Physiological correlates of interoception and the effect of heart rate variability biofeedback

Figures

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  FIGURE 1. Schematic overview of the study design. Participants completed two laboratory assessment sessions before (Pre) and after (Post) the 8-week HRV biofeedback intervention. Each session included a resting-state recording followed by the heartbeat counting task. At the pre-intervention session, individual resonant frequency was estimated. The intervention consisted of home-based training conducted five times per week.

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  FIGURE 2. Age-adjusted associations between physiological indices and interoceptive measures, including accuracy in the heartbeat counting task (HBCT) and subscales of the Multidimensional Assessment of Interoceptive Awareness (MAIA). (A) Heatmap of uncorrected partial correlation coefficients controlling for age. (B,C). Scatter plots illustrating the relationships between breathing rate (BR, B) and heart rate (HR, C) and MAIA subscale scores after adjusting for age. Axes represent residuals derived from linear regression models including age, such that values reflect deviations from age-predicted levels. Solid lines indicate least-squares regression fits, with shaded areas representing 95% confidence intervals. Abbreviations: HR heart rate; SDNN standard deviation of heart beat intervals; RMSSD root mean squared of successive heart beat interval differences; BRS baroreflex sensitivity; LFalpha baroreflex gain in low frequency range; RSA respiratory sinus arrhythmia; BR breathing rate; lnLF low frequency power, lnHF high frequency power.

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  FIGURE 3. Follow-up paired-samples t-tests comparing autonomic indices at baseline (Pre) and after the biofeedback intervention (Post). Abbreviations: HR heart rate; SDNN standard deviation of heart beat intervals; BRS baroreflex sensitivity; RSA respiratory sinus arrhythmia; BR breathing rate; LF log-transformed low frequency power of heart rate variability, Ln log‐transformed measure.

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  FIGURE 4. Follow-up paired-samples t-tests comparing subscales of Multivariate Assessment of Interoceptive Awareness (MAIA) at baseline (Pre) and after the biofeedback intervention (Post). Scores on Emotional Awareness and Self-Regulation have been log-transformed.