Illusions, arithmetic, and the bidirectional modulation of vagal control of the heart

Childhood maltreatment and substance use risk: A moderated mediation model of autonomic reactivity and distress tolerance

BACKGROUND/AIMS

The link between child maltreatment (CM) and substance use (SU) in young adulthood is established. The sympathetic nervous system (SNS) division of the autonomic nervous system may mediate this link. However, less is known on the indirect link between CM and SU via SNS functioning. Due to individual variability in the link between SNS functioning and SU risk, we aimed to examine the moderating role of distress tolerance (DT).

METHODS

A longitudinal sample of 118 young adults (YAs) from a low socioeconomic status background were assessed twice (between 9 and 12 months apart). CM, DT, and galvanic skin response (GSR) stress reactivity were measured during the initial study visit, while SU was assessed at both timepoints. Stress reactivity was assessed by measuring the GSR reactivity during a stress task. We tested the indirect associations between CM and changes in SU problems via GSR stress reactivity, and the moderation effects of DT on these indirect associations. A mediation model in the structural equation modeling (SEM) framework was then followed by a moderated mediation model to analyze these data.

RESULTS

YA's stress reactivity mediated the association between CM and alcohol use problems, and this indirect effect was weaker among YAs who had higher levels of DT. This pattern did not emerge with drug use problems.

CONCLUSIONS

Findings suggest that intervention and prevention efforts for SU outcomes should consider incorporating strategies that increase at-risk individuals' levels of DT. Providing strategies to help individuals stem their stress reactivity may reduce their risk for alcohol use.

Non-suicidal Self-injury History Moderates the Association Between Maternal Emotional Support and Adolescent Affect During Conflict

Onset of non-suicidal self-injury (NSSI) is most frequent during adolescence. Etiological models indicate that abnormal affective reactivity and regulation within interpersonal contexts is related to heightened NSSI risk. The current study examined the effects of maternal emotional support on adolescent sympathetic nervous system (SNS) activity and observed anger during a conflict discussion among 56 mother-daughter dyads consisting of healthy adolescents and adolescents with a history of self-injury. During the conflict discussion task, maternal emotional support and adolescent anger were coded from behavior, and cardiovascular pre-ejection period was used to index SNS responding. Results demonstrated that maternal emotional support was negatively associated with adolescent anger and SNS activity during the conflict. However, these associations were not significant among adolescents with heightened NSSI history. Maternal emotional support may serve as an interpersonal mechanism for adolescent physiological and behavioral regulation, yet may function differently among adolescents with more frequent NSSI.

Reactivity of observers' facial skin blood flow depending on others' facial expressions and blushing

Facial skin blood flow (SkBF) has attracted attention as an autonomic indicator because it influences facial colour, which informs others of emotional states, and facial temperature related to social anxiety. Previous studies have examined the facial SkBF in people experiencing emotions; however, facial SkBF changes in the observers of emotions are poorly understood. Our study clarified facial SkBF changes related to observing others' emotions by comparing the changes with other physiological indices. Thirty healthy participants (24 females; mean age: 22.17) observed six types of facial expressions (neutral, angry, and embarrassed expressions with and without facial blushing) and rated the emotional intensity of the other person. We measured their facial SkBF, finger SkBF, and cardiac RR interval as they made their observations. Facial SkBF generally decreased in relation to observing emotional faces (angry and embarrassed faces) and significantly decreased for angry expressions with blushing. None of the participants noticed blushing of facial stimuli. For the RR interval and finger SkBF, there was no variation depending on the observed facial expressions, although there was a general increase related to observation. These results indicated that facial SkBF is sensitive and reactive to emotional faces-especially angry faces with blushing- compared with other autonomic indices. The facial SkBF changes were not related to either RR interval changes or the intensity rating, suggesting that facial SkBF changes may be caused by vasoconstriction and have potential functions for our emotions. The decrease in facial SkBF may have a role in calming observers by preventing them from adopting the same emotional state as a person with intense anger. These findings clarify daily facial SkBF fluctuations and their relationship with our emotional processing in interpersonal situations.

Nonlinear neural patterns are revealed in high frequency functional near infrared spectroscopy analysis

Functional Near Infrared Spectroscopy (fNIRS) is a useful tool for measuring hemoglobin concentration. Linear theory of the hemodynamic response function supports low frequency analysis (<0.2 Hz). However, we hypothesized that nonlinearities, arising from the complex neurovascular interactions sustaining vasomotor tone, may be revealed in higher frequency components of fNIRS signals. To test this hypothesis, we simulated nonlinear hemodynamic models to explore how blood flow autoregulation changes may alter evoked neurovascular signals in high frequencies. Next, we analyzed experimental fNIRS data to compare neural representations between fast (0.2-0.6 Hz) and slow (<0.2 Hz) waves, demonstrating that only nonlinear representations quantified by sample entropy are distinct between these frequency bands. Finally, we performed group-level distance correlation analysis to show that the cortical distribution of activity is independent only in the nonlinear analysis of fast and slow waves. Our study highlights the importance of analyzing nonlinear higher frequency effects seen in fNIRS for a comprehensive analysis of cortical neurovascular activity. Furthermore, it motivates further exploration of the nonlinear dynamics driving regional blood flow and hemoglobin concentrations.

Slow yoga breathing improves mental load in working memory performance and cardiac activity among yoga practitioners

This study investigated the immediate effect of slow yoga breathing (SYB) at 6 breaths per minute (bpm) simultaneously on working memory performance and heart rate variability (HRV) in yoga practitioners. A total of 40 healthy male volunteers performed a working memory task, ‘n-back’, consisting of three levels of difficulty, 0-back, 1-back, and 2-back, separately, before and after three SYB sessions on different days. The SYB sessions included alternate nostril breathing (ANB), right nostril breathing (RNB), and breath awareness (BAW). Repeated measures analysis of variance showed a significant reduction in reaction time (ms) in 2-back condition immediately after ANB (−8%), RNB (−8%) and BAW (−5%) practices. Similarly, the accuracy was improved in the 0-back condition after RNB (4%), and in the 2-back condition after ANB (6%) and RNB (6%) practices. These results suggest that SYB practice enhances cognitive abilities (8–9%) related to memory load and improves the functioning of cardiac autonomic activity, which is required for the successful completion of mental tasks.Trial registered in the Clinical Trials Registry of India (CTRI/2018/01/011132).

Heart Rate Variability and Pain Sensitivity in Chronic Low Back Pain Patients Exposed to Passive Viewing of Photographs of Daily Activities

OBJECTIVE

Investigation if emotional reactivity by measuring heart rate variability (HRV) and pressure pain sensitivity during a passive visualization task in participants with chronic low back pain (CLBP).

MATERIALS AND METHODS

This case-control study was composed of 47 participants with CLBP and 47 asymptomatic participants. Both groups were submitted to a passive visualization task using 27 pictures from PHODA (Photograph Series of Daily Activities). HRV frequency domains were measured before, during, and after the task. Pressure pain threshold and pain intensity were also measured before and after the task.

RESULTS

The adjusted mean difference was statistically significant for HRV frequency domains during the visualization task, including low frequency [-5.92; 95% confidence interval (CI)=-9.60 to -2.23], high frequency (-0.71; 95% CI=-1.02 to -0.39), and low-frequency/high-frequency ratio (8.82; 95% CI=5.19 to 12.45). Pressure pain threshold decreased after the task in the CLBP group in all body sites, and pain intensity increased (-0.8; 95% CI=-1.16 to -0.39).

DISCUSSION

Aversive environmental stimuli, such as visual cues, may generate defensive physiological reactions. HRV can provide a measure that reflects the perceptions of threat and safety in the environment. Participants with CLBP presented changes in sympathovagal balance during passive visualization of pictures of daily activities, higher pain sensitivity, and high pain intensity when they were exposed to a passive visualization task using pictures of daily living that may arouse fears of harm.

Physiological Stress Response Reactivity Mediates the Link Between Emotional Abuse and Youth Internalizing Problems

Youth who are raised in emotionally abusive families are more likely to have poor mental health outcomes such as depression and anxiety. However, the mechanisms of this association are unclear. The present study utilized a longitudinal sample of low-SES youth (N = 101, M_ageT1 = 10.24) to examine stress response reactivity (i.e. vagal withdrawal, sympathetic activation, and hypothalamic-pituitary-adrenal [HPA] axis activation) as mediators between emotional abuse and prospective youth internalizing symptoms. Results indicated that blunted HPA reactivity to a laboratory social stress task mediated the association between emotional abuse and youth internalizing symptoms. Emotional abuse was also associated with blunted parasympathetic nervous system activity (i.e. less vagal withdrawal than average). In sum, emotional abuse is a potent risk factor for youth internalizing symptoms, and this link may be mediated via dysregulation in physiological stress response systems. Primary prevention of childhood emotional abuse and secondary prevention programs that target self-regulation skills may reduce rates of youth internalizing symptoms and disorders.

Photoplethysmographic Waveform and Pulse Rate Variability Analysis in Hyperbaric Environments

The main aim of this work is to identify alterations in the morphology of the pulse photoplethysmogram (PPG) signal, due to the exposure of the subjects to a hyperbaric environment. Additionally, their Pulse Rate Variability (PRV) is analysed to characterise the response of their Autonomic Nervous System (ANS). To do that, 28 volunteers are introduced into a hyperbaric chamber and five sequential stages with different atmospheric pressures from 1 atm to 5 atm are performed. In this work, nineteen morphological parameters of the PPG signal are analysed: the pulse amplitude; eight parameters related to pulse width; eight parameters related to pulse area; and the two two pulse slopes. Also, classical time and frequency parameters of PRV are computed. Notable widening of the pulses width is observed in the stages analysed. The PPG area increases with pressure, with no significant changes when the initial pressure is recovered. These changes in PPG waveform may be caused by an increase in the systemic vascular resistance as a consequence of of vasoconstriction in the extremities, suggesting a sympathetic activation. However, the PRV results show an augmented parasympathetic activity and a reduction in the parameters that characterise the sympathetic response. So, only a sympathetic activation is detected in the peripheral region, as reflected by PPG morphology. The information regarding the ANS and the cardiovascular response that can be extracted from the PPG signal, as well as its compatibility with wet conditions make this signal the most suitable for studying the physiological response in hyperbaric environments.

Child Abuse and Neglect, Callous-Unemotional Traits, and Substance Use Problems: the Moderating Role of Stress Response Reactivity

Young adults who experienced child abuse and neglect (CAN) are at significant risk for callous-unemotional traits and substance use problems. Research shows that compromised self-regulation may increase risk for these maladaptive outcomes. In the present cross-sectional study, we examined the moderating role of self-regulation, indexed by heart rate variability reactivity, in the indirect link between CAN and alcohol and other drug use problems via callous-unemotional traits. We utilized a sample of mostly female undergraduate students (N = 130, 81% Female; M _age  = 20.72). We hypothesized that (a) CAN and alcohol or other drug use problems would be associated indirectly via elevations in callous-unemotional traits, and (b) that this indirect association would be exacerbated by elevated heart rate variability reactivity. Results indicated that increased callous-unemotional traits underlain in the link between CAN and alcohol or other drug use problems. Further, this indirect link was exacerbated among youth with elevated heart rate variability reactivity. These findings have significant implications for prevention by demonstrating that physiological self-regulation is important to target in substance use prevention among collegiate samples.

Cardiac sympathetic activation and parasympathetic withdrawal during psychosocial stress exposure in 6-month-old infants

Infant autonomic reactivity to stress is a potential predictor of later life health complications, but research has not sufficiently examined sympathetic activity, controlled for effects of physical activity and respiration, or studied associations among autonomic adjustments, cardiac activity, and affect in infants. We studied 278 infants during the repeated Still-Face Paradigm, a standardized stressor, while monitoring cardiac activity (ECG) and respiratory pattern (respiratory inductance plethysmography). Video ratings of physical activity and affect were also performed. Respiratory sinus arrhythmia (RSA) and T-wave amplitude (TWA) served as noninvasive indicators of cardiac parasympathetic and sympathetic activity, respectively. Responses were compared between infants who completed two still-face exposures and those who terminated after one exposure due to visible distress. Findings, controlled for physical activity, showed robust reductions in respiration-adjusted RSA and TWA, with more tonic attenuation of TWA. Infants completing only one still-face trial showed more pronounced autonomic changes and less recovery from stress. They also showed elevated minute ventilation, suggesting hyperventilation. Both reductions in adjusted RSA and TWA contributed equally to heart rate changes and were associated with higher negative and lower positive affect. These associations were more robust in the group of distressed infants unable to complete both still-face trials. Thus, cardiac sympathetic activation and parasympathetic withdrawal are part of the infant stress response, beyond associated physical activity and respiration changes. Their association with cardiac chronotropy and affect increases as infants' distress level increases. This excess reactivity to social stress should be examined as a predictor of future cardiovascular disease.

An autonomic nervous system context of harsh parenting and youth aggression versus delinquency

Harsh parenting is a significant predictor of youth aggression and delinquency. However, not every child exposed to adverse parenting develops such problem behaviors. Recent developmental evolutionary models suggest that variability in stress response reactivity to parenting, reflected by autonomic nervous system (ANS) functioning, may affect the impact of adverse parenting on youth behavioral adjustment. The aim of the present study was to investigate whether the parasympathetic and sympathetic branches of the ANS moderate the association between parenting and aggressive and delinquent behaviors. The study sample included low-income, ethnically diverse preadolescents (M = 10.28 years old; N = 101) and their caregivers. Direct effects were found from basal RSA to delinquent behaviors. In addition, harsh parenting predicted increased youths' aggressive and delinquent behaviors in the context of high RSA withdrawal and increased youths' delinquent behaviors in the context of shortened basal PEP. Implications for prevention and intervention are discussed.

Photoplethysmographic Waveform in Hyperbaric Environment

The objective of this work is the identification of significant variations of morphological parameters of the photoplethysmographic (PPG) signal when the subjects are exposed to an increase in atmospheric pressure. To achieve this goal, the PPG signal of 26 subjects, exposed to a hyperbaric environment whose pressure increases up to 5 atm, has been recorded. From this record, segments of 4 minutes have been processed at 1 atm, 3 atm and 5 atm, both in the descending (D) and ascending (A) periods of the immersion. In total, four states (3D, 5, 3A and 1A) normalized to the basal state (1D) have been considered. In these segments, six morphological parameters of the PPG signal were studied. The width, the amplitude, the widths of the anacrotic and catacrotic phases, and the upward and downward slopes of each PPG pulse were extracted. The results showed significant increases in the three parameters related to the pulse width. This increase is significant in the four states analysed for the anacrotic phase width. Furthermore, a significant decrease in the amplitude and in both slopes (in the states 1A) was observed. These results show that the PPG width responds rapidly to the increase in pressure, indicating an activation of the sympathetic system, while amplitude and pulse slopes are decreased when the subjects are exposed to the hyperbaric environment for a considerable period of time.

Autonomic nervous system functioning in early childhood: Responses to cognitive and negatively valenced emotional challenges

Although autonomic nervous system (ANS) functioning is "context-dependent," few studies examined children's normative sympathetic and parasympathetic autonomic responses to distinct challenges in early childhood years. Examining children's ANS responsivity to distinct challenges is important for understanding normative autonomic responses toward everyday life stressors and identifying paradigms that effectively elicit a "stress response." We examined children's (N = 278) sympathetic (preejection period [PEP]) and parasympathetic (respiratory sinus arrhythmia [RSA]) responses to cognitive (i.e., problem-solving and cognitive control) and negatively valenced emotional (i.e., blocked goal and unfairness) challenges in preschool, kindergarten, and grade 1. Children, on average, demonstrated parasympathetic inhibition (RSA withdrawal) in response to all challenges but the magnitude of these responses depended on the task. Children showed sympathetic activation (PEP shortening) toward the problem-solving task at each assessment and there was no sample-level change in the magnitude of this response over time. Children showed greater sympathetic responsivity toward the cognitive control task over time, with evidence for a sympathetic activation response only in grade 1. Children experienced sympathetic inhibition (PEP lengthening) toward the unfairness tasks but did not experience significant sympathetic responsivity toward the blocked goal tasks. Parasympathetic responsivity to most challenges were modestly stable but there was no stability in sympathetic responsivity across time.

Photoplethysmographic Waveform Versus Heart Rate Variability to Identify Low-Stress States: Attention Test

Our long-term goal is the development of an automatic identifier of attentional states. In order to accomplish it, we should first be able to identify different states based on physiological signals. So, the first aim of this paper is to identify the most appropriate features to detect a subject's high performance state. For that, a database of electrocardiographic (ECG) and photoplethysmographic (PPG) signals is recorded in two unequivocally defined states (rest and attention task) from up to 50 subjects as a sample of the population. Time and frequency parameters of heart/pulse rate variability have been computed from the ECG/PPG signals, respectively. Additionally, the respiratory rate has been estimated from both signals and also six morphological parameters from PPG. In total, 26 features are obtained for each subject. They provide information about the autonomic nervous system and the physiological response of the subject to an attention demand task. Results show an increase of sympathetic activation when the subjects perform the attention test. The amplitude and width of the PPG pulse were more sensitive than the classical sympathetic markers ([Formula: see text] and [Formula: see text]) for identifying this attentional state. State classification accuracy reaches a mean of [Formula: see text], a maximum of [Formula: see text], and a minimum of 85%, in the 100 classifications made by only selecting four parameters extracted from the PPG signal (pulse amplitude, pulsewidth, pulse downward slope, and mean pulse rate). These results suggest that attentional states could be identified by PPG.

Parasympathetic and sympathetic activity are associated with individual differences in neural indices of selective attention in adults

Multiple theoretical frameworks posit that interactions between the autonomic nervous system and higher-order neural networks are crucial for cognitive and emotion regulation. However, few studies have directly examined the relationship between measures of autonomic physiology and brain activity during cognitive tasks, and fewer studies have examined both the parasympathetic and sympathetic autonomic branches when doing so. Here, 93 adults completed an ERP auditory selective attention task concurrently with measures of parasympathetic activity (high-frequency heart rate variability; HF-HRV) and sympathetic activity (preejection period; PEP). We focus on the well-studied N1 ERP component to test for associations with baseline values of HF-HRV and PEP. Individuals with higher resting HF-HRV and shorter resting PEP showed larger effects of selective attention on their ERPs. Follow-up regression models demonstrated that HF-HRV and PEP accounted for unique variance in selective attention effects on N1 mean amplitude. These results are consistent with the neurovisceral integration model, such that greater parasympathetic activity is a marker of increased selective attention, as well as other theoretical models that emphasize the role of heightened sympathetic activity in more efficient attention-related processing. The present findings highlight the importance of autonomic physiology in the study of individual differences in neurocognitive function and, given the foundational role of selective attention across cognitive domains, suggest that both parasympathetic and sympathetic activity may be key to understanding variability in brain function across a variety of cognitive tasks.

Contributions of Psychophysiology to Research on Adult Attachment: Review and Recommendations

Despite the increasing use of psychophysiological measures to investigate social and interpersonal phenomena, few studies of adult romantic attachment have taken advantage of this approach. In this article I argue for a biologically-specific, theory-based integration of psychophysiological measures into adult attachment research. This approach would help elucidate the normative psychobiological properties of the attachment system, which have received little study in humans. Specifically, it would allow researchers to test targeted hypotheses regarding affect and arousal regulation in attachment relationships. I provide a general introduction to 2 biological systems that hold particular promise for adult attachment research: the parasympathetic branch of the autonomic nervous system and the hypothalamic-pituitary-adrenocortical axis of the endocrine system. I highlight the relevance of these systems for attachment phenomena and review findings from selected social psychophysiological research. I conclude by outlining a tentative theoretical model of the psychobiology of adult attachment and identifying specific directions for future research.

The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses

Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect can add to the explanation of prolonged stress-related CV responses that influence CV health.

Persisting Effects of Concussion on Heart Rate Variability during Physical Exertion

The purpose of this study was to evaluate cardiac autonomic modulation in university athletes during the post-acute to late phase (mean, 95 days ±63) of injury at rest and during physical exertion. We also sought to evaluate the effect of time since injury and number of injuries on heart rate variability (HRV). We hypothesized that physical exertion would reveal persisting modifications in HRV following a concussion. We included, in a cross-sectional design, athletes who sustained a concussion and matched controls. Concussions were identified by a medical doctor using established criteria. Twelve male concussed and 12 control athletes took part in the study. Control participants were teammates who were chosen to match the concussed athletes with regard to their height, weight, education, and age. The beat-to-beat electrocardiogram intervals of the participants were measured at rest and during physical exertion (isometric hand grip contraction; IHGC), which was sustained for 3 minutes at 30% of the participants' maximum. Linear and nonlinear parameters of HRV were calculated. The ratio between low and high frequency (LF/HF) bands was calculated to assess the sympathovagal balance. During the IHGC, but not at rest, concussed athletes presented significantly lower power in HF bands, leading to a significantly higher LF/HF ratio (p ≤ 0.05). Thus, asymptomatic athletes still may exhibit modifications in cardiac autonomic modulation weeks to months following injury. These modifications may only become apparent during physical exertion. Monitoring HRV may aid diagnosis and provide insight about safe return to play.

Multi-time scale perspective in analyzing cardiovascular data

Cardiovascular dynamic and variability data are commonly used in experimental protocols involving cognitive challenge. Usually, the analysis is based on a sometimes more and sometimes less well motivated single specific time resolution ranging from a few seconds to several minutes. The present paper aimed at investigating in detail the impact of different time resolutions of the cardiovascular data on the interpretation of effects. We compared three template tasks involving varying types of challenge, in order to provide a case study of specific effects and combinations of effects over different time frames and using different time resolutions. Averaged values of hemodynamic variables across an entire protocol confirmed typical findings regarding the effects of mental challenge and social observation. However, the hemodynamic response also incorporates transient variations in variables reflecting important features of the control system response. The fine-grained analysis of the transient behavior of hemodynamic variables demonstrates that information that is important for interpreting effects may be lost when only average values over the entire protocol are used as a representative of the system response. The study provides useful indications of how cardiovascular measures may be fruitfully used in experiments involving cognitive demands, allowing inferences on the physiological processes underlying the responses.

Family conflict, autonomic nervous system functioning, and child adaptation: state of the science and future directions

The family is one of the primary contexts of child development. Marital and parent-child conflict (family conflict) are common and predict a wide range of negative behavioral and emotional outcomes in children. Thus, an important task for developmental researchers is to identify the processes through which family conflict contributes to children's psychological maladjustment, as well as vulnerability and protective factors in the context of family conflict. In the current paper, we aim to advance a conceptual model that focuses on indices of children's autonomic nervous system (ANS) functioning that increase vulnerability or provide protection against psychological maladjustment in the context of family conflict. In doing so, we provide a selective review that reflects the state of the science linking family conflict, children's ANS activity, and child psychological adjustment, and offer directions and guidance for future research. Our hope is to accelerate research at the intersection of family conflict and ANS functioning to advance understanding of risk and resilience among children.

Macaque cardiac physiology is sensitive to the valence of passively viewed sensory stimuli

Autonomic nervous system activity is an important component of affective experience. We demonstrate in the rhesus monkey that both the sympathetic and parasympathetic branches of the autonomic nervous system respond differentially to the affective valence of passively viewed video stimuli. We recorded cardiac impedance and an electrocardiogram while adult macaques watched a series of 300 30-second videos that varied in their affective content. We found that sympathetic activity (as measured by cardiac pre-ejection period) increased and parasympathetic activity (as measured by respiratory sinus arrhythmia) decreased as video content changes from positive to negative. These findings parallel the relationship between autonomic nervous system responsivity and valence of stimuli in humans. Given the relationship between human cardiac physiology and affective processing, these findings suggest that macaque cardiac physiology may be an index of affect in nonverbal animals.

Associations of coping and appraisal styles with emotion regulation during preadolescence

We investigated the associations of appraisal and coping styles with emotion regulation in a community sample of preadolescents (N=196, 9-12 years of age), with appraisal, coping styles, and emotion regulation measured at a single time point. In a previous study, we identified five frustration and four anxiety emotion regulation profiles based on children's physiological, behavioral, and self-reported reactions to emotion-eliciting tasks. In this study, preadolescents' self-reported appraisal and coping styles were associated with those emotion regulation profiles. Overall, findings revealed that children who were more effective at regulating their emotions during the emotion-eliciting tasks had higher levels of positive appraisal and active coping when dealing with their own problems. Conversely, children who regulated their emotions less effectively had higher levels of threat appraisal and avoidant coping.

Differentiating challenge reactivity from psychomotor activity in studies of children's psychophysiology: considerations for theory and measurement

Current methods of assessing children's physiological "stress reactivity" may be confounded by psychomotor activity, biasing estimates of the relation between reactivity and health. We examined the joint and independent contributions of psychomotor activity and challenge reactivity during a protocol for 5- and 6-year-old children (N = 338). Measures of parasympathetic reactivity (respiratory sinus arrhythmia [RSA]) and sympathetic reactivity (preejection period [PEP]) were calculated for social, cognitive, sensory, and emotional challenge tasks. Reactivity was calculated relative to both resting and a paired comparison task that accounted for psychomotor activity effects during each challenge. Results indicated that comparison tasks themselves elicited RSA and PEP responses, and reactivity adjusted for psychomotor activity was incongruent with reactivity calculated using rest. Findings demonstrate the importance of accounting for confounding psychomotor activity effects on physiological reactivity.

Cardiac vagal control in nonmedicated depressed women and nondepressed controls: impact of depression status, lifetime trauma history, and respiratory factors

OBJECTIVE

To evaluate the impact of acute stress and relationship-focused imagery on cardiac vagal control, as indicated by levels of respiratory sinus arrhythmia (RSA), in depressed and nondepressed women. Impairment in cardiac parasympathetic (vagal) control may confer risk for cardiac mortality in depressed populations.

METHODS

Electrocardiogram and respiratory rate were evaluated in 15 nonmedicated depressed women and 15 matched controls during two laboratory conditions: 1) a relationship-focused imagery designed to elicit vagal activation; and 2) a speech stressor designed to evoke vagal withdrawal.

RESULTS

As expected, the relationship-focused imagery increased RSA (F(3,66) = 3.79, p = .02) and the speech stressor decreased RSA (F(3,66) = 4.36, p = .02) across women. Depressed women exhibited lower RSA during the relationship-focused imagery, and this effect remained after control for respiratory rate and trauma history (F(1,21) = 5.65, p = .027). Depressed women with a trauma history exhibited the lowest RSA during the stress condition (F(1,22) = 9.61, p = .05). However, after controlling for respiratory rate, Trauma History × Task Order (p = .02) but not Trauma History × Depression Group (p = .12) accounted for RSA variation during the stress condition.

CONCLUSION

Depression in women is associated with lower RSA, particularly when women reflect on a close love relationship, a context expected to elicit vagal activation and hence increase RSA. In contrast, depression-related variation in stressor-evoked vagal activity seems to covary with women's trauma history. Associations between vagal activity and depression are complex and should be considered in view of the experimental conditions under which vagal control is assessed, as well as physiological and behavioral factors that may affect vagal function.

Developmental trajectories of respiratory sinus arrhythmia and preejection period in middle childhood

Autonomic nervous system (ANS) activity has been linked repeatedly to children's socioemotional and behavioral adaptive functioning and development, yet the literature on how various indexes of ANS activity develop in childhood is sparse. We utilized latent growth modeling to investigate the development of respiratory sinus arrhythmia (RSA), an established index of parasympathetic nervous system (PNS), and preejection period (PEP), a marker of sympathetic nervous system (SNS) influence on the heart, in children aged 8-10 years. At age 8, 251 children (128 girls, 123 boys; 162 European American, 89 African American) participated. Longitudinal data were collected during two additional waves when children were 9 and 10 years of age, with a 1-year lag between each wave. Children's RSA and PEP exhibited significant stability over time. Marginally significant variability was found among children in how RSA changed over time (slope), but there was no significant interindividual variability in PEP changes over development. A conditional growth curve model (i.e., one with predictor variables) showed that initial levels of RSA and PEP and the slope of RSA over time were predicted by several demographic factors including the child's sex and race; RSA of European American children showed significant increases over time while African American children had higher initial RSA but no significant change over time. Findings extend basic knowledge in developmental biopsychology and have implications for research focusing on ANS measures as important predictors, moderators, and mediators of childhood adaptation.

Emotion regulation profiles, temperament, and adjustment problems in preadolescents

The longitudinal relations of emotion regulation profiles to temperament and adjustment in a community sample of preadolescents (N=196, 8-11 years at Time 1) were investigated using person-oriented latent profile analysis (LPA). Temperament, emotion regulation, and adjustment were measured at 3 different time points, with each time point occurring 1 year apart. LPA identified 5 frustration and 4 anxiety regulation profiles based on children's physiological, behavioral, and self-reported reactions to emotion-eliciting tasks. The relation of effortful control to conduct problems was mediated by frustration regulation profiles, as was the relation of effortful control to depression. Anxiety regulation profiles did not mediate relations between temperament and adjustment.

Individual Differences in Vagal Regulation Moderate Associations Between Daily Affect and Daily Couple Interactions

Previous research suggests that cardiac vagal regulation (indexed by respiratory sinus arrhythmia, or RSA) provides a physiological substrate for affect regulation, which presumably underlies adaptive interpersonal functioning.The authors tested these associations in the context of daily interactions between 68 cohabiting couples. Participants underwent a laboratory assessment of RSA during rest and also during a series of psychological stressors. Subsequently, they kept daily measures of affect and interaction quality for 21 days. Individual differences in baseline and stress levels of RSA moderated within-person associations between daily affect and the quality of couple interactions. The pattern of results differed for women versus men. Men with lower vagal tone or higher vagal reactivity had stronger associations between daily negative affect and daily negative interactions, and men with higher vagal tone had more positive daily interactions overall. Women with higher vagal tone had stronger associations between daily positive affect and daily positive interactions.

Phase synchronization of hemodynamic variables and respiration during mental challenge

We studied the synchronization of heart rate, blood pressure and respiration in the sympathetic and parasympathetic branches of the autonomic nervous system during a cancellation test of attention and during mental arithmetic tasks. The synchronization was quantified by the index γ, which has been adopted from the analysis of weakly coupled chaotic oscillators. We analyzed in twenty healthy women the continuous signals partitioned in low (LF, 0.04-0.15 Hz) and high (HF, 0.15-0.40 Hz) frequencies to investigate whether or not respiration is a main determinant of cardiovascular synchronization. We used surrogate data analysis to distinguish between causal relationships from those that occur by chance. The LF-components of R-R interval and blood pressure showed no synchronization with respiration, whereas synchronization between blood pressure and R-R interval exceeded that occurring by chance (p < .001). Although heart rate, blood pressure and respiratory frequency increased from rest to mental challenge, no effect of mental challenge on the synchronization of the LF-components was seen. The HF-components showed significant synchronization for all variables (p < .001). During mental challenge, synchronization between respiration and R-R interval, respiration and systolic blood pressure (SBP), as well as R-R interval and SBP decreased (p < .01), whereas under resting conditions, respiration was one of the dominant mechanisms determining heart rate variability and systolic blood pressure fluctuations. We conclude that the observed decrease of synchronization during mental challenge is not only driven by the increase in respiratory frequency but that 'top down' intervention by the control system at higher levels may play an additional role.

Low-level Pb and cardiovascular responses to acute stress in children: the role of cardiac autonomic regulation

OBJECTIVE

A number of studies suggest that Pb exposure increases cardiovascular disease risk in humans. As a potential mechanism for this effect, we recently reported a significant association between early childhood Pb levels and cardiovascular response to acute stress. The current study considers the association between current Pb levels and the autonomic nervous system activation pattern underlying the cardiovascular response to stress in a new cohort of children.

METHODS

We assessed blood Pb levels as well as cardiovascular responses to acute stress in 9-11 year old children (N=140). Sympathetic activation (measured with pre-ejection period) and parasympathetic activation (measured with high frequency heart rate variability) were also assessed.

RESULTS

In a sample with very low levels of blood Pb (M=1.0 μg/dL), we found that increasing blood Pb was associated with coinhibition of sympathetic and parasympathetic activation in response to acute stress. In addition, increasing Pb levels were associated with the hemodynamic stress response pattern typical of coinhibition--significantly greater vascular resistance and reduced stroke volume and cardiac output.

CONCLUSIONS

Blood Pb levels were associated with significant autonomic and cardiovascular dysregulation in response to acute psychological stress in children. Moreover, these effects were significant at Pb levels considered to be very low and notably well below the 10 μg/dL, the Centers for Disease Control and Prevention definition of an elevated blood Pb level. The potential for autonomic dysregulation at levels of Pb typical for many US children would suggest potentially broad public health ramifications.

Effects of Stimuli on Cardiovascular Reactivity Occurring at Regular Intervals During Mental Stress

Studies examining the direct effects of stimuli needed to perform mental stress tasks such as instructor commands at regular intervals during the mental task are limited to date. Because of the comprehensive effects of different stimuli, we studied the effect of short instructor commands occurring at regular intervals on the behavior of the cardiovascular system during two different types of tasks. Continuous beat-to-beat heart rate and blood pressure, respiration, thoracic impedance, skin conductance, and peripheral temperature were measured in 20 healthy females during a cancellation test of attention (stimuli interval of 20 s) and during mental arithmetic tasks (stimuli interval of 120 s). The transient effects of the stimuli on measures in the time domain as well as the effects of stimulus intervals on measures in the frequency domain (using spectral analysis) were examined. Instructor commands caused increases in several cardiovascular variables and in skin conductance. SBP (systolic blood pressure) and DBP (diastolic blood pressure) showed a significant stimulus response only during the mental arithmetic tasks. An effect of instructor commands at regular intervals was seen in the spectral analysis at 0.05 Hz (cancellation test of attention) and 1/120 Hz (mental arithmetic), according to the stimulus intervals of 20 s and 120 s used in these tasks. The findings suggest that even simple instructor commands given during high mental task load had a strong impact and can considerably influence measures of cardiovascular reactivity. The effects of paced stimuli should be considered when interpreting cardiovascular responses to task conditions with constant stimulus intervals.

Effects of mental stress on autonomic cardiac modulation during weightlessness

Sustained weightlessness affects all body functions, among these also cardiac autonomic control mechanisms. How this may influence neural response to central stimulation by a mental arithmetic task remains an open question. The hypothesis was tested that microgravity alters cardiovascular neural response to standardized cognitive load stimuli. Beat-to-beat heart rate, brachial blood pressure, and respiratory frequency were collected in five astronauts, taking part in three different short-duration (10 to 11 days) space missions to the International Space Station. Data recording was performed in supine position 1 mo before launch; at days 5 or 8 in space; and on days 1, 4, and 25 after landing. Heart rate variability (HRV) parameters were obtained in the frequency domain. Measurements were performed in the control condition for 10 min and during a 5-min mental arithmetic stress task, consisting of deducting 17 from a four-digit number, read by a colleague, and orally announcing the result. Our results show that over all sessions (pre-, in-, and postflight), mental stress induced an average increase in mean heart rate (Δ7 ± 1 beats/min; P = 0.03) and mean arterial pressure (Δ7 ± 1 mmHg; P = 0.006). A sympathetic excitation during mental stress was shown from HRV parameters: increase of low frequency expressed in normalized units (Δ8.3 ± 1.4; P = 0.004) and low frequency/high frequency (Δ1.6 ± 0.3; P = 0.001) and decrease of high frequency expressed in normalized units (Δ8.9 ± 1.4; P = 0.004). The total power was not influenced by mental stress. No effect of spaceflight was found on baseline heart rate, mean arterial pressure, and HRV parameters. No differences in response to mental stress were found between pre-, in-, and postflight. Our findings confirm that a mental arithmetic task in astronauts elicits sympathovagal shifts toward enhanced sympathetic modulation and reduced vagal modulation. However, these responses are not changed in space during microgravity or after spaceflight.

Biological sensitivity to context: the interactive effects of stress reactivity and family adversity on socioemotional behavior and school readiness

This study examined the direct and interactive effects of stress reactivity and family adversity on socioemotional and cognitive development in three hundred and thirty-eight 5- to 6-year-old children. Neurobiological stress reactivity was measured as respiratory sinus arrhythmia and salivary cortisol responses to social, cognitive, sensory, and emotional challenges. Adaptation was assessed using child, parent, and teacher reports of externalizing symptoms, prosocial behaviors, school engagement, and academic competence. Results revealed significant interactions between reactivity and adversity. High stress reactivity was associated with more maladaptive outcomes in the context of high adversity but with better adaption in the context of low adversity. The findings corroborate a reconceptualization of stress reactivity as biological sensitivity to context by showing that high reactivity can both hinder and promote adaptive functioning.

Theory and method at the intersection of anthropology and cultural neuroscience

Anthropologists have become increasingly interested in embodiment-that is, the ways that socio-cultural factors influence the form, behavior and subjective experience of human bodies. At the same time, social cognitive neuroscience has begun to reveal the mechanisms of embodiment by investigating the neural underpinnings and consequences of social experience. Despite this overlap, the two fields have barely engaged one another. We suggest three interconnected domains of inquiry in which the intersection of neuroscience and anthropology can productively inform our understanding of the relationship between human brains and their socio-cultural contexts. These are: the social construction of emotion, cultural psychiatry, and the embodiment of ritual. We build on both current research findings in cultural neuroscience and ethnographic data on cultural differences in thought and behavior, to generate novel, ecologically informed hypotheses for future study. In addition, we lay out a specific suggestion for operationalizing insights from anthropology in the context of cultural neuroscience research. Specifically, we advocate the development of field studies that use portable measurement technologies to connect individual patterns of biological response with socio-cultural processes. We illustrate the potential of such an approach with data from a study of psychophysiology and religious devotion in Northeastern Brazil.

Autonomic activity and somatic symptoms in response to success vs. failure on a cognitive task: a comparison of chronic abdominal pain patients and well children

OBJECTIVES

To compare autonomic nervous system (ANS) activity and somatic symptoms in chronic abdominal pain (CAP) patients and well children during (a) resting baseline, (b) training in a cognitive task, and (c) random assignment to success vs. failure on the task.

METHODS

The ECG was continuously recorded with a dual lead system (Biopac) in 45 CAP patients and 22 well children, ages 9-16 years (mean age=12.3). Heart rate variability (HRV) was analyzed during the 5-min resting baseline, training, and success/failure on the task. Performance expectations were assessed before the task. Gastrointestinal (GI) and non-GI somatic symptoms were assessed before and after the task.

RESULTS

Compared to well children, CAP patients reported lower expectations for their task performance and higher GI symptoms (P's<.05). During success, CAP patients exhibited significant increases in both sympathetic (P<.05) and parasympathetic (P<.05) activity, whereas well children exhibited no change in ANS activity. During failure, CAP patients exhibited significant increases in somatic symptoms (<.05) but no change in ANS activity.

CONCLUSIONS

The lower performance expectations of CAP patients compared to well children may have influenced their experience of success and contributed to differences in their autonomic activity.

Cardiac autonomic control during simulated driving with a concurrent verbal working memory task

OBJECTIVE

The objective of the study was to illustrate sensitivity and diagnosticity differences between cardiac measures and lane-keeping measures of driving performance.

BACKGROUND

Previous research suggests that physiological measures can be sensitive to the effects of driving and side task performance and diagnostic of the source of the attentional demands. We hypothesized that increases in side task difficulty would elicit physiological change without reduction of driving task performance and that the side task demands would elicit patterns ofautonomic activity that map to specific attentional processing resources.

METHOD

Separately and concurrently, thirty-two participants performed a simulated driving task and verbal working memory task (with two levels of difficulty, 0 back and 3 back) separately and concurrently. Attentional demands were assessed through physiological and performance measures.

RESULTS

Cardiac measures reflected changes in attentional demand from single- to dual-task driving with an n-back task, whereas lane-keeping measures did not. Furthermore, patterns of autonomic activity elicited by driving, n-back task, and dual-task driving with a 3-back task were consistent with our predictions about autonomic activity.

CONCLUSION

Changes in cardiac measures without changes in lane-keeping measures provide evidence that cardiac measures can be sensitive to hidden costs in attention that do not manifest in coarse measures of driving performance. Furthermore, correct predictions regarding the patterns of autonomic activity elicited suggests that cardiac measures can serve as diagnostic tools for attention assessment.

APPLICATION

Because of the demonstrated differences in sensitivity and diagnosticity, researchers should consider the use of cardiac measures in addition to driving performance measures when studying attention in a driving simulator environment.

Physiological Profiles During Delay of Gratification: Associations with Emotionality, Self-regulation, and Adjustment Problems

This longitudinal study utilized a community sample of children (N=91, 45% female, 8-11 years at time 1) to investigate physiological responses (heart rate reactivity [HRR] and electrodermal responding [EDR]) during delay of gratification in relation to emotionality, self-regulation, and adjustment problems. Cluster analyses identified three profiles among children who successfully delayed: children who waited easily with low EDR and moderate HRR, children who had difficulty waiting with high EDR and moderate HRR, and children who had difficulty waiting with low EDR and low HRR. The 3 clusters and children who did not wait were compared. Children with low EDR-low HRR had the lowest self-regulation, and like the no-wait group, demonstrated the greatest baseline adjustment problems. The high EDR-moderate HRR group demonstrated highest self-regulation and increases in depression across one year. Distinct profiles among children in delay contexts point to children who are over- and under-regulated with implications for adjustment problems.

Autonomic Stress Response Modes and Ambulatory Heart Rate Level and Variability

The major goals of this study were (1) to determine consistency of autonomic response modes to different laboratory stressors, and (2) to evaluate the strength of the association between autonomic response modes and ambulatory heart rate and variability. The sample consisted of 45 healthy participants. Parasympathetic (PNS) and sympathetic (SNS) reactivity to and recovery from laboratory stressors (handgrip, logical-mathematical, mirror-tracing, and rumination tasks) were estimated by high frequency heart rate variability (HF-HRV), preejection period (PEP), and baroreflex sensitivity (BRS). Ambulatory HR was measured for 24 h on a work and a nonwork day, counterbalanced. As BRS was less reliable compared to PEP and HF-HRV, the latter two parameters were selected for the computation of SNS/PNS patterns. Autonomic modes were consistent across tasks and more stable during the recovery periods. Moreover, recovery appeared to be sensitive to the emotionality of tasks. Reactivity and recovery patterns differed as a function of gender, with women showing higher vagal tone at baseline, higher HR reactivity to the logical task, greater BRS decrease during the rumination task, and a larger decrease in vagal tone during recovery after the rumination task. After controlling for gender and baseline HR and variability, autonomic profiles during reactivity and recovery periods captured substantially different ambulatory information. Specifically, autonomic profiles during reactivity significantly predicted ambulatory HR level during waking hours, whereas autonomic profile during recovery was linked with ambulatory HRV. Coactivation of SNS and PNS activity was associated with the highest ambulatory HR levels and variability. Findings from the laboratory were consistent with a dimensional autonomic model viewing SNS and PNS contributions to heart rate on orthogonal axes and individual stress response stereotypy. Laboratory task-related autonomic reactivity and recovery may reflect parallel differences in HR level and variability in everyday life.

RSA fluctuation in major depressive disorder

Cardiac vagal control, as measured by indices of respiratory sinus arrhythmia (RSA), has been investigated as a marker of impaired self-regulation in mental disorders, including depression. Past work in depressed samples has focused on deficits in resting RSA levels, with mixed results. This study tested the hypothesis that depression involves abnormal RSA fluctuation. RSA was measured in depressed and healthy control participants during rest and during two reactivity tasks, each followed by a recovery period. Relative to controls, depressed persons exhibited lower resting RSA levels as well as less RSA fluctuation, primarily evidenced by a lack of task-related vagal suppression. Group differences in RSA fluctuation were not accounted for by differences in physical health or respiration, whereas group differences in resting RSA level did not survive covariate analyses. Depression may involve multiple deficits in cardiac vagal control.

Relationships Between Hostility, Affective Ratings of Pictures, and State Affects During Task-Induced Stress

The authors examined the relationship of hostility with (a) affective ratings of pictures and (b) state affects evoked by task-induced stress in 95 healthy men and women 22-37 years of age. Pictures were from the International Affective Picture System (IAPS; P. J. Lang, M. M. Bradley, & B. N. Cuthbert, 1999). Stressors included a startle task, mental arithmetic task, and choice-deadline reaction time task. The circumplex model of affect was used to structure the self-reported state affects. The authors found that hostility was associated with displeasure, high arousal, and low dominance ratings of IAPS pictures. Hostility was related to unpleasant affect and unactivated unpleasant affect during the experiment, and subscale paranoia was related to activated unpleasant affect. Findings suggest that participants scoring high on hostility are prone to negative emotional reactions.

Experiencing positive affect and negative affect during stress: relationships to cardiac reactivity and to facial expressions

We examined the relationship between experienced positive/negative affect and cardiac reactivity and facial muscle movements during laboratory tasks with different demands. Heart rate, respiratory sinus arrhythmia, pre-ejection period, and facial electromyography were measured during startle, mental arithmetic, reaction time task, and speech task. The results revealed that individuals experiencing high levels of positive affect exhibited more pronounced parasympathetic, heart rate, and orbicularis oculi reactivity than others. Individuals who experienced high levels of negative affects during the tasks showed higher corrugator supercilii responses. Men and women showed slightly different response patterns. To conclude, cardiac reactivity may be associated with positive involvement and enthusiasm in some situations and all reactivity should not automatically be considered as potentially pathological.

Methodological issues in the quantification of respiratory sinus arrhythmia

Although respiratory sinus arrhythmia (RSA) is a commonly quantified physiological variable, the methods for quantification are not consistent. This manuscript questions the assumption that respiration frequency needs to be manipulated or monitored to generate an accurate measure of RSA amplitude. A review of recent papers is presented that contrast RSA amplitude with measures that use respiratory parameters to adjust RSA amplitude. In addition, data from two studies are presented to evaluate empirically both the relation between RSA amplitude and respiration frequency and the covariation between RSA frequency and respiration frequency. The literature review demonstrates similar findings between both classes of measures. The first study demonstrates, during spontaneous breathing without task demands, that there is no relation between respiration frequency and RSA amplitude and that respiration frequency can be accurately derived from the heart period spectrum (i.e., frequency of RSA). The second study demonstrates that respiration frequency is unaffected by atropine dose, a manipulation that systematically mediates the amplitude of RSA, and that the tight linkage between the RSA frequency and respiration frequency is unaffected by atropine. The research shows that the amplitude of RSA is not affected by respiration frequency under either baseline conditions or vagal manipulation via atropine injection. Respiration frequency is therefore unlikely to be a concern under these conditions. Research examining conditions that produce (causal) deviations from the intrinsic relation between respiratory parameters and the amplitude of RSA combined with appropriate statistical procedures for understanding these deviations are necessary.