Parasympathetic Activity Research Articles

Anxiety is related to slower RSA oscillation during stress response and regulation.

Respiratory sinus arrhythmia (RSA), an index of the parasympathetic nervous system activity, has been considered indicative of stress response and emotion regulation. However, the relationship between RSA and anxiety remains inconclusive, partly because previous research has primarily focused on static RSA levels. In this nonclinical sample (N = 75, Mage = 20.89 ± 1.72 SD, 48 males), we used a damped oscillator model to characterize RSA dynamics across 30-s epochs while participants completed the Trier social stress test. Results showed that RSA constantly oscillated during the three periods of TSST (namely Rest, Stress, and Recovery). Importantly, slower RSA oscillation in the Stress period was related to elevated state anxiety, whereas in the Recovery period, it was related to higher trait anxiety. These findings demonstrated the dynamic nature of RSA during the whole course of stress response. Slower RSA oscillation may indicate inflexible and tardy physiological regulation which may give rise to anxiety issues.

The Impact on Autonomic Nervous System Activity during and Following Exercise in Adults: A Meta-Regression Study and Trial Sequential Analysis.

Background and Objectives: Exercise enhances cardiovascular health through various mechanisms, including the modulation of autonomic nervous system activity. This study aimed to systematically examine the impact of exercise on heart rate variability (HRV) in adults during and within one hour after exercise (WHAE). Materials and Methods: A comprehensive literature review was conducted using the MEDLINE, Embase, Cochrane Library, Scopus, and PubMed databases to identify published studies that reported the impact of exercise on autonomic nervous system activity in adults. The studies measured the absolute power of the low-frequency band (0.04-0.15 Hz) to the absolute power of the high-frequency band (0.015-0.4 Hz) (LF/HF ratio) to assess sympathetic activity and the root mean square of successive differences between normal heartbeats (RMSSD) to assess parasympathetic activity. Results: A total of 3329 studies were screened for relevance, and finally, 10 articles that utilized methods for measuring autonomic nervous system activity, such as the LF/HF ratio and RMSSD, covering 292 adult patients, were included for meta-analysis. In the current meta-analysis, we observed a significant decrease in parasympathetic activity during and after exercise, as indicated by RMSSD, compared to pre-exercise levels (mean difference [MD] = -4.96, 95% confidence interval [CI]: -8.00 to -1.91, p = 0.003). However, sympathetic activity after exercise, represented by the LF/HF ratio, showed a borderline significant increase compared to pre-exercise levels (MD = 1.06, 95% CI: -0.01 to 2.12, p = 0.052). The meta-regression model found that factors associated with RMSSD included mean age, male gender, and duration post-exercise. Additionally, the factor associated with the LF/HF ratio was the healthy condition of participants. The trial sequential analysis provided robust evidence of a decrease in RMSSD and an increase in the LF/HF ratio during and WHAE. Conclusions: Given the limitations of the current study, the findings suggest that a significant decrease in parasympathetic activity and a borderline significant increase in sympathetic activity in adults during and WHAE, as confirmed by trial sequential analysis. Meta-regression analysis indicated that parasympathetic activity was negatively associated with participant age and male gender, but positively associated with duration post-exercise. Additionally, increased sympathetic activity was linked to the healthy conditions of participants. This study suggests that exercise might differentially affect autonomic balance in individuals with chronic conditions compared to healthy individuals. This highlights the potential need for tailored exercise interventions to improve autonomic function across different populations.

Deepening insights into cholinergic agents for intraocular pressure reduction: systems genetics, molecular modeling, and in vivo perspectives.

Parasympathetic activation in the anterior eye segment regulates various physiological functions. This process, mediated by muscarinic acetylcholine receptors, also impacts intraocular pressure (IOP) through the trabecular meshwork. While FDA-approved M3 muscarinic receptor (M3R) agonists exist for IOP reduction, their systemic cholinergic adverse effects pose limitations in clinical use. Therefore, advancing our understanding of the cholinergic system in the anterior segment of the eye is crucial for developing additional IOP-reducing agents with improved safety profiles. Systems genetics analyses were utilized to explore correlations between IOP and the five major muscarinic receptor subtypes. Molecular docking and dynamics simulations were applied to human M3R homology model using a comprehensive set of human M3R ligands and 1,667 FDA-approved or investigational drugs. Lead compounds from the modeling studies were then tested for their IOP-lowering abilities in mice. Systems genetics analyses unveiled positive correlations in mRNA expressions among the five major muscarinic receptor subtypes, with a negative correlation observed only in M3R with IOP. Through modeling studies, rivastigmine and edrophonium emerged as the most optimally suited cholinergic drugs for reducing IOP via a potentially distinct mechanism from pilocarpine or physostigmine. Subsequent animal studies confirmed comparable IOP reductions among rivastigmine, edrophonium, and pilocarpine, with longer durations of action for rivastigmine and edrophonium. Mild cholinergic adverse effects were observed with pilocarpine and rivastigmine but absent with edrophonium. These findings advance ocular therapeutics, suggesting a more nuanced role of the parasympathetic system in the anterior eye segment for reducing IOP than previously thought.

Mathematical Modeling of Neuron Using Hodgkin-Huxley Model

The growing rate of mental illnesses has brought the idea to cure anxiety disorders through altering heart rate variability using sympathetic and parasympathetic stimulations. The parasympathetic activity in the sinoatrial node being responsible for arrythmia has been considered in the already existing cardiovascular model. This study presents a mathematical model of a single neuron and simulated its activity for a single burst to be amalgamated in a closed-loop system of the heart and uses heart rate variability as a control variable to treat anxiety disorders and decrease the rate of increasing mental disorders in the world population. The proposed study shows the results that rises from 7mV and goes up to 107mV and then again falls back to 7mV depicting a single burst. These results is being validated by comparing the model of neuron presented in classical Hodgkin-Huxley model using MATLAB.

An emotional distress biomarker in pregnant women: Ultra-short-term heart rate variability

Prenatal emotional distress is common in pregnant women. Altered emotional distress can occur from the very beginning to the end of pregnancy. Heart rate variability (HRV) has recently become considered to be a potentially reliable psychophysiological stress biomarker in adults. In the current study, we evaluated ultra-short-term HRV (1-minute measurement) as a psychophysiological biomarker by examining the association between HRV parameters and self-reported prenatal emotional distress among pregnant women (N = 230) across three trimesters of pregnancy. ResultsPrenatal emotional distress was associated with a lower root mean square of successive differences between normal heartbeats (RMSSD), NN50, and SDNN Index among pregnant women who are in the second trimester. For women in the first and third trimester of pregnancy, prenatal emotional distress was not significantly correlated with any HRV indicators. LimitationsThe cross-sectional nature of our results limits the directional expression and assessment of the relationships, and longitudinal studies that target the recruitment of more pregnant women with subtypes of emotional distress issues are also needed. ConclusionsTime-domain parameters of low HRV (associated with reduced parasympathetic activity) can potentially serve as an efficient psychophysiological biomarker for prenatal emotional distress in the second trimester of pregnancy. However, the time-domain HRV indicators in pregnant women in the first and third trimesters may be affected by other physiological and psychological fluctuations, thus decreasing the HRV biomarker’s efficiency in predicting their prenatal emotional distress.

Effect of Heart Rate Variability Biofeedback Training on Score and Stress Level of Shooting Athletes

This study aimed to explore the impact of a 12-week emWave pro-based heart rate variability biofeedback training followed by a 2-week follow-up on shooters' performance, stress levels, and heart rate variability (HRV). Thirty-six shooters aged 18-24 (18 experimental, 18 control) participated. The experimental group underwent 12 weeks of biofeedback and shooting training, while the control group only received shooting training. Results showed significant improvements in performance, stress levels, and HRV parameters in the experimental group, reflecting enhanced parasympathetic activity. Biofeedback reduced training and competition stress, improving overall performance and stability during matches, emphasizing its effectiveness in shooter training.

Pain-induced effects on the pupillary light response under high and low illumination conditions.

The present study investigated the impact of two different light intensities on the pain-modulated pupillary light response (PLR). Additionally, it aimed to demonstrate parasympathetic and sympathetic influences on PLR parameters in response to pain, as predicted by functional models. A total of 24 participants were included in a randomized, repeated-measures design. The PLR was measured in response to both dark and bright light stimuli within two test cycles. Pain was induced using the cold pressor test (CPT), which involved immersing participants' feet in ice water. PLR measurements were taken during baseline and ice-water immersion within each test cycle. The assessed PLR parameters included initial diameter (INIT), latency (LAT), amplitude (AMP), and re-dilation time (ReDIL25). Along with these parameters, heart rate (HR) and pain ratings were also computed and analyzed. The CPT caused moderate pain in participants, and the resulting PLR parameters were found to be congruent with the expected parasympathetic and sympathetic nervous system activities. Although the luminance of the stimulus did influence PLR parameters, no interaction with pain exposure was found. The results showed that different aspects of pain experienced by an individual, as modulated through the sympathetic and parasympathetic nervous systems, are visible in their pupillary reactions to light. Notably, within the range used in the current study, light intensity did not significantly affect the pain-related PLR effects.

Impact of visual and textural characteristics of street walls on stress recovery

Rapid urbanization increases psychological stress among pedestrians, potentially heightening mental health disorders. This study examines the role of street walls' visual and textural characteristics in stress recovery, using Qingdao as a case study. Virtual reality is employed to simulate five distinct street walls: yellow mortar, brown stone, red brick, green plant, and white mortar. The stress recovery effectiveness of these walls was evaluated through psychological and physiological indicators from 48 young college students. Results indicated that street walls with warm tones, particularly brown stone, significantly aid stress recovery. Psychologically, Restorative Components Scale was highest for brown stone at 1.13. Physiologically, it was linked with notable reductions in diastolic and pulse pressure (decreases of 2.95 mmHg and 2.27 mmHg, respectively), and enhanced parasympathetic activity, as evidenced by the fastest decrease in low frequency/high frequency ratio (LF/HF), and increases in pNN50 and RR (0.14–2.01% and 1.57–11.81 ms, respectively). For urban design, the incorporation of warm-toned materials and natural elements like stone is recommended for their superior restorative benefits.

The Neurophysiological Effects of Craniosacral Treatment on Heart Rate Variability: A Systematic Review of Literature and Meta-Analysis.

Craniosacral treatment (CST) is an osteopathic technique grounded in the assumption that there is an intrinsic, fine movement of the cerebrospinal fluid. This rhythmic movement can be utilized for diagnostic and therapeutic purposes by palpation and manipulation of the skull, spine, and associated connective tissues. Therapeutic benefit is likely due to action on the autonomic nervous system (ANS), specifically through the vagus nerve. Current literature on the neurophysiological effects of CSTis limited, which has contributed to controversy regarding its effectiveness. Heart rate variability (HRV) as a measure of cardiovascular stress and autonomic system activity is thus proposed as a tool to evaluate the neurophysiologic effects of CST. HRV can be analyzed in two different bands, high-frequency (HF) and low-frequency (LF) power associated with a parasympathetic and sympathetic response. In this meta-analysis, we provide a brief introduction to CST, analyze three primary studies, and summarize the therapeutic benefits and pitfalls of this alternative treatment on the ANS. A significant negative HF standardized mean difference after CST was observed; standardized mean difference = -0.46; 95% CI (-0.79,-0.14). No significant effect on LF power was observed. We conclude that CST does provide a moderate short-term increase in parasympathetic activity. These findings suggest that CST may be used to treat patients with an overactive sympathetic state. Further studies should be conducted for comparison against a control group to eliminate the possibility of a placebo effect and to elucidate long-term effects.

Rhinorrhea and watery eyes in infancy and risk of attention-deficit hyperactivity disorder in school-age children.

Increased parasympathetic nervous system (PNS) activity is associated with attention-deficit/hyperactivity disorder (ADHD) inattentive symptoms, but not hyperactive-impulsive symptoms, and may contribute to inattentive subtype etiology. Guided by prior work linking infant rhinorrhea and watery eyes without a cold (RWWC) to PNS dysregulation, we examined associations between infant RWWC and childhood ADHD symptoms in a longitudinal cohort of Black and Latinx children living in the context of economic disadvantage (N=301 youth: 158 females, 143 males). Infant RWWC predicted higher inattentive (relative risk [RR] 2.16, p<.001) but not hyperactive-impulsive (RR 1.53, p=.065) ADHD symptoms (DuPaul scale), administered to caregivers at child age 8-14 years. Stratified analyses revealed that these associations were present in females but not males, who were three times more likely to have higher ADHD current total symptoms if they had infant RWWC than if they did not. Additionally, associations between RWWC and inattention symptoms were observed only in females. RWWC may thus serve as a novel risk marker of ADHD inattentive-type symptoms, especially for females.

More efficient adaptation of cardiovascular response to repeated restraint in spontaneously hypertensive rats: the role of autonomic nervous system

We hypothesized that sympathetic hyperactivity and parasympathetic insuficiency in spontaneously hypertensive rats (SHR) underlie their exaggerated cardiovascular response to acute stress and impaired adaptation to repeated restraint stress exposure compared to Wistar-Kyoto rats (WKY). Cardiovascular responses to single (120 min) or repeated (daily 120 min for 1 week) restraint were measured by radiotelemetry and autonomic balance was evaluated by power spectral analysis of systolic blood pressure variability (SBPV) and heart rate variability (HRV). Baroreflex sensitivity (BRS) was measured by the pharmacological Oxford technique. Stress-induced pressor response and vascular sympathetic activity (low-frequency component of SBPV) were enhanced in SHR subjected to single restraint compared to WKY, whereas stress-induced tachycardia was similar in both strains. SHR exhibited attenuated cardiac parasympathetic activity (high-frequency component of HRV) and blunted BRS compared to WKY. Repeated restraint did not affect the stress-induced increase in blood pressure. However, cardiovascular response during the post-stress recovery period of the 7th restraint was reduced in both strains. The repeatedly restrained SHR showed lower basal heart rate during the dark (active) phase and slightly decreased basal blood pressure during the light phase compared to stress-naive SHR. SHR subjected to repeated restraint also exhibited attenuated stress-induced tachycardia, augmented cardiac parasympathetic activity, attenuated vascular sympathetic activity and improved BRS during the last seventh restraint compared to single-stressed SHR. Thus, SHR exhibited enhanced cardiovascular and sympathetic responsiveness to novel stressor exposure (single restraint) compared to WKY. Unexpectedly, the adaptation of cardiovascular and autonomic responses to repeated restraint was more effective in SHR.

High-rise window views: Evaluating the physiological and psychological impacts of green, blue, and built environments

A growing body of research indicates that visual exposure to nature can enhance mental well-being. However, the impact of such contact through high-rise building windows remains unclear. To address this significant knowledge gap, we utilized aerial drone-captured videos taken from a height of 90 m to present comprehensive visual panoramas encompassing various scenes observed through high-rise building windows. These scenes included three key elements: built structures, greenery, and water bodies. Forty-five participants were randomly assigned to view six conditions in a laboratory setting. Physio-psychological responses to each condition were measured using a portable electroencephalogram device, which continuously recorded brainwaves, and ErgoLAB, which monitored heart rate variability. Additionally, participants completed anxiety level assessments and subjective feelings questionnaires. Our findings revealed that visual contact with all window views produced significantly greater positive effects compared to viewing control or built environments. Among the window views, those featuring green space with water or green space alone elicited the most beneficial outcomes, including increased alpha brainwave activity, enhanced parasympathetic nervous system activation, heightened levels of relaxation and comfort, and lower anxiety levels. The study's findings indicate that high-rise building residents can benefit from 4-min exposure to greenery, either with water or alone, through window views, in promoting mental health. The study emphasizes the importance of considering window views in urban high-rise planning and design to enhance the mental health and well-being of city dwellers.

Immigration stress and maternal sensitivity in a Mexican immigrant sample: The role of parasympathetic activity and familism value.

The present study examined whether immigration stress was related to decreased capacities for psychophysiological stress regulation (as indexed by respiratory sinus arrhythmia [RSA]) and whether lower RSA, in turn, was related to decreased maternal sensitivity. The buffering effect of familism values was also evaluated, such that familism values were expected to minimize associations between immigration stress, RSA, and sensitivity. Data were drawn from a longitudinal study of Mexican immigrant mothers (N = 277; Mage = 28 years). Mothers self-reported immigration stress and familism values, and mothers' resting RSA and sensitivity were assessed during laboratory visits. Higher immigration stress was associated with higher RSA (B = .15, SE = .07, p = .04) but was unrelated to maternal sensitivity. Moreover, links between more immigration stress and higher RSA were more pronounced among mothers who reported stronger familism values (B = .20, SE = .07, p = .003). The present study contributes to our understanding of the sequelae of immigration stress in Mexican immigrant mothers and the cultural resiliency factors that may alter its effects. In contrast to hypotheses, findings suggested that mothers who endorse more immigration stress may also exhibit higher RSA, and links may be more pronounced among those with strong familism values. Further research is needed to advance understanding of resiliency processes that promote family functioning in vulnerable populations. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Assessing the well-being benefits of VR nature experiences on group: Heart rate variability insights from a cross-over study

Recent trends show a rise in stress and psychological disorders, necessitating innovative strategies for recovery. Our study examines the psychophysiological effects of virtual reality (VR) nature, based on the biophilia hypothesis, within real-life group settings. A randomized, acute cross-over design was employed, involving 57 participants who experienced a 10-min session in either a VR nature or a reference room, separated by a 2-min interval. Participants were measured in groups of 7–10 individuals. The VR setup featured a landscape video projected around the participants, creating a captivating 3D environment, whereas the reference room utilized the same space but without the VR elements, maintaining a basic meeting room atmosphere with white walls and a quiet setting. The primary outcome measured was heart rate variability (HRV), complemented by exploratory outcomes including the heart and respiratory rates, and questionnaires on affective well-being, creativity, and sense of belonging. Findings revealed that VR nature exposure resulted in higher HRV and reduced heart rate, indicative of enhanced parasympathetic activity. Participants reported decreased feelings of anxiety and depression, with an increase in comfort, enthusiasm, creativity, and belonging. These results present the VR nature's physiological and psychological benefits, demonstrating its effectiveness in promoting relaxation and recovery in a real-life group setting. In conclusion, the VR nature room can emerge as a versatile tool for stress alleviation and well-being improvement.

Impact of Sleep Apnea on Nocturnal Parasympathetic Activity in Atrial Fibrillation Patients After Catheter Ablation - Implications for Heart Rate Variability Analysis.

The impact of sleep apnea (SA) on heart rate variability (HRV) in atrial fibrillation (AF) patients has not been investigated. Of 94 patients who underwent AF ablation between January 2021 and September 2022, 76 patients who had a nocturnal Holter electrocardiography and polysomnography conducted simultaneously were included in the analysis. A 15-min duration of HRV, as determined by an electrocardiogram during apnea and non-apnea time, were compared between patients with and without AF recurrence at 12 months' postoperatively. Patients had a mean age of 63.4±11.6 years, 14 were female, and 20 had AF recurrence at 12 months' follow-up. The root mean square of the difference between consecutive normal-to-normal intervals (RMSSD, ms) an indicator of a parasympathetic nervous system, was more highly increased in patients with AF recurrence than those without, during both apnea and non-apnea time (apnea time: 16.7±4.5 vs. 13.5±3.3, P=0.03; non-apnea time: 20.9±9.5 vs. 15.5±5.9, P<0.01). However, RMSSD during an apneic state was decreased more than that in a non-apneic state in both groups of patients with and without AF recurrence (AF recurrence group: 16.7±4.5 vs. 20.9±9.5, P<0.01; non-AF recurrence group; 13.5±3.3 vs. 15.5±5.9, P=0.03). Consequently, the effect of AF recurrence on parasympathetic activity was offset by SA. Similar trends were observed for other parasympathetic activity indices; high frequency (HF), logarithm of HF (lnHF) and the percentage of normal-to-normal intervals >50 ms (pNN50). Without considering the influence of SA, the results of nocturnal HRV analysis might be misinterpreted. Caution should be taken when using nocturnal HRV as a predictor of AF recurrence.

The Posterior Insular Cortex is Necessary for Feeding-Induced Jejunal Myoelectrical Activity in Male Rats

The gastrointestinal tract exhibits coordinated muscle motility in response to food digestion, which is regulated by the central nervous system through autonomic control. The insular cortex is one of the brain regions that may regulate the muscle motility. In this study, we examined whether, and how, the insular cortex, especially the posterior part, regulates gastrointestinal motility by recording jejunal myoelectrical signals in response to feeding in freely moving male rats. Feeding was found to induce increases in jejunal myoelectrical signal amplitudes. This increase in the jejunal myoelectrical signals was abolished by vagotomy and pharmacological inhibition of the posterior insular cortex. Additionally, feeding induced a decrease and increase in sympathetic and parasympathetic nervous activities, respectively, both of which were eliminated by posterior insular cortical inhibition. These results suggest that the posterior insular cortex regulates jejunal motility in response to feeding by modulating autonomic tone.

Assessment of Occupational Based Stress and Internal Coherence Related with Quality of Life Through Heartrate Variability (HRV) - A Cross Sectional Study

Background: This study aimed to evaluate occupation-based stress levels and internal coherence in individuals visiting dental clinics of a tertiary care hospital using heart rate variability (HRV) measures. Occupational stress can significantly influence various aspects of quality of life, including emotional health and cardiovascular risks. Objective: The primary objective was to assess the relationship between occupational stress, internal coherence, and quality of life through HRV metrics in a diverse population. Methods: This cross-sectional study was conducted over six months, enrolling 323 voluntary participants aged 18 years and older, irrespective of gender, ethnic background, or occupation. Participants were informed about the study and provided consent one day prior to their participation. HRV recordings were taken for six minutes in a quiet, temperature-controlled room after a 30-minute relaxation period. HRV sensors were applied to either the index finger or earlobe based on the participant's choice. Data were analyzed using emWave Pro Plus and Kubios HRV software. Statistical analysis was performed using SPSS version 25, with numerical variables reported as medians and interquartile ranges and categorical variables as frequencies and percentages. Results: The study comprised 161 males (49.8%) and 162 females (50.2%), with an age range of 18-65 years. Sympathetic activity increased with age, while younger participants exhibited higher parasympathetic activity. The median SDNN was 78.70 ms (IQR 43.8, 148.0) for males and 60.0 ms (IQR 35.1, 132.2) for females. The coherence levels were low across all age groups, and the stress index scores increased with age. Specifically, the stress index was higher in older age groups, with males aged 54-65 years showing a median stress index score of 45.8% in the high-stress category, compared to 17.9% in males aged 18-29 years. Conclusion: The findings highlight the significant impact of occupational stress on HRV and overall well-being. Sympathetic activity increased with age, and stress levels were higher in older participants. These results underscore the importance of work-life balance and stress management strategies to mitigate cardiovascular risks and improve quality of life.

Developing a Five-Minute Normative Database of Heart Rate Variability for Diagnosing Cardiac Autonomic Dysregulation for Patients with Major Depressive Disorder.

Heart rate variability (HRV) is related to cardiac vagal control and emotional regulation and an index for cardiac vagal control and cardiac autonomic activity. This study aimed to develop the Taiwan HRV normative database covering individuals aged 20 to 70 years and to assess its diagnosing validity in patients with major depressive disorder (MDD). A total of 311 healthy participants were in the HRV normative database and divided into five groups in 10-year age groups, and then the means and standard deviations of the HRV indices were calculated. We recruited 272 patients with MDD for cross-validation, compared their HRV indices with the normative database, and then converted them to Z-scores to explore the deviation of HRV in MDD patients from healthy groups. The results found a gradual decline in HRV indices with advancing age in the HC group, and females in the HC group exhibit higher cardiac vagal control and parasympathetic activity than males. Conversely, patients in the MDD group demonstrate lower HRV indices than those in the HC group, with their symptoms of depression and anxiety showing a negative correlation with HRV indices. The Taiwan HRV normative database has good psychometric characteristics of cross-validation.

Exercise Effects on Autonomic Nervous System Activity in Type 2 Diabetes Mellitus Patients over Time: A Meta-Regression Study.

Diabetic autonomic neuropathy is a common complication of type 2 diabetes mellitus (T2DM), especially in patients with long-term, poorly controlled diabetes. This study investigates the effects of exercise on autonomic nervous system activity in T2DM patients over time. A literature review using MEDLINE, Embase, Cochrane Library, Scopus, and PubMed identified studies assessed via heart rate variability. Papers were categorized into three groups: immediate effects (within 60 min), short-term effects (2-3 months), and long-term effects (over 4 months). Nine articles with 161 T2DM patients were included in the meta-analysis. RMSSD changes after exercise were -4.3 (p = 0.227), 8.14 (p < 0.001), and 4.17 (p = 0.002) for the immediate, short-term, and long-term groups, respectively. LF/HF ratio changes were 0.21 (p = 0.264), -3.04 (p = 0.102), and -0.05 (p = 0.006) for the respective groups. Meta-regression indicated age, male gender, and exercise duration were associated with increased RMSSD, with coefficients of 2.36 (p = 0.001), 13.76 (p = 0.008), and 1.50 (p = 0.007), respectively. Age positively correlated with the LF/HF ratio, with a coefficient of 0.049 (p = 0.048). Regular exercise (≥3 times per week) for over 2 months increases parasympathetic activity in T2DM patients, while sympathetic activity decreases significantly after 4 months. Further study is needed to validate these findings.

AI Detection of Human Understanding in a Gen-AI Tutor

Subjective understanding is a complex process that involves the interplay of feelings and cognition. This paper explores how computers can monitor a user’s sympathetic and parasympathetic nervous system activity in real-time to detect the nature of the understanding the user is experiencing as they engage with study materials. By leveraging advancements in facial expression analysis, transdermal optical imaging, and voice analysis, I demonstrate how one can identify the physiological feelings that indicate a user’s mental state and level of understanding. The mental state model, which views understandings as composed of assembled beliefs, values, emotions, and feelings, provides a framework for understanding the multifaceted nature of the emotion–cognition relationship. As learners progress through the phases of nascent understanding, misunderstanding, confusion, emergent understanding, and deep understanding, they experience a range of cognitive processes, emotions, and physiological responses that can be detected and analyzed by AI-driven assessments. Based on the above approach, I further propose the development of Abel Tutor. This AI-driven system uses real-time monitoring of physiological feelings to provide individualized, adaptive tutoring support designed to guide learners toward deep understanding. By identifying the feelings associated with each phase of understanding, Abel Tutor can offer targeted interventions, such as clarifying explanations, guiding questions, or additional resources, to help students navigate the challenges they encounter and promote engagement. The ability to detect and respond to a student’s emotional state in real-time can revolutionize the learning experience, creating emotionally resonant learning environments that adapt to individual needs and optimize educational outcomes. As we continue to explore the potential of AI-driven assessments of subjective understanding, it is crucial to ensure that these technologies are grounded in sound pedagogical principles and ethical considerations, ultimately empowering learners and facilitating the attainment of deep understanding and lifelong learning for advantaged and disadvantaged students.