted at the University of Haifa, Israel, to investigate the immediate cardiac, forehead physiological, and affective responses to heart rate variability biofeedback (HRV-B).
The study examined whether a brief session of HRV biofeedback would produce different physiological and emotional responses compared with a time-matched psychoeducational control condition.
The original research proposal was entitled "Immediate Effects of a Single HRV Biofeedback Session on Cortical Activity and Systemic Inflammation."
The study received approval from the University of Haifa Ethics Committee for Research with Human Participants on December 29, 2025 (Approval No. 518/25). All participants provided written informed consent.
**Participants and Study Design**
The original research proposal planned the recruitment of up to 50 adult participants. Actual enrollment was 32 participants, randomly assigned to two groups using computerized random-number generation:
Each participant attended a single laboratory session lasting approximately 60 minutes.
Participants completed background and personality questionnaires and baseline assessments before the intervention, followed by physiological and psychological measurements during and after the experimental procedure.
**HRV Biofeedback Intervention**
Participants in the intervention group received a brief introduction to slow diaphragmatic breathing.
They then completed 10 minutes of HRV biofeedback using the emWave Pro Plus system (HeartMath), including a visual hot-air-balloon feedback game.
Participants were encouraged to regulate their breathing while observing real-time cardiac coherence feedback. Breathing adjustments were self-paced and guided by the visual feedback.
No individualized resonance-frequency determination, externally prescribed respiratory rate, or fixed inhalation-to-exhalation ratio was implemented.
**Psychoeducational Control Condition**
Participants assigned to the control group watched four consecutive educational videos lasting approximately 10 minutes in total.
The videos introduced general biofeedback principles, heart rate variability biofeedback, diaphragmatic breathing, and variations in breathing patterns.
Control participants did not receive real-time physiological feedback and were not instructed to perform guided biofeedback training during the videos.
**Cardiac Physiological Measurements**
Heart rate variability measurements were obtained using the emWave Pro Plus system with an earlobe photoplethysmographic sensor.
Measurements were collected during three periods:
Recorded variables included heart rate, SDNN, RMSSD, total spectral power, very-low-frequency power, low-frequency power, high-frequency power, LF/HF ratio, and device-derived cardiac coherence.
**Forehead Hemoencephalography Measurements**
Forehead physiological signals were assessed using a BioTekna hemoencephalography (HEG) sensor positioned at Fpz.
Four approximately five-minute measurement periods were obtained:
The exported variables included device-derived rCBO2 measures, within-record signal slope, and the proprietary CFB index.
These indices represent device-derived forehead physiological signals and were not independently validated as direct measurements of neuronal activation or absolute cerebral blood flow.
**Psychological Measurements**
Positive and negative affect were assessed immediately before and after the experimental session using the 10-item short version of the Positive and Negative Affect Schedule (PANAS).
Baseline personality characteristics were assessed using the Ten-Item Personality Inventory (TIPI).
**Originally Planned Inflammation Assessment**
The original ethics-approved research proposal included a non-invasive bioimpedance-based assessment of systemic inflammation using the BioTekna TomEEX system.
This planned measurement component was omitted from the implemented study. No bioimpedance-based inflammation assessments were performed, and no inflammation-related measurements or outcomes were collected or analyzed.
The completed study therefore included cardiac, forehead HEG, and psychological measurements, without an inflammatory measurement component.
**Statistical Analysis and Registration**
The original research proposal described a mixed-design analysis focusing on Group-by-Time interactions, with additional analyses of associations between physiological and psychological variables and possible personality-related differences in intervention responses.
The completed study used repeated-measures analyses to examine group-specific trajectories across the measurement periods. Additional exploratory analyses and post hoc sensitivity analyses were conducted.
The present ClinicalTrials.gov record was created retrospectively, after completion of participant enrollment and data collection. No prospective public trial registration was completed before enrollment.
University of Haifa is the lead sponsor of 105 studies on the registry; 27 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria:Inclusion Criteria:
Exclusion Criteria (as specified in the original approved protocol):
Exclusion Criteria:
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Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Sixteen participants received a single 10-minute session of heart rate variability biofeedback using the emWave Pro Plus system (HeartMath). Following brief instruction in diaphragmatic breathing, participants practiced self-paced breathing while receiving real-time visual cardiac coherence feedback through a hot-air-balloon game. No individualized resonance-frequency assessment or externally prescribed breathing rate was used.
Behavioral: Heart Rate Variability Biofeedback
Sixteen participants watched four consecutive psychoeducational videos lasting approximately 10 minutes in total. The videos addressed biofeedback principles, heart rate variability biofeedback, diaphragmatic breathing, and variations in breathing patterns. Participants received no real-time physiological feedback and were not instructed to perform guided biofeedback training during video viewing.
Behavioral: Psychoeducational Video Viewing
A single 10-minute session consisting of four prerecorded psychoeducational videos about biofeedback, heart rate variability, and breathing. Participants watched the videos without receiving real-time cardiac feedback or guided biofeedback training.
A single 10-minute session of self-paced, visual-feedback-guided heart rate variability biofeedback using the emWave Pro Plus system. Participants received diaphragmatic breathing instructions and practiced adjusting their breathing in response to real-time cardiac coherence feedback displayed through a balloon game.
Change in Mean Forehead Hemoencephalography (HEG) rCBO2 Signal
Change in the mean device-derived rCBO2 signal recorded using a BioTekna HEG sensor at Fpz. Each recording lasted approximately five minutes. The index is not a calibrated measure of neuronal activity or absolute cerebral oxygenation.
Time frame: Baseline (5 minutes), intervention Block 1 (first 5 minutes), intervention Block 2 (second 5 minutes), and immediately post-intervention (5 minutes), within one laboratory visit.
Change in TomEEX-Derived Extracellular Bioimpedance Indices (Not Assessed)
The original ethics-approved study protocol included assessment of extracellular bioimpedance indices using the BioTekna TomEEX system, including ECR, DECW+, BEC, and DECW, as proposed indicators related to systemic inflammation. This component was omitted from the implemented study. No TomEEX assessments were performed, and no inflammation-related outcome data were collected or analyzed.
Time frame: Originally planned at baseline and immediately after the 10-minute intervention, during one laboratory visit. Measurements were not performed.
Change in Heart Rate Variability (SDNN)
Standard deviation of normal-to-normal heart period intervals (SDNN), expressed in milliseconds, derived from emWave Pro Plus earlobe photoplethysmography recordings. Values were assessed across baseline, intervention, and immediate post-intervention periods.
Time frame: Baseline (5 minutes), during the 10-minute intervention, and immediately afterward (5 minutes), within one laboratory visit.
Change in Device-Derived Cardiac Coherence
Normalized cardiac coherence percentage exported by the emWave Pro Plus system. The measure describes the device-derived organization of heart rhythm oscillations during the recording and should not be interpreted as a direct measurement of vagal tone.
Time frame: Baseline (5 minutes), during the 10-minute intervention, and immediately afterward (5 minutes), within one laboratory visit.
Change in Positive Affect Score
Positive Affect score from the 10-item short form of the Positive and Negative Affect Schedule (PANAS). Five items are summed to yield a score ranging from 5 to 25, with higher scores indicating greater positive affect.
Time frame: Immediately before and immediately after the 10-minute intervention, within one laboratory visit.
Change in Negative Affect Score
Negative Affect score from the 10-item short form of the Positive and Negative Affect Schedule (PANAS). Five items are summed to yield a score ranging from 5 to 25, with higher scores indicating greater negative affect.
Time frame: Immediately before and immediately after the 10-minute intervention, within one laboratory visit.
Plan to share: No — There is currently no plan to share individual participant-level data with researchers outside the study team.
No publications or documents are linked to this record.
Ran from Jul 2026 to primary completion in Oct 2026, 3 months.
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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