Does contingent biofeedback improve cardiac interoception? A preregistered replication of Meyerholz, Irzinger, Withöft, Gerlach, and Pohl (2019) using the heartbeat discrimination task in a randomised control trial

Body listening in the link between symptoms and self-care management in cardiovascular disease: A cross-sectional correlational descriptive study

OBJECTIVE

The aim of this study was to quantify relationships among symptoms, interoceptive sensibility (i.e. the conscious level of sensing, interpreting and integrating signals from the body), and self-care management behaviors (i.e. the response to symptoms when they occur) among adults with cardiovascular disease. We hypothesized that better interoceptive sensibility would increase the positive behavior-driving effects of symptoms on self-care management.

METHODS

Adult patients with cardiovascular disease who experienced recent symptoms were recruited to participate in this cross-sectional correlational descriptive study. Patient-Reported Outcomes Measurement Information System measures were used to capture dyspnea, pain interference, fatigue, sleep disturbances, nausea and vomiting, anxiety and depressive symptoms. Interoceptive sensibility was measured using the Multidimensional Assessment of Interoceptive Awareness Version 2. The Self-Care of Chronic Illness Inventory was used to measure self-care management. Network analysis was used to identify domains of interoceptive sensibility that were most central. Linear regression with interaction terms was used to test the moderating effect of interoceptive sensibility on the relationship between symptoms and self-care management.

RESULTS

The age of participants in the sample (n = 387) ranged from 18 to 88 years, a slight majority (53.5 %) were female, and a majority were Caucasian (66.4 %) or African American (32.0 %). Hypertension was the most common disorder (n = 238 (61.5 %)), followed by rhythm disorders (n = 124 (32.0 %)), coronary artery disease (n = 94 (24.3 %)), heart failure (n = 89 (23.0 %)), valve disease (n = 69 (17.8 %)), stroke (n = 62 (16.0 %)) and peripheral vascular disease (n = 49 (12.7 %)). Based on network analysis, body listening (i.e. active listening to the body for insights) was the most central interoceptive domain, and distracting (i.e. tendency to ignore or distract oneself from sensations of discomfort) was the least central. Noticing (i.e. greater awareness of body sensations), distracting, and body listening were significant in moderating relationships between dyspnea, sleep disturbances and anxiety and the outcome of self-care management behaviors (all p < 0.001). Better noticing and body listening were associated with better self-care management across symptoms, whereas ignoring or distracting oneself from discomfort was associated with worse self-care management behaviors.

CONCLUSION

Among adults with cardiovascular disease, interventions designed to augment the identified interoceptive sensibility domains like body listening, and mitigate the tendency to ignore or distract oneself from discomfort may support adults with cardiovascular disease through the development of future interventions that optimize patient behaviors in response to symptoms when they occur.

High-intensity interval training (HIIT) and slow breathing interventions alleviate premature ejaculation (PE) symptoms

Background

Physical exercise may alleviate premature ejaculation symptoms, a prevalent male sexual dysfunction linked to a series of negative outcomes for men and their partners.

Objective

We investigated the effectiveness of high-intensity interval training (HIIT) and slow breathing interventions on premature ejaculation symptoms and their relation to autonomic activity and attention regulation.

Method

Chinese adult men (N = 76, M = 21.89, SD = 3.32) with premature ejaculation completed one of the two-week interventions in their homes or as participants in a normal breathing control group; they reported their age, height, weight, physical activity level, premature ejaculation symptoms, and attention regulation. In the HIIT group, 26 participants engaged in a 7-minute HIIT each day. In the slow breathing group, 25 participants performed 7-minute slow breathing exercises per day while the 25 participants in the normal breathing group similarly performed normal breathing exercises. All participants measured their heart rate once before and five times (with one-minute intervals) after the intervention. When participants had penile-vaginal sex with their partners, they measured their heart rate once after ejaculation.

Results

Time × Intervention interaction was significant with lower levels of premature ejaculation symptoms on Days 12, 13, and 14 in the HIIT group (M ± SD = 16.19 ± 3.45, 15.96 ± 3.43, and 15.15 ± 3.62) compared to the normal breathing group (M ± SD = 17.68 ± 3.06, 17.68 ± 3.15, and 17.44 ± 3.25). Higher levels of attention regulation were associated with fewer premature ejaculation symptoms. We also found that a larger increase in heart rate from resting to after sex was associated with fewer premature ejaculation symptoms.

Conclusion

Compared to the control group, the efficacy of two weeks of HIIT exercise in mitigating PE symptoms suggests its potential as a novel treatment for PE.

The effect of 10-week long yoga training on interoceptive abilities: cross-sectional and longitudinal investigation of cardiac and gastric accuracy

Based on their characteristics, it is likely that mind-body techniques develop interoception, the perception of bodily state. Nevertheless, findings on mindfulness, meditation, yoga, and body scan techniques are inconclusive. Additionally, the methodological scope is not exhaustive, neither in terms of the intervention nor the applied measure of interoception. This study investigated for the first time the effect of regular yoga training on cardiac and gastric perceptual ability (measured with the mental heartbeat tracking task and the water load task, respectively). With the involvement of 90 female university students (yoga group n = 57, control group n = 33) we did not find any connection between baseline heartbeat perception score and gastric fullness. Moreover, the applied 10-week-long regular yoga training did not develop any of the measured interoceptive abilities. We conclude that yoga might develop other abilities than these specific sensations. Very probably, the measured cardiac and gastric perceptual abilities do not represent bodily sensations in general. It would be worth to investigate, however, the effect of longer yoga training on interoception.

The misjudgment of interoceptive awareness: Systematic overrating of interoceptive awareness among individuals with lower interoceptive metacognitive skills

Knowing when perceiving inner bodily signals better and when perceiving them worse is a health relevant but understudied dimension of interoception. Therefore, the present study assessed interoceptive metacognition (IMC) as the skill to adequately monitor interoceptive accuracy in the cardiac domain. We used the Graz Ambulatory Interoception task (GRAIT), which applied two intervals of the heartbeat tracking task 12 times a day for 3 days in total to n = 66 participants. We assessed IMC as the relative correspondence between interoceptive accuracy and the subjective confidence ratings. We found that 6 % of the total IMC variance was due to person, which was assessed reliable (RKRn=0.81). Furthermore, the between-person variation of IMC was negatively associated with the MAIA (especially attention regulation and self-regulation). People who believe that they are aware of their interoceptive experiences (MAIA) showed lower IMC. This study advocates the assessment of interoception in everyday life.

Interoceptive ability moderates the effect of physiological reactivity on social judgment

Social judgments-that others are kind or cruel, well intentioned, or conniving-can ease or disrupt social interactions. And yet a person's internal state can alter these judgments-a phenomenon known as affective realism. We examined the factors that contribute to, and mitigate, affective realism during a stressful interview. Using data collected between 2015 and 2019, we hypothesized and found that individuals' ability (N = 161; 57.6% female; 57.6% European American, 13.6% African American, 13.6% Asian American, 6.4% Latinx, 6.0% biracial, and 2.8% that identified with none or 1 + of the races presented; Mage = 19.20 years) to accurately perceive their own internal sensations (i.e., heartbeats) influenced whether they attributed their own heightened stress reactions (i.e., sympathetic nervous system reactivity) to the behavior of two impassive interviewers. Participants who were poor heartbeat detectors perceived their interviewers as less helpful, polite, or professional, and more apathetic, judgmental, and aggressive when experiencing heightened levels of cardiovascular sympathetic nervous system reactivity during their interview. Being aware of one's internal state may be one pathway to reducing bias in social perceptions in circumstances where such biases may lead us astray. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effect of subconscious changes in bodily response on thought shifting in people with accurate interoception

Our thought states shift from one state to another from moment to moment. The relationship between the thought shifting and bodily responses is yet to be directly examined. This exploratory study examined the influence of cardiovascular reactivity and interoception-sensing an internal bodily state-on the shifting of thought states. Participants (N = 100, 70 women) completed two tasks: the heartbeat counting task (HCT) and the vigilance task (VT). We assessed their interoceptive accuracy through their performance on the HCT. The VT was a simple sustained attention task in which participants pressed a key when the target stimulus appeared and were asked to report their thoughts. We presented subliminal vibration stimuli to induce alterations in heart rate (i.e., vibration block). Results showed that participants with higher interoceptive accuracy reported more continuation of self-referential thought (about past episodes and future plans regarding themselves) during the vibration block than did those with lower interoceptive accuracy. These results suggest that individuals with higher interoceptive accuracy are more likely to be influenced by their subliminal bodily response, resulting in divergent attention from the task and intermittent self-referential thought.

Complexity and Entropy in Physiological Signals (CEPS): Resonance Breathing Rate Assessed Using Measures of Fractal Dimension, Heart Rate Asymmetry and Permutation Entropy

BACKGROUND

As technology becomes more sophisticated, more accessible methods of interpretating Big Data become essential. We have continued to develop Complexity and Entropy in Physiological Signals (CEPS) as an open access MATLAB® GUI (graphical user interface) providing multiple methods for the modification and analysis of physiological data.

METHODS

To demonstrate the functionality of the software, data were collected from 44 healthy adults for a study investigating the effects on vagal tone of breathing paced at five different rates, as well as self-paced and un-paced. Five-minute 15-s recordings were used. Results were also compared with those from shorter segments of the data. Electrocardiogram (ECG), electrodermal activity (EDA) and Respiration (RSP) data were recorded. Particular attention was paid to COVID risk mitigation, and to parameter tuning for the CEPS measures. For comparison, data were processed using Kubios HRV, RR-APET and DynamicalSystems.jl software. We also compared findings for ECG RR interval (RRi) data resampled at 4 Hz (4R) or 10 Hz (10R), and non-resampled (noR). In total, we used around 190-220 measures from CEPS at various scales, depending on the analysis undertaken, with our investigation focused on three families of measures: 22 fractal dimension (FD) measures, 40 heart rate asymmetries or measures derived from Poincaré plots (HRA), and 8 measures based on permutation entropy (PE).

RESULTS

FDs for the RRi data differentiated strongly between breathing rates, whether data were resampled or not, increasing between 5 and 7 breaths per minute (BrPM). Largest effect sizes for RRi (4R and noR) differentiation between breathing rates were found for the PE-based measures. Measures that both differentiated well between breathing rates and were consistent across different RRi data lengths (1-5 min) included five PE-based (noR) and three FDs (4R). Of the top 12 measures with short-data values consistently within ± 5% of their values for the 5-min data, five were FDs, one was PE-based, and none were HRAs. Effect sizes were usually greater for CEPS measures than for those implemented in DynamicalSystems.jl.

CONCLUSION

The updated CEPS software enables visualisation and analysis of multichannel physiological data using a variety of established and recently introduced complexity entropy measures. Although equal resampling is theoretically important for FD estimation, it appears that FD measures may also be usefully applied to non-resampled data.

The Hybrid Excess and Decay (HED) model: an automated approach to characterising changes in the photoplethysmography pulse waveform

Photoplethysmography offers a widely used, convenient and non-invasive approach to monitoring basic indices of cardiovascular function, such as heart rate and blood oxygenation. Systematic analysis of the shape of the waveform generated by photoplethysmography might be useful to extract estimates of several physiological and psychological factors influencing the waveform. Here, we developed a robust and automated method for such a systematic analysis across individuals and across different physiological and psychological contexts. We describe a psychophysiologically-relevant model, the Hybrid Excess and Decay (HED) model, which characterises pulse wave morphology in terms of three underlying pressure waves and a decay function. We present the theoretical and practical basis for the model and demonstrate its performance when applied to a pharmacological dataset of 105 participants receiving intravenous administrations of the sympathomimetic drug isoproterenol (isoprenaline). We show that these parameters capture photoplethysmography data with a high degree of precision and, moreover, are sensitive to experimentally-induced changes in interoceptive arousal within individuals. We conclude by discussing the possible value in using the HED model as a complement to standard measures of photoplethysmography signals.

The Effects of a 3-Week Heartbeat Perception Training on Interoceptive Abilities

Recent studies showed promising short-term effects of heartbeat perception training on interoceptive abilities. Research on the effects of heartbeat perception training on interoceptive abilities over time is sparse. Therefore, the aim of this study was to examine the short-term effects and the effects of a 3-week heartbeat perception training over time on interoceptive abilities, namely, cardiac interoceptive accuracy (IAc) and interoceptive sensibility (IS). A total of 40 healthy participants were randomized to the intervention group (n = 20) or the control group (n = 20). The intervention group conducted three cardiac biofeedback sessions (one per week) at the laboratory, whereas the control group watched a documentary instead. Interoceptive abilities were assessed via the heartbeat perception task (IAc) and confidence ratings (IS) at baseline, after each laboratory session, and 1 week after the last session (post-measurement). IAc was significantly increased in the intervention group compared to the control group after the first training session (short-term effect). There were no significant improvements in IS due to the first session, and neither on IAc nor IS over time. Descriptive trends of improved interoceptive abilities over time were found in both groups. Single session of heartbeat perception training seems to be a promising approach to improve IAc. Future research should further investigate the long-term effects of diverse heartbeat perception training varying in frequency and intensity of the training sessions in diverse samples aiming to improve interoceptive abilities.

Short-term fasting induced changes in HRV are associated with interoceptive accuracy: Evidence from two independent within-subjects studies

Previous research suggested increased cardiac interoceptive accuracy after 24-h food-deprivation by means of the heartbeat tracking task. The present study investigated if 16-h of voluntary fasting shows similar effects and whether changes in interoceptive accuracy are accompanied by changes in autonomic function. In two independent within-subjects studies two measures of interoceptive accuracy, the heartbeat tracking task and the heartbeat discrimination task were applied. In study 1 (n = 24) and study 2 (n = 72) vagally-mediated HRV increases and heart rate decreases were observed. Stronger effects of fasting on vagally-mediated HRV went along with a higher interoceptive accuracy increase in the heartbeat tracking task. Furthermore, the fasting associated changes in interoceptive accuracy in both tasks were significantly associated, suggesting that these tasks are suitable to track changes in cardiac interoception. Taken together, fasting of 16-h might be suitable to increase participants' parasympathetic efference, thereby facilitating interoception.

Cardiovascular mechanisms of interoceptive awareness: Effects of resonance breathing

Interoception, the ability to perceive internal bodily sensations, and heart rate variability (HRV) share common physiological pathways, including the baroreflex feedback loop. The baroreflex can be activated by resonance breathing, wherein respiration is paced at 6 times per minute (0.1 Hz), eliciting immediate physiological changes and longer-term therapeutic responses. This registered report characterizes baroreflex functioning as a cardiac mechanism of interoception in a two-session study (n = 67). The heartbeat discrimination task was used to obtain indices of interoceptive accuracy, sensibility and metacognition. Baroreflex functioning was measured as HRV at 0.1 Hz and baroreflex sensitivity (BRS); high frequency (HF) HRV was calculated as a control. Cardiovascular indices were measured at baseline and during active and control paced breathing after which changes in interoception were measured. The first hypothesis was that baseline baroreflex functioning would predict individual differences in interoceptive awareness. The second hypothesis was that resonance breathing would increase participants' ability to detect their own heartbeats, and that this effect would be mediated by increases in 0.1 Hz HRV and BRS. Data were collected upon in principle acceptance of the manuscript. We found a negative relationship of interoceptive accuracy with baseline HF HRV and BRS, and a positive relationship between metacognitive interoception and 0.1HZ HRV, BRS and HF HRV. We found that changes in 0.1 Hz HRV and BRS during resonance breathing positively correlate with increases in interoceptive accuracy. Our results show that the extent to which breathing recruits the resonant properties of the cardiovascular system can facilitate the conscious perception of participants' heartbeats. We interpret this as an increase in vagal afferent signaling and baroreflex functioning following resonance breathing. We put forward an alternative explanation that HRV modulation can reduce interoceptive prediction errors, facilitating the conscious perception of interoceptive signals, and consider the role of resonance breathing on mental health from an interoceptive inference perspective.