The Effects of a Prenatal Mindfulness Intervention on Infant Autonomic and Behavioral Reactivity and Regulation.

OBJECTIVE: Maternal health and wellness during pregnancy are associated with long-term health outcomes in children. The current study examined whether infants of women who participated in a mindfulness-based intervention during pregnancy that reduced levels of stress and depression, increased physical activity, and improved glucose tolerance differed on biobehavioral markers of psychopathological and physical health risk compared with infants of women who did not. METHODS: Participants were 135 mother-infant dyads drawn from a racially and ethnically diverse, low-income sample experiencing high stress. The women participated in an intervention trial during pregnancy that involved assignment to either mindfulness-based intervention or treatment-as-usual (TAU). Infants of women from both groups were assessed at 6 months of age on sympathetic (preejection period), parasympathetic (respiratory sinus arrhythmia), and observed behavioral (negativity and object engagement) reactivity and regulation during the still face paradigm. Linear mixed-effects and generalized linear mixed-effects models were used to examine treatment group differences in infant outcomes. RESULTS: Relative to those in the intervention group, infants in the TAU group showed a delay in sympathetic activation and subsequent recovery across the still face paradigm. In addition, infants in the intervention group engaged in higher proportions of self-regulatory behavior during the paradigm, compared with the TAU group. No significant effect of intervention was found for parasympathetic response or for behavioral negativity during the still face paradigm. CONCLUSIONS: Findings provide evidence that maternal participation in a short-term, group mindfulness-based intervention during pregnancy is associated with the early development of salutary profiles of biobehavioral reactivity and regulation in their infants. Because these systems are relevant for psychopathology and physical health, prenatal behavioral interventions may benefit two generations.

Respiratory Sinus Arrhythmia Change during Trauma-Focused Cognitive-Behavioral Therapy: Results from a Randomized Controlled Feasibility Trial.

Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT) is a well-established treatment for pediatric posttraumatic stress disorder (PTSD). Animal-assisted therapy (AAT) has been proposed as an adjunct to TF-CBT that may improve treatment effects through enhanced targeting of affect regulation, as indexed by specific changes in the respiratory sinus arrhythmia (RSA). The current study reports results from a randomized controlled feasibility trial (N = 33; Mage = 11.79 [SD = 3.08]; 64% White; 67% female) that measured RSA during Sessions 1, 4, 8, and 12 of a twelve-session TF-CBT protocol and tested whether: 1) TF-CBT + AAT achieved higher average RSA amplitudes relative to TF-CBT alone, and 2) RSA regulation, defined as less variability around person-specific RSA slopes during treatment, explained variation in post-treatment PTSD symptoms. Multilevel modeling failed to support an effect for TF-CBT + AAT on RSA amplitudes (δ001 = 0.08, p = 0.844). However, regardless of treatment condition, greater RSA withdrawal was observed within Sessions 4 (γ11 = -.01, p < .001) and 12 (γ13 = -.01, p = .015) relative to the Session 1 baseline. The average level of RSA amplitude in Session 8 was also significantly lower compared to Session 1 (γ02 = -0.70, p = .046). Intraindividual regression models demonstrated that greater RSA regulation predicted improved PTSD symptoms at post-treatment after adjusting for pre-treatment levels (b3 = 20.00, p = .012). These preliminary results offer support for future confirmatory trials testing whether affect regulation, as indexed by changes in RSA, is a mechanism of action for TF-CBT in the treatment of pediatric PTSD.

The Current Evidence Levels for Biofeedback and Neurofeedback Interventions in Treating Depression: A Narrative Review.

This article is aimed at showing the current level of evidence for the usage of biofeedback and neurofeedback to treat depression along with a detailed review of the studies in the field and a discussion of rationale for utilizing each protocol. La Vaque et al. criteria endorsed by the Association for Applied Psychophysiology and Biofeedback and International Society for Neuroregulation & Research were accepted as a means of study evaluation. Heart rate variability (HRV) biofeedback was found to be moderately supportable as a treatment of MDD while outcome measure was a subjective questionnaire like Beck Depression Inventory (level 3/5, "probably efficacious"). Electroencephalographic (EEG) neurofeedback protocols, namely, alpha-theta, alpha, and sensorimotor rhythm upregulation, all qualify for level 2/5, "possibly efficacious." Frontal alpha asymmetry protocol also received limited evidence of effect in depression (level 2/5, "possibly efficacious"). Finally, the two most influential real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback protocols targeting the amygdala and the frontal cortices both demonstrate some effectiveness, though lack replications (level 2/5, "possibly efficacious"). Thus, neurofeedback specifically targeting depression is moderately supported by existing studies (all fit level 2/5, "possibly efficacious"). The greatest complication preventing certain protocols from reaching higher evidence levels is a relatively high number of uncontrolled studies and an absence of accurate replications arising from the heterogeneity in protocol details, course lengths, measures of improvement, control conditions, and sample characteristics.

The autonomic nervous system in its natural environment: Immersion in nature is associated with changes in heart rate and heart rate variability.

Stress Recovery Theory (SRT) suggests that time spent in nature reduces stress. While many studies have examined changes in stress physiology after exposure to nature imagery, nature virtual reality, or nature walks, this study is the first to examine changes in heart rate (HR) and vagally mediated HR variability, as assessed by Respiratory Sinus Arrythmia (RSA), after a longer duration of nature exposure. Consistent with SRT, we hypothesized that immersion in nature would promote stress recovery, as indexed by an increase in RSA and a decrease in HR. We also predicted that exposure to nature would improve self-reported mood. We used a within-subjects design (N = 67) to assess changes in peripheral physiology before, during, and after a 5-day nature trip. Results demonstrated a significant decrease in RSA and a significant increase in HR during the trip compared to before or after the trip, suggesting that immersion in nature is associated with a shift toward parasympathetic withdrawal and possible sympathetic activation. These results were contrary to our hypotheses and may suggest increased attentional intake or presence of emotions associated with an increase in sympathetic activation. We also found an improvement in self-reported measures of mood during the trip compared to before or after the trip, confirming our hypotheses and replicating previous research. Implications of this study are discussed in the context of SRT.

Psychophysiological responses to various slow, deep breathing techniques.

Deep breathing exercises are commonly used for several health conditions including pain and hypertension. Various techniques are available to practice deep breathing, whereas possible differential psychophysiological effects have not been investigated. We compared four deep breathing techniques and examined outcomes in blood pressure variability, respiratory sinus arrhythmia, baroreflex function, and emotional state. Healthy adult volunteers performed pursed-lips breathing, left and right unilateral nostril breathing, and deep breathing with an inspiratory threshold load (loaded breathing), all at a frequency of 0.1 Hz (i.e., controlled breathing) and for three minutes each. Results showed that blood pressure variability was higher during loaded breathing versus other conditions and higher during pursed-lips breathing versus left and right unilateral nostril breathing. Respiratory sinus arrhythmia was higher during loaded breathing versus other conditions and higher during pursed-lips breathing versus left unilateral nostril breathing. The effect of breathing condition on respiratory sinus arrhythmia was mediated by alterations in blood pressure variability. There was no difference between the breathing conditions in baroreflex sensitivity or effectiveness. Participants rated pursed-lips breathing as more calming and pleasant and with more sense of control (vs. other conditions). Overall, among the four tested deep breathing techniques, loaded breathing was associated with enhanced cardiovascular effects and pursed-lips breathing with better emotional responses, while also enhancing cardiovascular effects (albeit less than loaded breathing). These findings can be informative in applying deep breathing techniques as self-management interventions for health conditions, in which baroreceptors stimulation and autonomic and emotional modulations can be beneficial, such as pain and hypertension.

Development and Pilot Test of a Virtual Reality Respiratory Biofeedback Approach.

Breathing exercises with biofeedback have benefits over breathing exercises without biofeedback. However, the traditional measurement of respiratory signals that is required as part of feeding back the breath incurs high cost and effort. We propose a novel virtual reality (VR) based approach to respiratory biofeedback that utilizes the positionally tracked hand controllers integrated into modern VR systems to capture and feedback the respiration-induced abdominal movements. In a randomized controlled laboratory study, we investigated the feasibility and efficacy of the developed biofeedback algorithm. In total, 72 participants performed a short breathing exercise in VR with or without respiratory biofeedback. The feedback integration resulted in a satisfactory user experience, a heightened breath awareness, a greater focus on slow diaphragmatic breathing and an increased respiratory sinus arrhythmia. This evidences that the novel biofeedback approach is low-cost, unobtrusive, usable and effective in increasing breath awareness and promoting slow diaphragmatic breathing in the context of VR-based breathing exercises. Future studies need to investigate the broader applicability and long-term effects.

Getting Specific about Emotion and Self-Inflicted Injury: An Examination Across Emotion Processes in Borderline Personality Disorder.

This study aimed to examine which specific emotion processes influence self-inflicted injury: basal respiratory sinus arrhythmia, baseline negative emotional intensity, emotional reactivity, or emotion regulation deficits. Self-injuring individuals with borderline personality disorder (N = 22) reported their lifetime self-injury frequency. Basal respiratory sinus arrhythmia and baseline skin conductance responses measurements were collected. Participants then either reacted as they usually would (i.e., emotional reactivity), or utilized mindfulness- or distraction-based strategies (i.e., emotion regulation), in response to negative images while self-reported negative emotion and skin conductance were monitored. Higher basal respiratory sinus arrhythmia and baseline emotional intensity predicted higher lifetime self-injury frequency. Chronic, resting emotion processes may be more important targets for reducing self-injury compared to labile, acute emotion processes.

Use your words: The role of emotion labeling in regulating emotion in borderline personality disorder.

Borderline personality disorder (BPD) treatments emphasize emotion labeling to decrease negative emotion and facilitate emotion regulation. However, no studies have examined emotion labeling in BPD or its impact on intentional emotion regulation. The present study examined the impact of emotion labeling on emotion and intentional emotion regulation attempts across self-reported and physiological indices (i.e., skin conductance response [SCR], respiratory sinus arrhythmia [RSA]) in BPD and healthy control (HC) groups. Participants listened to emotionally-evocative scripts and were either instructed to type the emotions that they were experiencing (labeling) or the objects they could imagine seeing in the script (control) into a computer. Following this, they were instructed to use either mindfulness or cognitive reappraisal to decrease their emotion. Self-reported, RSA, and SCR indices of negative emotion were collected throughout and analyzed using generalized estimating equations. Findings indicated that the BPD group experienced higher RSA during emotion labeling compared to the control task, but the HC group did not. HCs reported lower negative emotion after emotion labeling when implementing both emotion regulation strategies compared to the control task, but the BPD group did not. These findings suggest that emotion labeling may activate emotion regulatory systems in BPD and can potentiate intentional emotion regulation in HCs.

Influence of inspiratory threshold load on cardiovascular responses to controlled breathing at 0.1 Hz.

Slow, deep breathing is being used as a self-management intervention for various health conditions including pain and hypertension. Stimulation of the arterial baroreceptors and increased vagal modulation are among the proposed mechanisms for the therapeutic effects of slow, deep breathing. We investigated whether adding inspiratory threshold load can enhance the cardiovascular responses to controlled breathing at the frequency of 0.1 Hz, a common form of slow, deep breathing. Healthy volunteers (N = 29) performed controlled breathing at 0.1 Hz (6 breaths/minute) without load and with inspiratory threshold loads of 5 cmH2 O and 10 cmH2 O. Respiratory airflow, heart rate, and blood pressure were continuously recorded. The amplitude of the systolic blood pressure variation during respiratory cycles increased with increasing loads. Respiratory sinus arrhythmia was higher during controlled breathing at 0.1 Hz with the load of 10 cmH2 O compared to without load. Baroreflex sensitivity was not affected by loads. The effect of loads on respiratory sinus arrhythmia was mediated by increasing the amplitude of systolic blood pressure variation during respiratory cycles. These results suggest that applying small inspiratory threshold loads during controlled breathing at 0.1 Hz increases cardiac vagal modulation by this breathing exercise. This effect seems to be mediated by stronger stimulation of the arterial baroreceptors because of larger systolic blood pressure swings along the respiratory cycle. The potential benefit of long-term practice of controlled breathing at 0.1 Hz with inspiratory threshold loads on baroreflex function and cardiac vagal control needs to be investigated, particularly in pain and hypertension patients.

Protective effect of heart rate variability biofeedback on stress-induced lung function impairment in asthma.

Psychological stress can provoke airway constriction in asthmatic patients, which may be because of autonomic nervous system dysfunction in asthma. We investigated the effect of enhancing respiratory sinus arrhythmia using heart rate variability biofeedback (HRV-BF) on spirometry performance and HRV indices during stress induced by Stroop Color-Word interference test in asthmatic patients and healthy volunteers. Stress caused decrease in FEV1%, FVC%, and PEF% compared to baseline in asthmatic patients, but not in healthy subjects. A single short duration episode of HRV-BF not only had a protective effect on stress-induced airway constriction, but also significantly augmented the level of FEV1% and FVC% as compared with their own baseline. Also, there was a significant correlation between HRV changes and the augmentation of spirometry performance in asthmatic patients receiving HRV-BF. Our findings indicated that even a single short duration episode of HRV-BF can decrease susceptibility to stress-induced lung function impairment in patients with asthma, which may be through the modulation of respiratory sinus arrhythmia.

Psychological and Autonomic Correlates of Emotion Dysregulation among Women in Substance Use Disorder Treatment.

BACKGROUND: Emotion regulation is increasingly recognized as important for the prevention and treatment of substance use disorder (SUD). However, there is an identified lack of physiological indexes of emotion dysregulation in SUD treatment studies, critically needed to better understand the link between emotion regulation capacity (measured physiologically) and self-report health outcomes among individuals in SUD treatment. OBJECTIVE: To examine the association between respiratory sinus arrhythmia (RSA) and self-report health outcomes among women in SUD treatment. METHODS: This is a cross-sectional study based on baseline data from 217 women enrolled in a randomized control trial to study a mind-body intervention as an adjunct to SUD treatment. All participants were enrolled in community-based outpatient treatment. Participants were administered questionnaires to examine sample characteristics, mental health symptoms, and interoceptive awareness and mindfulness skills. RSA data was gathered as an index of emotion dysregulation. Descriptive statistics, bivariate correlations, and regression were used in the analyses. RESULTS: Findings highlight the extensive trauma histories, low SES, and the high symptoms of distress in this sample. RSA was only significantly correlated with interoceptive awareness after controlling for age and BMI. Measures of symptomatic distress and mindfulness were not correlated with RSA. Conclusions/Importance: Results provide the first evidence of RSA as an index of interoceptive awareness in this population. The inclusion of biomarkers such as RSA in SUD clinical studies may help identify individuals that are in need of targeted treatments that include interoceptive awareness training focused on improving emotion regulation.

Anxiety, depressive symptoms, and cardiac autonomic function in perimenopausal and postmenopausal women with hot flashes: a brief report.

OBJECTIVE: The aim of the study was to examine whether anxiety and depressive symptoms are associated with an adverse cardiac autonomic profile among midlife women with hot flashes. METHODS: Anxiety and depressive symptoms were evaluated by validated self-administered questionnaires among peri- and postmenopausal women in a randomized trial of slow-paced respiration for hot flashes. Pre-ejection period (PEP), a marker of sympathetic activation, and respiratory sinus arrhythmia (RSA), a marker of parasympathetic activation, were measured at baseline and 12 weeks using impedance cardiography and electocardiography. Multivariable repeated measures linear regression models examined associations between anxiety and depression symptoms and autonomic markers, corrected for multiple comparisons with Benjamini-Hochberg procedure, and adjusted for age and body mass index. RESULTS: Among the 121 participants, greater state anxiety was associated with shorter PEP, reflecting higher sympathetic activity (ß = -0.24, P = 0.02). Greater trait anxiety and cognitive anxiety were associated with lower RSA, reflecting decreased parasympathetic activity (ß = -0.03, P < 0.01 for Spielberger Trait Anxiety; ß = -0.06, P = 0.02 for Hospital Anxiety and Depression Scale [HADS] Anxiety Subscale). Greater depressive symptoms were associated with lower RSA (ß = -0.06, P = 0.03 for HADS Depression Subscale; ß = -0.03, P = 0.04 for Beck Depression Inventory). CONCLUSIONS: Among peri- and postmenopausal women with hot flashes, greater self-reported anxiety and depressive symptoms were associated with lower levels of resting cardiac parasympathetic activity, and greater state anxiety was associated with higher levels of cardiac sympathetic activity. Findings suggest that midlife women with increased anxiety and depressive symptoms may have an unfavorable cardiac autonomic profile with potential implications for their overall cardiovascular risk.

Brief mindfulness training de-couples the anxiogenic effects of distress intolerance on reactivity to and recovery from stress among deprived smokers.

OBJECTIVE: We tested whether mindfulness de-couples the expected anxiogenic effects of distress intolerance on psychological and physiological reactivity to and recovery from an anxiogenic stressor among participants experimentally sensitized to experience distress. METHOD: N = 104 daily smokers underwent 18-hours of biochemically-verified smoking deprivation. Participants were then randomized to a 7-min analogue mindfulness intervention (present moment attention and awareness training; PMAA) or a cope-as-usual control condition; and subsequently exposed to a 2.5-min paced over breathing (hyperventilation) stressor designed to elicit acute anxious arousal. Psychological and physiological indices of anxious arousal (Skin Conductance Levels; SCL) as well as emotion (dys)regulation (Respiratory Sinus Arrhythmia; RSA) were measured before, during and following the stressor. RESULTS: We found that PMAA reduced psycho-physiological dysregulation in response to an anxiogenic stressor, as well as moderated the anxiogenic effect of distress intolerance on psychological but not physiological responding to the stressor among smokers pre-disposed to experience distress via deprivation. CONCLUSIONS: The present study findings have a number of theoretical and clinical implications for work on mindfulness mechanisms, distress tolerance, emotion regulation, and smoking cessation interventions.

The effect of verbal and imagery-based worry versus distraction on the emotional response to a stressful in-vivo situation.

BACKGROUND AND OBJECTIVES: According to the Contrast Avoidance Model of worry, worrying induces prolonged negative affect and arousal and thereby suppresses sharp shifts in negative affect. The verbal and abstract nature of worry may be responsible for these effects as verbal thinking has been found to lead to less emotional and physiological responding than imagery. The present study was designed to test the Contrast Avoidance Model and to examine the role of verbal vs. imagery-based thinking during worrying.. METHODS: 125 participants were exposed to a social-evaluative stressor. Before the stressor, they were randomized into three different groups (1) verbal worrying about the upcoming stressor, (2) imagery-based worrying, or (3) distraction. Self-reported affect and physiological arousal, as well as heart rate, respiratory sinus arrhythmia and skin conductance level (SCL) were monitored. RESULTS: In line with the Contrast Avoidance Model, worrisome thinking (1) led to immediately increased self-reported negative affect and arousal as well as SCL, but (2) attenuated a further increase in self-reported negative affect and arousal in response to the stressor. No effect of style of worrying (verbal vs. imagery) was found.. LIMITATIONS: Effects were rather small and mostly confined to self-report data. CONCLUSION: By and large, our findings support the Contrast Avoidance Model of worry with regard to self-report measures and extend earlier findings by using an in-vivo stressor. The role of thinking style on the contrast avoidance effect as well as the contrast avoidance effect on physiological measures need to be explored in more detail..

Respiratory sinus arrhythmia as a potential measure in substance use treatment--outcome studies.

BACKGROUND AND AIMS: Dysfunction of physiological regulation systems may underlie the disrupted emotional and self-regulatory processes among people with substance use disorder (SUD). This paper reviews evidence as to whether or not respiratory sinus arrhythmia (RSA), as a psychophysiological index of emotional regulation, could provide useful information in treatment-outcome research to provide insights into recovery processes. METHODS: We reviewed the use of RSA in clinical research and studies on SUD treatment. Search terms for the review of RSA in clinical research included respiratory sinus arrhythmia, heart rate variability, vagal, cardiac vagal control, psychophysiology, intervention, treatment, mindfulness, mind-body, mental health, substance use, chemical dependence, regulation and emotion regulation. For the review of RSA in intervention studies, we included only those that provided adequate description of psychophysiological methods, and examined RSA in the context of an intervention study. RESULTS: RSA appears to be able to provide an index of self-regulatory capacity; however, it has been little used in either intervention or treatment research. Of the four intervention studies included in this review, all were mindfulness-based interventions. Two studies were with substance-using samples, and both showed pre-post increases in RSA and related improved substance use outcomes. Two of the three studies were randomized controlled trials (RCTs), and both showed significant increases in RSA in the experimental compared to comparison condition. CONCLUSION: Respiratory sinus arrhythmia may be a useful index of emotional regulation in people with substance use disorder, and a potential measure of underlying mechanisms for SUD treatment studies, particularly mindfulness-based interventions.

Improving Managers' Psychophysical Well-Being: Effectiveness of Respiratory Sinus Arrhythmia Biofeedback.

High work stress has been consistently associated with disturbed autonomic balance, specifically, lowered vagal cardiac control and increased sympathetic activity, which may lead to increased cardiovascular risk. Stress management procedures have been proposed to reduce autonomic dysfunctions related to work stress in different categories of workers exposed to heightened work demands, while a limited number of studies addressed this issue in managers. The present study was aimed at evaluating the effectiveness of a respiratory sinus arrhythmia (RSA) biofeedback (BF) intervention on psychological and physiological outcomes, in managers with high-level work responsibilities. Thirty-one managers leading outstanding private or public companies were randomly assigned to either a RSA-BF training (RSA-BF; N = 16) or a control group (N = 15). The RSA-BF training consisted of five weekly 45 min sessions, designed to increase RSA, whereas controls had to provide a daily stress diary once a week. After the training, managers in both groups reported reduced heart rate at rest, lower anxiety levels and improvement in health-related quality of life. More importantly, managers in the RSA-BF group showed increased vagal control (as indexed by increased RSA), decreased sympathetic arousal (as indexed by reduced skin conductance and systolic blood pressure) and lower emotional interferences, compared to managers in the control group. Results from this study showed that RSA-BF training was effective in improving cardiac autonomic balance at rest. Moreover, findings from this study underline the effectiveness of biofeedback in reducing psychophysiological negative outcomes associated with stress in managers.

Dissociation between the cognitive and interoceptive components of mindfulness in the treatment of chronic worry.

OBJETIVES: Despite the increasing interest in mindfulness, the basic components and action mechanisms of mindfulness remain controversial. The present study aims at testing the specific contribution of two components of mindfulness -attention to cognitive experience (metacognition) and awareness of interoceptive sensations (metainteroception)- in the treatment of chronic worry. METHOD: Forty five female university students with high scores in the Penn State Worry Questionnaire were split into three groups: a mindfulness cognitive training group, a mindfulness interoceptive training group, and a non-intervention control group. Participants were assessed before and after the intervention using physiological indices of autonomic regulation (skin conductance, heart rate, heart rate variability, and respiratory sinus arrhythmia) and self-report indices of mindfulness and clinical symptoms (chronic worry, depression, positive and negative affect, and perceived stress). RESULTS: Both mindfulness training groups showed significant improvement after the intervention in self-report indices of mindfulness and clinical symptoms. However, the interoceptive training group was superior in also showing significant improvement in the physiological indices of autonomic regulation. LIMITATIONS: The relatively small sample size may have increased the probabilities of type I and II errors. Our Intervention program was relatively short. The participants were all female. CONCLUSIONS: These results support the hypothesis that, in the context of treating chronic worry, the interoceptive and cognitive components can be somewhat dissociated and that, when both components are applied separately, compared to a non-intervention condition, the interoceptive component is more effective.

Inhalation/Exhalation ratio modulates the effect of slow breathing on heart rate variability and relaxation.

Slow breathing is widely applied to improve symptoms of hyperarousal, but it is unknown whether its beneficial effects relate to the reduction in respiration rate per se, or, to a lower inhalation/exhalation (i/e) ratio. The present study examined the effects of four ventilatory patterns on heart rate variability and self-reported dimensions of relaxation. Thirty participants were instructed to breathe at 6 or 12 breaths/min, and with an i/e ratio of 0.42 or 2.33. Participants reported increased relaxation, stress reduction, mindfulness and positive energy when breathing with the low compared to the high i/e ratio. A lower compared to a higher respiration rate was associated only with an increased score on positive energy. A low i/e ratio was also associated with more power in the high frequency component of heart rate variability, but only for the slow breathing pattern. Our results show that i/e ratio is an important modulator for the autonomic and subjective effects of instructed ventilatory patterns.

Optimum arousal level preservation system using biosignals.

The purpose of this study is to develop a driver's optimum arousal level preservation system while driving. The important point of developing this system is how we keep a driver's adequate conditions on driving. Most of the systems, which have been already put to practical use, are using audible sound or warning messages on a display to urge driver to take a rest. However, arousal levels are strongly related to the balance of autonomic modulations; therefore we need the stimulation that preserves a driver's adequate condition physiologically. Some preceding studies reported that the stimulation using the biological rhythms especially heart beating rhythms are influential to human body. We gave a consideration to this fact and made a course of using driver's heartbeat rhythm for the feedback stimulation to realize the demand. In this paper, we examined the stimulation from two points of views. The one is to investigate the possibilities of controlling a driver's heartbeat rhythms by making synchronization between the driver's heartbeat and a vibratory stimulation. The other one is to find out the stimulation that induces RSA (Respiratory Sinus Arrhythmia) in order to adjust the parasympathetic modulations. The result of the experiment indicated that the 1 [s] constant beat stimulation has an effect of inducing RSA, and the stimulation using a rhythm of heartbeat has a possibility of controlling driver's heart rate variability, and its' efficiency might be possible to be improved by adjusting the rhythm of the stimulation to the driver's heartbeat rhythms.