BACKGROUND: Wearable technology is increasingly used in clinical practice and research to monitor functional gastrointestinal symptoms and mental health.
OBJECTIVE: This article explores the potential of wearable sensors to enhance the understanding of the autonomic nervous system (ANS), particularly its role in linking psychological and gastrointestinal function. The ANS, facilitates brain-gut communication and is responsive to psychosocial conditions. It is implicated in disorders related to psychological stress and gut-brain interaction. Wearable technology enables tracking of the ANS in daily life, offering complementary and alternative methods from traditional lab-based measures. This review places focus on autonomic metrics such as respiratory sinus arrhythmia, vagal efficiency, and electrodermal activity as well as self-reports of autonomic symptoms.
CONCLUSIONS: Potential applications include use of wearable sensors for tracking autonomic activity in disorder of gut-brain interaction such as cyclic vomiting syndrome, in which ANS dysregulation may be triggered by psychosocial factors. Considerations for data interpretation and contextualization are addressed, acknowledging challenges such as situational confounders of ANS activity and accuracy of wearable devices.

The significance of physiological regulation in relation to behavioral and emotional regulation is well documented, but primarily in economically advantaged contexts. Few studies have been conducted in low- and middle-income countries. We investigated the feasibility and reliability of measuring autonomic nervous system (ANS) activity and behavior during challenge tasks in 30 children aged 8-10 years in Ghana during two visits, 1 week apart. Completeness of ANS data ranged from 80% to 100% across all tasks. There was low-to-moderate test-retest reliability of video mood induction (VMI) emotion ratings and balloon analog risk task (BART) pumps (r = 0.34-0.52). VMI elicited higher targeted emotion ratings in Visit 2 than Visit 1. Respiratory sinus arrhythmia (RSA) was higher, and pre-ejection period (PEP) was longer at Visit 2 than Visit 1 for baseline and both tasks. RSA was higher at baseline than during the VMI anger scene at Visit 1, whereas PEP was shorter at baseline than during all VMI emotion scenes at Visit 2. RSA was higher at baseline than during BART at both visits. In conclusion, ANS data collection within evocative and arousing challenge tasks was feasible in Ghana, and the tasks were generally reliable and effective in eliciting target emotions and risk-taking behavior in this sample.

Family environment, emotion regulation and biological sensitivity have been shown to be associated with adolescents\' externalizing problem behaviours. However, findings regarding respiratory sinus arrhythmia (RSA) reactivity are mixed and sometimes contradictory. This study aims to clarify the roles of RSA reactivity and anger regulation in the relationship between negative family expressiveness (NFE) and adolescents\' externalizing behaviour by measuring RSA reactivity during the Parent-Adolescent Interaction Task (PAIT), designed to simulate a naturalistic negative family environment. In this study, 125 Chinese adolescents (M = 13.95 years, SD = 0.95; 48% male) completed questionnaires assessing negative family expressiveness, anger regulation and externalizing problems. Additionally, we collected electrocardiogram and respiration data during both the resting period and a 10-min PAIT. Results showed that anger regulation mediated the relationship between NFE and externalizing problem behaviours. Moreover, adolescents\' RSA reactivity moderated this mediation effect, even after controlling for baseline RSA. Greater RSA suppression potentially indicated greater susceptibility, with the relationship between NFE and anger regulation being more pronounced in adolescents with greater RSA suppression compared to those with lesser RSA suppression. These findings highlight the importance of considering physiological systems, especially within the context of adverse family environments, when studying the relationships with externalizing problems.

Slow and deep breathing (SDB) is a relaxation technique that can increase vagal activity. Respiratory sinus arrhythmia (RSA) serves as an index of vagal function usually quantified by the high-frequency power of heart rate variability (HRV). However, the low breathing rate during SDB results in deviations when estimating RSA by HRV. Besides, the impact of the inspiration-expiration (I: E) ratio and guidelines ways (fixed breathing rate or intelligent guidance) on SDB is not yet clear. In our study, 30 healthy people (mean age = 26.5 years, 17 females) participated in three SDB modes, including 6 breaths per minute (bpm) with an I:E ratio of 1:1/ 1:2, and intelligent guidance mode (I:E ratio of 1:2 with guiding to gradually lower breathing rate to 6 bpm). Parameters derived from HRV, multimodal coupling analysis (MMCA), Poincaré plot, and detrended fluctuation analysis were introduced to examine the effects of SDB exercises. Besides, multiple machine learning methods were applied to classify breathing patterns (spontaneous breathing vs. SDB) after feature selection by max-relevance and min-redundancy. All vagal-activity markers, especially MMCA-derived RSA, statistically increased during SDB. Among all SDB modes, breathing at 6 bpm with a 1:1 I:E ratio activated the vagal function the most statistically, while the intelligent guidance mode had more indicators that still significantly increased after training, including SDRR and MMCA-derived RSA, etc. About the classification of breathing patterns, the Naive Bayes classifier has the highest accuracy (92.2%) with input features including LFn, CPercent, pNN50, [Formula: see text], SDRatio, [Formula: see text], and LF. Our study proposed a system that can be applied to medical devices for automatic SDB identification and real-time feedback on the training effect. We demonstrated that breathing at 6 bpm with an I:E ratio of 1:1 performed best during the training phase, while intelligent guidance mode had a more long-lasting effect.

UNASSIGNED: People living with HIV (PLWH) experience high rates of childhood trauma exposure, which is a significant risk factor for the development of posttraumatic stress disorder (PTSD). Because Black Americans living in urban environments are exposed to high levels of trauma, suffer from chronic PTSD, and are at increased risk for HIV infection, it is important to understand how HIV status interacts with childhood maltreatment to influence PTSD symptom severity and underlying psychophysiology.
UNASSIGNED: The current cross-sectional study assessed whether HIV status interacts with childhood maltreatment to influence PTSD symptom severity and heart rate variability during a dark-enhanced startle (DES) task in 88 Black women with (n=30) and without HIV (n=58).
UNASSIGNED: HIV was associated with greater PTSD symptom severity only in women with low levels of childhood maltreatment (p=.024). Startle potentiation during DES was highest in women living without HIV and with high childhood maltreatment (p=.018). In women who had experienced low levels of childhood maltreatment, respiratory sinus arrhythmia (RSA) was lower during the dark phase of DES in women living without HIV than women living with HIV (WLWH), (p=.046). RSA during the light phase of DES was lower in WLWH than in women living without HIV (p=.042).
UNASSIGNED: In the current sample of Black women, HIV status was associated with PTSD symptom severity in a manner dependent on level of childhood maltreatment, suggesting that HIV status may be an important factor to consider for behavioral and pharmacological treatment strategies for PTSD. Additionally, HIV status is associated with lower percent potentiation to darkness and lower RSA during the light phase of DES, suggesting physiological mechanisms by which HIV may contribute to PTSD symptoms in individuals exposed to low levels of childhood maltreatment.

This study examined the stability of Attachment Script Assessment (ASA) deactivation, hyperactivation, and anomalous content and their significance for parenting outcomes in mothers (Mage = 31 years; 78% White/European American) and 6-month-old infants. Comparable to ASA secure base script knowledge (SBSK), mothers\' ASA deactivation, hyperactivation, and anomalous content were significantly, moderately stable over two years (r\'s = .40 - .43). Mothers\' ASA hyperactivation and anomalous content were associated with greater maternal intrusiveness, whereas ASA deactivation was associated with greater detachment and less intrusiveness. Only ASA anomalous content was associated with lower maternal sensitivity. Mothers\' ASA deactivation was associated with less dynamic change in respiratory sinus arrhythmia during the Still-Face Procedure-reflective of limited mobilization of physiological resources to support responding to infants. Findings support the validity of ASA deactivation, hyperactivation, and anomalous content scripts, and demonstrate their utility in examining adult attachment stability and predictive significance for parent-child outcomes.

Both parasympathetic nervous system regulation and receipt of social support from close relationships contribute to prosocial development, although few studies have examined their combined influences in adolescence and particularly within racially and ethnically minoritized populations. In this longitudinal study of 229 U.S. Mexican-origin adolescents (48% female-identifying), youths reported on receipt of social support from family and friends from 10 to 16 years, had their baseline respiratory sinus arrhythmia (RSA) measured at 17 years, reported their prosocial behavior and completed the Mind in the Eyes test to assess cognitive empathy at 17 and 19 years, and reported their prosocial civic behavior (i.e., community activity) at 19 years. Family social support predicted prosocial behavior at 17 years, and friend social support predicted prosocial civic behavior at 19 years. Compared to youths with lower or higher baseline RSA, youths with moderate RSA reported more prosocial civic behavior, had greater cognitive empathy, and tended to report more general prosocial behavior at 19 years. The quadratic association between baseline RSA and cognitive empathy was stronger for youths with greater family social support. These findings are the first to extend the evidence that moderate baseline parasympathetic nervous system activity supports prosocial development into late adolescence and with the U.S. Mexican-origin community, and these findings address calls for more integrative biopsychosocial studies of prosociality. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

OBJECTIVE: Seizures are characterized by periictal autonomic changes. Wearable devices could help improve our understanding of these phenomena through long-term monitoring. In this study, we used wearable electrocardiogram (ECG) data to evaluate differences between temporal and extratemporal focal impaired awareness (FIA) seizures monitored in the hospital and at home. We assessed periictal heart rate, respiratory rate, heart rate variability (HRV), and respiratory sinus arrhythmia (RSA).
METHODS: We extracted ECG signals across three time points - five minutes baseline and preictal, ten minutes postictal - and the seizure duration. After automatic Rpeak selection, we calculated the heart rate and estimated the respiratory rate using the ECG-derived respiration methodology. HRV was calculated in both time and frequency domains. To evaluate the influence of other modulators on the HRV after removing the respiratory influences, we recalculated the residual power in the high-frequency (HF) and low-frequency (LF) bands using orthogonal subspace projections. Finally, 5-minute and 30-second (ultra-short) ECG segments were used to calculate RSA using three different methods. Seizures from temporal and extratemporal origins were compared using mixed-effects models and estimated marginal means.
RESULTS: The mean preictal heart rate was 69.95 bpm (95 % CI 65.6 - 74.3), and it increased to 82 bpm, 95 % CI (77.51 - 86.47) and 84.11 bpm, 95 % CI (76.9 - 89.5) during the ictal and postictal periods. Preictal, ictal and postictal respiratory rates were 16.1 (95 % CI 15.2 - 17.1), 14.8 (95 % CI 13.4 - 16.2) and 15.1 (95 % CI 14 - 16.2), showing not statistically significant bradypnea. HRV analysis found a higher baseline power in the LF band, which was still significantly higher after removing the respiratory influences. Postictally, we found decreased power in the HF band and the respiratory influences in both frequency bands. The RSA analysis with the new methods confirmed the lower cardiorespiratory interaction during the postictal period. Additionally, using ultra-short ECG segments, we found that RSA decreases before the electroclinical seizure onset. No differences were observed in the studied parameters between temporal and extratemporal seizures.
CONCLUSIONS: We found significant increases in the ictal and postictal heart rates and lower respiratory rates. Isolating the respiratory influences on the HRV showed a postictal reduction of respiratory modulations on both LF and HF bands, suggesting a central role of respiratory influences in the periictal HRV, unlike the baseline measurements. We found a reduced cardiorespiratory interaction during the periictal period using other RSA methods, suggesting a blockade in vagal efferences before the electroclinical onset. These findings highlight the importance of respiratory influences in cardiac dynamics during seizures and emphasize the need to longitudinally assess HRV and RSA to gain insights into long-term autonomic dysregulation.

Although many previous studies have reported the relationship between hypersensitivity and vagal function in children, the relationship in adults is unclear. This study investigates the relationship between hypersensitivity and vagal function, discomfort to sensory stimuli, and daily mood states in healthy adults. Using a questionnaire, 39 healthy adults were divided into hypersensitivity and control groups. We compared the baseline respiratory sinus arrhythmia (RSA), reflecting vagal tone and reactivity, subjective discomfort to sensory stimuli, and daily mood status between groups. Those in the hypersensitivity group had significantly lower baseline RSA and were more likely to experience greater RSA variability and discomfort during exposure to sensory stimuli than the control group. We found no significant difference between groups in daily mood status. These findings suggest that vagal function is an important marker of hypersensitivity in healthy adults.
Relationships Among Hypersensitivity, Parasympathetic Function, and Mood States in AdultsPrevious studies in children have reported many associations between sensory characteristics, such as hypersensitivity to sensory stimuli, and parasympathetic function, but the association in adults is not clear. This study divided 39 healthy adults into a hypersensitivity group and a control group and compared their parasympathetic function, discomfort to sensory stimuli, and daily mood. We found that the hypersensitivity group had significantly lower baseline parasympathetic function and tended to experience greater fluctuations in parasympathetic activity and discomfort during sensory stimulation than the control group. However, we found no significant difference in daily mood between the groups. This suggests that parasympathetic function is an important marker of hypersensitivity in healthy adults. This may help therapists support those with hypersensitivity. Future research is needed in clinical practice.

This Committee Report provides methodological, interpretive, and reporting guidance for researchers who use measures of heart rate (HR) and heart rate variability (HRV) in psychophysiological research. We provide brief summaries of best practices in measuring HR and HRV via electrocardiographic and photoplethysmographic signals in laboratory, field (ambulatory), and brain-imaging contexts to address research questions incorporating measures of HR and HRV. The Report emphasizes evidence for the strengths and weaknesses of different recording and derivation methods for measures of HR and HRV. Along with this guidance, the Report reviews what is known about the origin of the heartbeat and its neural control, including factors that produce and influence HRV metrics. The Report concludes with checklists to guide authors in study design and analysis considerations, as well as guidance on the reporting of key methodological details and characteristics of the samples under study. It is expected that rigorous and transparent recording and reporting of HR and HRV measures will strengthen inferences across the many applications of these metrics in psychophysiology. The prior Committee Reports on HR and HRV are several decades old. Since their appearance, technologies for human cardiac and vascular monitoring in laboratory and daily life (i.e., ambulatory) contexts have greatly expanded. This Committee Report was prepared for the Society for Psychophysiological Research to provide updated methodological and interpretive guidance, as well as to summarize best practices for reporting HR and HRV studies in humans.