Adults 18 to 80, any sex, with Heart Rate Variability. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
mPFC-right Amygdala Resting-state Functional Connectivity for Younger Adults (ANOVA)Primary· Time 1 (Baseline), Time 2 (5 weeks)
The strength of resting-state functional connectivity was measured by correlation coefficients. Values represent the correlation of BOLD time-series between mPFC and the right amygdala. Higher values indicate greater connectivity.
Time 1
Group
Value
95% CI
Younger HRV-increase Group
0.104
± 0.105
Younger HRV-decrease Group
0.086
± 0.015
Time 2
Group
Value
95% CI
Younger HRV-increase Group
0.116
± 0.015
Younger HRV-decrease Group
0.090
± 0.015
mPFC-right Amygdala Resting-state Functional Connectivity for Older Adults (ANOVA)Primary· Time 1 (Baseline), Time 2 (5 weeks)
The strength of resting-state functional connectivity was measured by correlation coefficients. Values represent the correlation of BOLD time-series between mPFC and the right amygdala. Higher values indicate greater connectivity.
Time 1
Group
Value
95% CI
Older HRV-increase Group
0.109
± 0.045
Older HRV-decrease Group
0.140
± 0.046
Time 2
Group
Value
95% CI
Older HRV-increase Group
0.125
± 0.046
Older HRV-decrease Group
0.095
± 0.047
mPFC-right Amygdala Resting-state Functional Connectivity for Younger Adults (Post-Pre)Primary· Time 1 (Baseline), Time 2 (5 weeks)
The strength of resting-state functional connectivity between mPFC and the right amygdala was measured by correlation coefficients. The difference in functional connectivity between the two time points (Time 2 - Time 1) was calculated. Higher values indicate greater connectivity at Time 2 than Time 1 (or post- than pre-intervention).
Group
Value
95% CI
Younger HRV-increase Group
0.011
± 0.022
Younger HRV-decrease Group
-0.016
± 0.024
mPFC-right Amygdala Resting-state Functional Connectivity for Older Adults (Post-Pre)Primary· Time 1 (Baseline), Time 2 (5 weeks)
The strength of resting-state functional connectivity between mPFC and the right amygdala was measured by correlation coefficients. The difference in functional connectivity between the two time points (Time 2 - Time 1) was calculated. Higher values indicate greater connectivity at Time 2 than Time 1 (or post- than pre-intervention).
Group
Value
95% CI
Older HRV-increase Group
0.016
± 0.072
Older HRV-decrease Group
-0.045
± 0.046
Emotion Regulation in Younger Adults (Behavior)Secondary· Time 1 (Baseline), Time 2 (5 weeks)
Emotional intensity ratings, which participants reported during the emotion regulation task inside MRI scanner before and after intervention. The ratings ranged from 1 through 4, and 4 represents strongest intensity.
Time 1: down-regulation
Group
Value
95% CI
Younger HRV-increase Group
1.841
± 0.080
Younger HRV-decrease Group
1.822
± 0.085
Time 1: viewing
Group
Value
95% CI
Younger HRV-increase Group
2.073
± 0.084
Younger HRV-decrease Group
2.309
± 0.089
Time 1: up-regulation
Group
Value
95% CI
Younger HRV-increase Group
3.141
± 0.072
Younger HRV-decrease Group
3.271
± 0.076
Time 2: down-regulation
Group
Value
95% CI
Younger HRV-increase Group
1.861
± 0.075
Younger HRV-decrease Group
1.959
± 0.080
Time 2: viewing
Group
Value
95% CI
Younger HRV-increase Group
1.964
± 0.078
Younger HRV-decrease Group
2.427
± 0.083
Time 2: up-regulation
Group
Value
95% CI
Younger HRV-increase Group
3.269
± 0.070
Younger HRV-decrease Group
3.395
± 0.074
Emotion Regulation in Older Adults (Behavior)Secondary· Time 1 (Baseline), Time 2 (5 weeks)
Emotional intensity ratings, which participants reported during the emotion regulation task inside MRI scanner before and after intervention. The ratings ranged from 1 through 4, and 4 represents strongest intensity.
Time 1: down-regulation
Group
Value
95% CI
Older HRV-increase Group
2.059
± 0.085
Older HRV-decrease Group
1.973
± 0.119
Time 1: viewing
Group
Value
95% CI
Older HRV-increase Group
2.586
± 0.096
Older HRV-decrease Group
2.511
± 0.134
Time 1: up-regulation
Group
Value
95% CI
Older HRV-increase Group
3.117
± 0.087
Older HRV-decrease Group
3.022
± 0.121
Time 2: down-regulation
Group
Value
95% CI
Older HRV-increase Group
2.115
± 0.087
Older HRV-decrease Group
2.061
± 0.122
Time 2: viewing
Group
Value
95% CI
Older HRV-increase Group
2.668
± 0.116
Older HRV-decrease Group
2.695
± 0.162
Time 2: up-regulation
Group
Value
95% CI
Older HRV-increase Group
3.279
± 0.069
Older HRV-decrease Group
3.155
± 0.097
Left Amygdala BOLD Activity During Emotion Regulation in Younger AdultsSecondary· Time 1 (Baseline), Time 2 (5 weeks)
We measured percent changes (%) in BOLD activity in the left amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.
Time 1: down-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.032
± 0.022
Younger HRV-decrease Group
0.024
± 0.023
Time 1: viewing
Group
Value
95% CI
Younger HRV-increase Group
0.029
± 0.023
Younger HRV-decrease Group
0.048
± 0.035
Time 1: up-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.107
± 0.026
Younger HRV-decrease Group
0.095
± 0.028
Time 2: down-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.027
± 0.021
Younger HRV-decrease Group
0.021
± 0.022
Time 2: viewing
Group
Value
95% CI
Younger HRV-increase Group
0.018
± 0.019
Younger HRV-decrease Group
-0.020
± 0.021
Time 2: up-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.121
± 0.027
Younger HRV-decrease Group
0.074
± 0.029
Left Amygdala BOLD Activity During Emotion Regulation in Older AdultsSecondary· Time 1 (Baseline), Time 2 (5 weeks)
We measured percent changes (%) in BOLD activity in the left amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.
Time 1: down-regulation
Group
Value
95% CI
Older HRV-increase Group
-0.069
± 0.041
Older HRV-decrease Group
-0.028
± 0.043
Time 1: viewing
Group
Value
95% CI
Older HRV-increase Group
-0.092
± 0.039
Older HRV-decrease Group
-0.006
± 0.040
Time 1: up-regulation
Group
Value
95% CI
Older HRV-increase Group
-0.043
± 0.052
Older HRV-decrease Group
0.067
± 0.053
Time 2: down-regulation
Group
Value
95% CI
Older HRV-increase Group
-0.068
± 0.037
Older HRV-decrease Group
-0.035
± 0.038
Time 2: viewing
Group
Value
95% CI
Older HRV-increase Group
-0.004
± 0.030
Older HRV-decrease Group
-0.013
± 0.031
Time 2: up-regulation
Group
Value
95% CI
Older HRV-increase Group
-0.013
± 0.031
Older HRV-decrease Group
0.036
± 0.032
Right Amygdala BOLD Activity During Emotion Regulation in Younger AdultsSecondary· Time 1 (Baseline), Time 2 (5 weeks)
We measured percent changes (%) in BOLD activity in the right amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.
Time 1: down-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.019
± 0.021
Younger HRV-decrease Group
0.018
± 0.023
Time 1: viewing
Group
Value
95% CI
Younger HRV-increase Group
0.032
± 0.021
Younger HRV-decrease Group
0.039
± 0.022
Time 1: up-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.054
± 0.024
Younger HRV-decrease Group
0.074
± 0.025
Time 2: down-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.076
± 0.026
Younger HRV-decrease Group
0.017
± 0.028
Time 2: viewing
Group
Value
95% CI
Younger HRV-increase Group
0.073
± 0.027
Younger HRV-decrease Group
-0.003
± 0.029
Time 2: up-regulation
Group
Value
95% CI
Younger HRV-increase Group
0.106
± 0.025
Younger HRV-decrease Group
0.068
± 0.027
Right Amygdala BOLD Activity During Emotion Regulation in Older AdultsSecondary· Time 1 (Baseline), Time 2 (5 weeks)
We measured percent changes (%) in BOLD activity in the right amygdala region during emotion down-regulation, viewing, and up-regulation before and after intervention. The viewing condition was used as a baseline during the task. The change is represented by %.
Time 1: down-regulation
Group
Value
95% CI
Older HRV-increase Group
-0.058
± 0.052
Older HRV-decrease Group
-0.014
± 0.053
Time 1: viewing
Group
Value
95% CI
Older HRV-increase Group
0.005
± 0.029
Older HRV-decrease Group
-0.027
± 0.030
Time 1: up-regulation
Group
Value
95% CI
Older HRV-increase Group
0.041
± 0.045
Older HRV-decrease Group
0.062
± 0.047
Time 2: down-regulation
Group
Value
95% CI
Older HRV-increase Group
-0.038
± 0.031
Older HRV-decrease Group
-0.004
± 0.032
Time 2: viewing
Group
Value
95% CI
Older HRV-increase Group
-0.005
± 0.027
Older HRV-decrease Group
0.001
± 0.027
Time 2: up-regulation
Group
Value
95% CI
Older HRV-increase Group
0.006
± 0.038
Older HRV-decrease Group
0.024
± 0.039
Decision-making for Younger Adults at Post Intervention (Behavior)Secondary· one time point: at study completion, which is the end of 5-week training
The decision-making ability was measured by multiple-choice responses during a computer-based task.
Median percentage of acceptance of unfair offers and fair offers were calculated.
A higher percentage of accepted both unfair and fair offers points toward more rational decision-making and likely better emotion regulation.
This task was administered only at post-intervention (but not pre-intervention).
percentage of acceptance of fair offers
Group
Value
95% CI
Younger HRV-increase Group
100
100 – 100
Younger HRV-decrease Group
100
100 – 100
percentage of acceptance of unfair offers
Group
Value
95% CI
Younger HRV-increase Group
33.33
5.56 – 72.22
Younger HRV-decrease Group
33.33
5.72 – 80.21
Decision-making for Younger Adults (fMRI)Secondary· one time point: at study completion, which is the end of 5-week training
We measured percent changes (%) in BOLD activity in the dorsal anterior cingulate cortex and anterior insula during a computer-based decision-making task. Higher values indicate greater activity.
Dorsal anterior cingulate cortex activation
Group
Value
95% CI
Younger HRV-increase Group
0.1073
± 0.0221
Younger HRV-decrease Group
0.0177
± 0.0278
Anterior insula activation
Group
Value
95% CI
Younger HRV-increase Group
0.0740
± 0.0214
Younger HRV-decrease Group
0.0135
± 0.0229
Sponsor's own description
Previous research suggests that heart rate variability (HRV) biofeedback aimed at increasing HRV can reduce anxiety and stress. However, some mental quiescence practices that reduce HRV during the practice sessions also lead to positive emotional outcomes. Thus, it is not obvious that the benefits of HRV-biofeedback accrue due to increasing HRV during the session. An alternative possibility is that the benefits arise from engaging prefrontal control over heart rate. In this study, the investigators will test two possible mechanisms of the effects of HRV on emotional health by comparing two groups. In one group, participants will be asked to engage in daily training to decrease HRV using the HRV biofeedback device. In the other group, participants will be asked to engage in daily training to increase HRV using the HRV biofeedback device. This will allow analyses to pit two possible mechanisms against each other:
1. Mechanism 1: engaging prefrontal control over heart rate is the critical factor that allows HRV biofeedback to help improve well-being. In this case, well-being should increase over time in both groups, as both training should engage prefrontal cortex to implement self-directed control over heart rate. Strengthening prefrontal control mechanisms may help improve emotion regulation in everyday life.
2. Mechanism 2: increased HRV during the training sessions leads to greater functional connectivity among brain regions associated with emotion regulation during the high HRV state. In this case, improved well-being would be specifically associated with having time each day during which there were very high HRV states, and so improved well-being should be seen only in the group in which participants get biofeedback to increase HRV.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
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Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
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Sponsor: as reported to ClinicalTrials.gov by University of Southern California
Last refreshed: 23 July 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03458910.