Orienting in a defensive world: mammalian modifications of our evolutionary heritage. A Polyvagal Theory

Biological systems and the development of self-regulation: integrating behavior, genetics, and psychophysiology

Self-regulation is the ability to control inner states or responses with respect to thoughts, emotions, attention, and performance. As such, it is a critical aspect of development and fundamental to personality and behavioral adjustment. In this review, we focus on attentional, cognitive, and emotional control as we discuss the genetic mechanisms and brain mechanisms that contribute to individual differences in self-regulation. We conclude with a discussion of the implications for deviations in the development of this complex construct and suggestions for future research.

Vagus nerve stimulation: indications and limitations

Vagus nerve stimulation (VNS) is an established treatment for selected patients with medically refractory seizures. Recent studies suggest that VNS could be potentially useful in the treatment of resistant depressive disorder. Although a surgical procedure is required in order to implant the VNS device, the possibility of a long-term benefit largely free of severe side effects could give VNS a privileged place in the management of resistant depression. In addition, VNS appears to affect pain perception in depressed adults; a possible role of VNS in the treatment of severe refractory headache, intractable chronic migraine and cluster headache has also been suggested. VNS is currently investigated in clinical studies, as a potential treatment for essential tremor, cognitive deficits in Alzheimer's disease, anxiety disorders, and bulimia. Finally, other studies explore the potential use of VNS in the treatment of resistant obesity, addictions, sleep disorders, narcolepsy, coma and memory and learning deficits.

Panic disorder, phobias, and generalized anxiety disorder

This chapter provides a review of recent empirical developments, current controversies, and areas in need of further research in relation to factors that are common as well as specific to the etiology and maintenance of panic disorder, phobias, and generalized anxiety disorder. The relative contribution of broad risk factors to these disorders is discussed, including temperament, genetics, biological influences, cognition, and familial variables. In addition, the role that specific learning experiences play in relation to each disorder is reviewed. In an overarching hierarchical model, it is proposed that generalized anxiety disorder, and to some extent panic disorder, loads most heavily on broad underlying factors, whereas specific life history contributes most strongly to circumscribed phobias.

Dissociation of sad facial expressions and autonomic nervous system responding in boys with disruptive behavior disorders

Although deficiencies in emotional responding have been linked to externalizing behaviors in children, little is known about how discrete response systems (e.g., expressive, physiological) are coordinated during emotional challenge among these youth. We examined time-linked correspondence of sad facial expressions and autonomic reactivity during an empathy-eliciting task among boys with disruptive behavior disorders (n=31) and controls (n=23). For controls, sad facial expressions were associated with reduced sympathetic (lower skin conductance level, lengthened cardiac preejection period [PEP]) and increased parasympathetic (higher respiratory sinus arrhythmia [RSA]) activity. In contrast, no correspondence between facial expressions and autonomic reactivity was observed among boys with conduct problems. Furthermore, low correspondence between facial expressions and PEP predicted externalizing symptom severity, whereas low correspondence between facial expressions and RSA predicted internalizing symptom severity.

The Role of Emotion Regulation in the Treatment of Child Anxiety Disorders

In this review, we examine the role of emotion regulation in the treatment of children with anxiety disorders. Cognitive-behavioral therapy (CBT) has been shown to "work" for children with anxiety disorders and it has been categorized as an evidence-based treatment. However, most studies have shown that the treatment is effective for about 60-70% of children, leaving the remaining children symptomatic and oftentimes with persisting psychological disorders. Of importance, it has also been shown that many children with anxiety disorders demonstrate poor emotion regulation skills. Despite these findings, little attention has been directed toward incorporating emotion regulation strategies into these relatively effective cognitive-behavioral treatments. It is possible that CBT programs do not work as well for a portion of children because their emotion regulation deficits, if present, are not being targeted sufficiently. In this review, it is suggested that adding an emotion regulation component could increase treatment efficacy. In addition, strategies aimed at improving emotion regulation at the individual level and at the family level are introduced. Details of how improved emotion regulation skills could be beneficial in bringing about change are discussed. Finally, issues of measurement and the clinical implications for research and practice are considered.

Borderline personality disorder and emotion regulation: insights from the Polyvagal Theory

The current study provides the first published evidence that the parasympathetic component of the autonomic nervous system differentiates the response profiles between individuals diagnosed with borderline personality disorder (BPD) and controls. Respiratory sinus arrhythmia (RSA), a non-invasive marker of the influence of the myelinated vagal fibers on the heart, and heart period were collected during the presentation of film clips of varying emotional content. The BPD and control groups had similar initial levels of RSA and heart period. However, during the experiment the groups exhibited contrasting trajectories, with the BPD group decreasing RSA and heart period and the control group increasing RSA and heart period. By the end of the experiment, the groups differ significantly on both RSA and heart period. The correlation between the changes in RSA and heart period was significant only for the control group, suggesting that vagal mechanisms mediated the heart period responses only in the control group. The findings were consistent with the Polyvagal Theory [Porges, S. W. (1995). Orienting in a defensive world: Mammalian modifications of our evolutionary heritage: A Polyvagal Theory. Psychophysiology, 32, 301-318; Porges, S. W. (2001). The Polyvagal Theory: Phylogenetic substrates of a social nervous system. International Journal of Psychophysiology, 42, 123-146; Porges, S. W. (2003). Social engagement and attachment: A phylogenetic perspective. Annals of the New York Academy of Sciences, 1008, 31-47.], illustrating different adaptive shifts in autonomic state throughout the course of the experiment. The BPD group ended in a physiological state that supports the mobilization behaviors of fight and flight, while the control group ended in a physiological state that supports social engagement behaviors. These finding are consistent with other published studies demonstrating atypical vagal regulation of the heart with other psychiatric disorders.

Cardiac vagal regulation and early peer status

A sample of 341 5 (1/2) -year-old children participating in an ongoing longitudinal study was the focus of a study on the relation between cardiac vagal regulation and peer status. To assess cardiac vagal regulation, resting measures of respiratory sinus arrhythmia (RSA) and RSA change (suppression) to 3 cognitively and emotionally challenging tasks were derived. Results indicated that vagal regulation was positively associated with peer status. In addition, mediational analyses revealed that the relation between vagal regulation and peer status was mediated through better social skills for girls and better social skills and fewer behavior problems for boys. These findings are discussed in terms of the role of vagal regulation in the facilitation of children's positive social behavior.

Interrupting the cascade: Orienting contributes to decision making even in the absence of visual stimulation

Most systematic studies of human decision making approach the subject from a cost analysis point of view and assume that people make the highest utility choice. Very few articles investigate subjective decision making, such as that involving preference, although such decisions are very important for our daily functioning. We have argued (Shimojo, Simion, Shimojo, & Scheier, 2003) that an orienting bias effectively leads to the preference decision by means of a positive feedback loop involving mere exposure and preferential looking. The illustration of this process is a continually increasing gaze bias toward the eventual choice, which we call the gaze cascade effect. In the present study, we interrupt the natural process of preference selection, but we show that gaze behavior does not change even when the stimuli are removed from observers' visual field. This demonstrates that once started, the involvement of orienting in decision making cannot be stopped and that orienting acts independently of the presence of visual stimuli. We also show that the cascade effect is intrinsically linked to the decision itself and is not triggered simply by a tendency to look at preferred targets.

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.

Prenatal cocaine and other substance exposure: effects on infant autonomic regulation at 7 months of age

This study examined the association between prenatal exposure to cocaine and autonomic regulation at 7 months of age. Heart rate (HR) and respiratory sinus arrhythmia (RSA) were obtained from 154 (79 exposed, and 75 nonexposed) infants during baseline and tasks designed to elicit positive and negative affect. Cocaine-exposed infants had higher HR during the positive affect task. There was a significant suppression of RSA during the negative affect task for nonexposed infants but not for exposed infants. Fetal growth and maternal caregiving behavior did not mediate or moderate this association. These results provide additional support for an association between prenatal cocaine exposure and dysregulation during infancy.

Sex differences in cardiac vagal control in a depressed sample: implications for differential cardiovascular mortality

Previous studies suggest depression is a risk factor for all cause mortality, with depressed men at greater risk than depressed women. Diminished cardiac vagal control (CVC) in depressed patients has also been found to increase risk of cardiac mortality. Previous research found that depressed women have higher CVC than depressed men suggesting CVC might be related to the discrepancy in mortality rates between depressed men and women. This finding, however, was in the context of a study with several methodological weaknesses. The current study sought to replicate the sex difference in CVC in a sample of 137 medically healthy and clinically diagnosed depressed patients. Main effects of sex and age significantly predicted CVC such that depressed women had greater CVC and CVC decreased with age in the cross-sectional sample. The results suggest greater CVC in depressed women might confer cardioprotective functions, which may partially explain the sex difference in mortality rates in the depressed population.

Psychological factors associated with orofacial pains

This article develops the case for why trigeminal pain is a unique and challenging problem for clinicians and patients alike, and provides the reader with insights for effective trigeminal pain management based on an understanding of the interplay between psychologic and physiologic systems. There is no greater sensory experience for the brain to manage than unremitting pain in trigeminally mediated areas. Such pain overwhelms conscious experience and focuses the suffering individual like few other sensory events. Trigeminal pain often motivates a search for relief that can drain financial and emotional resources. In some instances, the search is rewarded by a treatment that immediately addresses an identifiable source of pain; in other cases, it can stimulate never-ending pilgrimages from one health provider to another.

Does respiratory sinus arrhythmia occur in fishes?

The hypothesis that respiratory modulation of heart rate variability (HRV) or respiratory sinus arrhythmia (RSA) is restricted to mammals was tested on four Antarctic and four sub-Antarctic species of fish, that shared close genotypic or ecotypic similarities but, due to their different environmental temperatures, faced vastly different selection pressures related to oxygen supply. The intrinsic heart rate (fH) for all the fish species studied was approximately 25% greater than respiration rate (fV), but vagal activity successively delayed heart beats, producing a resting fH that was synchronized with fV in a progressive manner. Power spectral statistics showed that these episodes of relative bradycardia occurred in a cyclical manner every 2-4 heart beats in temperate species but at >4 heart beats in Antarctic species, indicating a more relaxed selection pressure for cardio-respiratory coupling. This evidence that vagally mediated control of fH operates around the ventilatory cycle in fish demonstrates that influences similar to those controlling RSA in mammals operate in non-mammalian vertebrates.

Response of fetal heart rate to uterine contractions

The heart rate variability of fetuses under stress from maternal uterine contractions conveys critical information to clinicians and also provides theoretical clues about heart rate regulatory mechanisms. According to the polyvagal theory, the deceleration of fetal heart rate under stress is caused by the withdrawal of vagal tone. Recovery is mediated by its reestablishment. An implication of this mechanism is that the respiratory sinus arrhythmia (RSA) is elevated after the deceleration and subsequent recovery. Findings from our clinical data on fetuses support this theory. The data also indicate that in the instance of a late deceleration the RSA may not be elevated after recovery.

Infant and parent factors associated with early maternal sensitivity: A caregiver-attachment systems approach

We examined variations in maternal sensitivity at 6 months of child age as a function of child negativity and maternal physiology. We expected maternal vagal withdrawal in response to infant negative affect to facilitate the maintenance of sensitivity, but only for mothers of securely attached children. One hundred and forty-eight infant-mother dyads were observed in multiple contexts at 6 months of child age, and associations among maternal and child variables were examined with respect to 12-month attachment quality. Mothers of later securely attached children were more sensitive than mothers of avoidant children. However, sensitivity decreased for all mothers at high levels of infant negative affect. Furthermore, for mothers of avoidant children, vagal withdrawal was associated with sensitivity to child distress. No association was found between vagal withdrawal and sensitivity for mothers of securely attached children. This suggests that mothers of avoidant children may be uniquely challenged by the affective demands of their infants.

An autonomic flexibility–neurovisceral integration model of anxiety and cardiac vagal tone

Research on heart rate variability (HRV), cardiac vagal tone, and their relationship to anxiety is reviewed in the context of the autonomic flexibility and neurovisceral integration models of adaptive functioning. These perspectives address the qualities of response flexibility and inhibition across multiple levels, incorporating central and autonomic nervous system mechanisms of environmental engagement, as well as principles derived from non-linear dynamics. These models predict reduced HRV and vagal tone in anxiety, and the literature has generally supported this prediction, with exceptions as are noted. State, trait, and clinical expressions of anxiety are considered, along with the clinical, methodological, and theoretical implications of this research. A portrayal of anxiety as a restricted response range across biological and behavioral realms of functioning is drawn from the literature on anxiety and HRV.

Estimated cardiac vagal tone predicts fetal responses to mother's and stranger's voices

Heart rate responses of 84 near-term fetuses to recorded female voices were examined in 166 trials of auditory stimulation. Each fetus was presented with a 2-min recording of their mother's voice and a 2-min recording of a female stranger's voice, in counterbalanced order, with a 10-min rest period between trials. High frequency heart rate variability during a 2-min baseline period was used to estimate cardiac vagal tone for each trial. Differential heart rate responses to familiar and unfamiliar voice recordings were observed during a 2-min poststimulus period, only when estimated cardiac vagal tone was high. This finding suggests that vagal tone plays a moderating role in the cardiac responses of term fetuses to familiar and unfamiliar stimuli.

Respiratory sinus arrhythmia as a function of state anxiety in healthy individuals

Respiratory sinus arrhythmia (RSA) was examined in relation to state and trait anxiety in healthy individuals. Time-frequency analyses of HR-power spectrum in the high frequency region (0.12-0.40 Hz), related to RSA, were examined in 43 women and 39 men. Based on median split, the participants were divided into high and low state and trait anxiety groups. The main result showed that high state anxious individuals had higher RSA-magnitude (HF-power) than low state anxious individuals. The higher RSA-magnitude in the former group was interpreted as reflecting increased attention or vigilance together with motor and behavioural inhibition. No significant effects of trait anxiety or gender were found.

Physiological responses of 5-month-old infants to smiling and blank faces

Physiological responses (i.e., EEG, heart period, respiratory sinus arrhythmia (RSA)) were monitored in 5-month-old infants during the replacement of an adult's smiling (SF) with a blank face (BF) in a face-to-face setting. Affect, while the infant looked at and away from the adult's face during both conditions, was analyzed. Infants displayed neutral and some positive affect while looking at both SF and BF. RSA was quantified continuously during both conditions. RSA increased during BF relative to SF. EEG was quantified only while the infants were looking at the adult's face during both conditions. An increase in theta over multiple scalp areas (AF3,4; F7,8; FC3; T6) was observed during BF relative to SF. The data suggest that infant attention to BF and SF reflect different psychophysiological processes that can be indexed by RSA and scalp-recorded theta.

Characteristics of resonance in heart rate variability stimulated by biofeedback

As we previously reported, resonant frequency heart rate variability biofeedback increases baroreflex gain and peak expiratory flow in healthy individuals and has positive effects in treatment of asthma patients. Biofeedback readily produces large oscillations in heart rate, blood pressure, vascular tone, and pulse amplitude via paced breathing at the specific natural resonant frequency of the cardiovascular system for each individual. This paper describes how resonance properties of the cardiovascular system mediate the effects of heart rate variability biofeedback. There is evidence that resonant oscillations can train autonomic reflexes to provide therapeutic effect. The paper is based on studies described in previous papers. Here, we discuss the origin of the resonance phenomenon, describe our procedure for determining an individual's resonant frequency, and report data from 32 adult asthma patients and 24 healthy adult subjects, showing a negative relationship between resonant frequency and height, and a lower resonant frequency in men than women, but no relationship between resonant frequency and age, weight, or presence of asthma. Resonant frequency remains constant across 10 sessions of biofeedback training. It appears to be related to blood volume.

Domestic violence and vagal reactivity to peer provocation

This paper examined whether individual differences in children's vagal reactivity to peer provocation were related to domestic violence within the family. It also examined the question of whether conduct-problem children who show vagal augmentation to peer provocation come from families with high levels of domestic violence. During the peer provocation, children were expecting to interact with a difficult peer while vagal reactivity was assessed. Groups were divided into children who showed vagal augmentation and vagal suppression to the stressful peer interaction. Findings indicated that conduct-problem children who showed vagal augmentation to interpersonal challenge came from families with the highest levels of domestic violence. Vagal augmentation was also associated with a greater number of conduct-related problems for those children exposed to high levels of domestic violence. Discussion highlights the role of individual differences in physiological reactivity in understanding children's behavior problems in relation to domestic violence.

Toward understanding respiratory sinus arrhythmia: relations to cardiac vagal tone, evolution and biobehavioral functions

Respiratory sinus arrhythmia (RSA, or high-frequency heart-rate variability) is frequently employed as an index of cardiac vagal tone or even believed to be a direct measure of vagal tone. However, there are many significant caveats regarding vagal tone interpretation: 1. Respiratory parameters can confound relations between RSA and cardiac vagal tone.2. Although intraindividual relations between RSA and cardiac vagal control are often strong, interindividual associations may be modest.3. RSA measurement is profoundly influenced by concurrent levels of momentary physical activity, which can bias estimation of individual differences in vagal tone.4. RSA magnitude is affected by beta-adrenergic tone.5. RSA and cardiac vagal tone can dissociate under certain circumstances.6. The polyvagal theory contains evolution-based speculations that relate RSA, vagal tone and behavioral phenomena. We present evidence that the polyvagal theory does not accurately depict evolution of vagal control of heart-rate variability, and that it ignores the phenomenon of cardiac aliasing and disregards the evolution of a functional role for vagal control of the heart, from cardiorespiratory synchrony in fish to RSA in mammals. Unawareness of these issues can lead to misinterpretation of cardiovascular autonomic mechanisms. On the other hand, RSA has been shown to often provide a reasonable reflection of cardiac vagal tone when the above-mentioned complexities are considered. Finally, a recent hypothesis is expanded upon, in which RSA plays a primary role in regulation of energy exchange by means of synchronizing respiratory and cardiovascular processes during metabolic and behavioral change.

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.

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.

A phylogenetic journey through the vague and ambiguous Xth cranial nerve: a commentary on contemporary heart rate variability research

Contemporary heart rate variability research is discussed within a historical context. Implicit in this history is the discovery that the central nervous system regulates the heart and how information regarding neural regulation of the heart is imbedded in the beat-to-beat heart rate pattern. As methodologies have become more sensitive to neural regulation and as theories have expanded to integrate behavior and psychological processes with neurobiological principles, researchers are becoming better positioned to successfully understand how neurovisceral processes mediate the expression of health and disease. The contributions to this special issue describe research representing different levels of scientific inquiry and focus on different features of the complex neural feedback system that are manifested in the robust relationships between heart rate variability and several behavioral, psychological, physiological, and health processes. This article provides a commentary to these contributions.

The polyvagal perspective

The polyvagal theory introduced a new perspective relating autonomic function to behavior, that included an appreciation of the autonomic nervous system as a "system," the identification of neural circuits involved in the regulation of autonomic state, and an interpretation of autonomic reactivity as adaptive within the context of the phylogeny of the vertebrate autonomic nervous system. The paper has two objectives: first, to provide an explicit statement of the theory; and second, to introduce the features of a polyvagal perspective. The polyvagal perspective emphasizes how an understanding of neurophysiological mechanisms and phylogenetic shifts in neural regulation leads to different questions, paradigms, explanations, and conclusions regarding autonomic function in biobehavioral processes than peripheral models. Foremost, the polyvagal perspective emphasizes the importance of phylogenetic changes in the neural structures regulating the autonomic nervous system and how these phylogenetic shifts provide insights into the adaptive function and the neural regulation of the two vagal systems.

Polyvagal Theory and developmental psychopathology: emotion dysregulation and conduct problems from preschool to adolescence

In science, theories lend coherence to vast amounts of descriptive information. However, current diagnostic approaches in psychopathology are primarily atheoretical, emphasizing description over etiological mechanisms. We describe the importance of Polyvagal Theory toward understanding the etiology of emotion dysregulation, a hallmark of psychopathology. When combined with theories of social reinforcement and motivation, Polyvagal Theory specifies etiological mechanisms through which distinct patterns of psychopathology emerge. In this paper, we summarize three studies evaluating autonomic nervous system functioning in children with conduct problems, ages 4-18. At all age ranges, these children exhibit attenuated sympathetic nervous system responses to reward, suggesting deficiencies in approach motivation. By middle school, this reward insensitivity is met with inadequate vagal modulation of cardiac output, suggesting additional deficiencies in emotion regulation. We propose a biosocial developmental model of conduct problems in which inherited impulsivity is amplified through social reinforcement of emotional lability. Implications for early intervention are discussed.

Cardiac vagal control in depression: a critical analysis

Rapidly developing research has found abnormal cardiac vagal control (CVC) in several physical and mental health conditions. CVC findings in depression are mixed, and the degree to which CVC is compromised in depression is unclear. A meta-analysis of 13 rigorous cross-sectional studies reveals that a diagnosis of depression exerts a small-to-medium effect size on CVC, and explains only about 2% of the overall variance in CVC. More robust data may emerge from alternative approaches to the depression-CVC relationship, such as the use of CVC to predict the course of the disorder. Despite the vigor of recent work on CVC and depression, overall findings are suggestive rather than conclusive. Methodological desiderata and priorities for future research are discussed, including the need to clarify the etiological significance of CVC.

Respiratory sinus arrhythmia, emotion, and emotion regulation during social interaction

Respiratory sinus arrhythmia (RSA) figures prominently in emotional responding, but its exact role remains unclear. The present study tests two hypotheses: (1) Between-person differences in resting RSA are related to emotional reactivity, and (2) within-person changes in RSA are related to regulatory efforts. Pairs of women watched an upsetting film and discussed it. One woman in each of the experimental dyads was asked to either suppress or to reappraise during the conversation. Their partners and both members of the control dyads conversed naturally. Between-person differences in resting RSA were assessed with paced breathing, and within-person changes in RSA were calculated from baseline to the conversation accounting for respiration. Women with higher resting RSA experienced and expressed more negative emotion, and women who attempted to regulate their emotions either by suppressing or reappraising showed larger increases in RSA than controls.

Clinical implications of neuroscience research in PTSD

The research showing how exposure to extreme stress affects brain function is making important contributions to understanding the nature of traumatic stress. This includes the notion that traumatized individuals are vulnerable to react to sensory information with subcortically initiated responses that are irrelevant, and often harmful, in the present. Reminders of traumatic experiences activate brain regions that support intense emotions, and decrease activation in the central nervous system (CNS) regions involved in (a) the integration of sensory input with motor output, (b) the modulation of physiological arousal, and (c) the capacity to communicate experience in words. Failures of attention and memory in posttraumatic stress disorder (PTSD) interfere with the capacity to engage in the present: traumatized individuals "lose their way in the world." This article discusses the implications of this research by suggesting that effective treatment needs to involve (a) learning to tolerate feelings and sensations by increasing the capacity for interoception, (b) learning to modulate arousal, and (c) learning that after confrontation with physical helplessness it is essential to engage in taking effective action.

Ghrelin concentrations and cardiac vagal tone are decreased after pharmacologic and cognitive-behavioral treatment in patients with bulimia nervosa

Patients with bulimia nervosa (BN) have bulimic and depressive symptoms, which have been associated with abnormalities in the neuroendocrine and vagal systems. Subjects included twenty-four female drug-free outpatients with BN that were selected from patients seeking treatment for eating behavior in our hospital along with twenty-five age-matched healthy females who served as controls. We investigated ghrelin and leptin levels, cardiac vagal tone and sympathovagal balance, frequency of sets of binge-eating and vomiting episodes per week and the Profile of Mood States (POMS) depression scale in BN before and after a 16-week administration of the serotonin selective reuptake inhibitor (SSRI) paroxetine combined with cognitive-behavioral therapy. Compared to controls, the BN group had higher ghrelin levels and resting cardiac vagal tone, and lower leptin levels and resting cardiac sympathovagal balance before treatment, although there was a significant difference between the two groups for the body mass index (BMI). The elevated ghrelin levels (301.7 +/- 18.9 pmol/l, mean +/- SEM vs. 202.8 +/- 15.6 pmol/l, P < 0.01), cardiac vagal tone (2246.4 +/- 335.5 ms(2) vs. 1128.5 +/- 193.3 ms(2), P < 0.01), frequency of sets of binge-eating and purging episodes and T scores for the POMS depression scale were all significantly decreased after treatment despite similar BMI, percent body fat and leptin levels. In close association with cardiac vagal function and ghrelin recoveries, abnormal eating behavior and depressive symptoms improved, indicating the usefulness of these indexes in the assessment of clinical condition and therapeutic efficacy in BN.

Evidence for a respiratory component, similar to mammalian respiratory sinus arrhythmia, in the heart rate variability signal from the rattlesnake,Crotalus durissus terrificus

Autonomic control of heart rate variability and the central location of vagal preganglionic neurones (VPN) were examined in the rattlesnake(Crotalus durissus terrificus), in order to determine whether respiratory sinus arrhythmia (RSA) occurred in a similar manner to that described for mammals. Resting ECG signals were recorded in undisturbed snakes using miniature datalogging devices, and the presence of oscillations in heart rate (fh) was assessed by power spectral analysis (PSA). This mathematical technique provides a graphical output that enables the estimation of cardiac autonomic control by measuring periodic changes in the heart beat interval. At fh above 19 min-1spectra were mainly characterised by low frequency components, reflecting mainly adrenergic tonus on the heart. By contrast, at fhbelow 19 min-1 spectra typically contained high frequency components, demonstrated to be cholinergic in origin. Snakes with a fh &gt;19 min-1 may therefore have insufficient cholinergic tonus and/or too high an adrenergic tonus acting upon the heart for respiratory sinus arrhythmia (RSA) to develop. A parallel study monitored fh simultaneously with the intraperitoneal pressures associated with lung inflation. Snakes with a fh&lt;19 min-1 exhibited a high frequency (HF) peak in the power spectrum,which correlated with ventilation rate (fv). Adrenergic blockade by propranolol infusion increased the variability of the ventilation cycle, and the oscillatory component of the fh spectrum broadened accordingly. Infusion of atropine to effect cholinergic blockade abolished this HF component, confirming a role for vagal control of the heart in matching fh and fv in the rattlesnake. A neuroanatomical study of the brainstem revealed two locations for vagal preganglionic neurones (VPN). This is consistent with the suggestion that generation of ventilatory components in the heart rate variability (HRV)signal are dependent on spatially distinct loci for cardiac VPN. Therefore,this study has demonstrated the presence of RSA in the HRV signal and a dual location for VPN in the rattlesnake. We suggest there to be a causal relationship between these two observations.

Autonomic correlates of attention-deficit/hyperactivity disorder and oppositional defiant disorder in preschool children

Numerous studies have revealed autonomic underarousal in conduct-disordered adolescents and antisocial adults. It is unknown, however, whether similar autonomic markers are present in at-risk preschoolers. In this study, the authors compared autonomic profiles of 4- to 6-year-old children with attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD; n = 18) with those of age-matched controls (n = 20). Children with ADHD and ODD exhibited fewer electrodermal responses and lengthened cardiac preejection periods at baseline and during reward. Although group differences were not found in baseline respiratory sinus arrhythmia, heart rate changes among ADHD and ODD participants were mediated exclusively by parasympathetic withdrawal, with no independent sympathetic contribution. Heart rate changes among controls were mediated by both autonomic branches. These results suggest that at-risk preschoolers are autonomically similar to older externalizing children.

Neural mechanisms of autonomic, affective, and cognitive integration

Influential theoretical models propose a central role for afferent information from the body in the expression of emotional feeling states. Feedback representations of changing states of bodily arousal influence learning and facilitate concurrent and prospective decision-making. Functional neuroimaging studies have increased understanding of brain mechanisms that generate changes in autonomic arousal during behavior and those which respond to internal feedback signals to influence subjective feeling states. In particular, anterior cingulate cortex is implicated in generating autonomic changes, while insula and orbitofrontal cortices may be specialized in mapping visceral responses. Independently, ventromedial prefrontal cortex is recognized to support processes of internal (self-) reference that predominate in states of rest and disengagement and which putatively serve as a benchmark for dynamic interactions with the environment. Lesion data further highlight the integrated role of these cortical regions in autonomic and motivational control. In computational models of control, forward (efference copies) and inverse models are proposed to enable prediction and correction of action and, by extension, the interpretation of the behavior of others. It is hypothesized that the neural substrate for these processes during motivational and affective behavior lies within the interactions of anterior cingulate, insula, and orbitofrontal cortices. Generation of visceral autonomic correlates of control reinforce experiential engagement in simulatory models and underpin concepts such as somatic markers to bridge the dualistic divide.

Airways, respiration, and respiratory sinus arrhythmia during picture viewing

Emotional stimuli can cause airway constriction; however, it is uncertain whether a dimensional or categorical model of emotion can better describe airway changes. Also, little is known about the affective modulation of respiration and vagal activity, which can influence airway tone. We studied changes in oscillatory resistance (Ros), respiration, and respiratory sinus arrhythmia (RSA) in asthmatics and controls during viewing of affective pictures eliciting anxiety, depression, disgust, happiness, contentment, erotic tension, or neutral affect. Ros, respiration, cardiac activity, and self-report were measured during picture presentations. Ros increased monotonically with picture unpleasantness mainly due to disgust pictures. RSA and respiratory timing parameters were particularly sensitive to erotic pictures. Differences between asthmatics and controls were minimal, suggesting that airway responses to unpleasant pictures are not specific to asthma.

Autonomic reactivity and clinical severity in children with sickle cell disease

Individual differences in autonomic nervous system reactivity have been studied in relation to physical and mental health outcomes, but rarely among children with chronic disease. The purpose of this study was to examine the associations among autonomic reactivity, clinical severity, family stressors, and mental health symptoms in children with homozygous sickle cell disease. Nineteen children with homozygous sickle cell disease participated in a cross-sectional study involving parent-completed measures, medical record reviews and laboratory-based measures of autonomic nervous system responses to social, cognitive, physical and emotional challenges. Autonomic reactivity was significantly associated with both clinical severity and externalizing behavior symptoms. Children with greater parasympathetic withdrawal during challenges compared to rest had significantly more severe disease (r = -0.45, p < 0.05); greater sympathetic activation during challenges compared to rest was associated with more externalizing behavior symptoms ( r= 0.44, p < 0.05). Children experiencing major family stressors had internalizing behavior symptoms but no difference in autonomic reactivity or clinical severity compared to children experiencing fewer family stressors. Individual differences in autonomic reactivity may offer a new, biologically plausible account for observed variation in painful episodes, other physical complications and behavioral symptoms among children with sickle cell disease.

Prolonged (48-hour) modest hyperinsulinemia decreases nocturnal heart rate variability and attenuates the nocturnal decrease in blood pressure in lean, normotensive humans

CONTEXT

Heart rate variability (HRV), an index of cardiac vagal activity, is decreased in individuals with metabolic disease. The relationship between decreased HRV and metabolic disease is unclear.

OBJECTIVE

The objective of this study was to determine whether experimentally induced glucose intolerance decreases HRV in a circadian relevant manner in healthy individuals.

DESIGN

This was a within-subject, randomized design study with subjects infused for 48 h with saline (50 ml/h) or 15% glucose (200 mg/m2.min). HRV was evaluated using time domain measurements taken over the 48-h period. Blood pressure and heart rate were monitored, and blood samples were taken.

SETTING

This study was performed at the General Clinical Research Center of the Hospital of the University of Pennsylvania.

PATIENTS

Sixteen healthy subjects (eight men and eight women; 18-30 yr old; mean body mass index, 21.7 +/- 1.6 kg/m2) were studied.

RESULTS

After glucose infusion, mean plasma glucose was increased by 16.8% (P < 0.0001), and plasma insulin was increased by 99.4% (P < 0.0001) compared with after saline infusion. Significant decreases in homeostasis model assessment indicated a decrease in insulin sensitivity (saline, 0.52 + 0.13; glucose, 0.34 + 0.12; P < 0.0001). The nocturnal root mean square successive difference, an index of cardiac vagal activity, was significantly decreased (P < 0.01), and nocturnal HR (P < 0.001) and blood pressure were significantly elevated (saline, 107.4 +/- 2.7; glucose, 112.5 +/- 3.3 mm Hg; P < 0.05) compared with the saline control. The change in homeostasis model assessment due to glucose infusion was significantly correlated with the change in root mean square successive difference (r = 0.48; P < 0.01).

CONCLUSIONS

Prolonged mild hyperinsulinemia disrupts the circadian rhythm of cardiac autonomic activity. Early changes in the neural control of cardiac activity may provide a potential mechanism mediating the pathophysiological link between impaired glucose tolerance and cardiovascular disease.

Domestic violence, emotion coaching, and child adjustment

This article addresses the question of whether parents in domestically violent homes have difficulty talking to and helping their children manage their emotions-what has been referred to as emotion coaching. Emotion coaching as a moderator in the relationship between domestic violence (DV) and children's behavior problems was also examined. Results indicated that DV was not associated with a general deficit in emotion coaching but that DV was associated with less coaching of anger and fear depending on whether the parent was the perpetrator or victim of DV. Emotion coaching also moderated the relationship between DV and children's behavior problems. Implications for the development of an intervention program to improve parental coaching of emotion in domestically violent homes is discussed.

From biological rhythms to social rhythms: Physiological precursors of mother-infant synchrony

Links between neonatal biological rhythms and the emergence of interaction rhythms were examined in 3 groups (N = 71): high-risk preterms (HR; birth weight <1,000 g), low-risk preterms (LR; birth weight =1,700-1,850 g), and full-term (FT) infants. Once a week for premature infants and on the 2nd day for FT infants, sleep-wake cyclicity was extracted from 4-hr observations and cardiac vagal tone was measured. At term age, infant orientation was tested with the Neonatal Behavior Assessment Scale. At 3 months, arousal modulation and emotion regulation were assessed, and mother-infant synchrony was computed from microanalysis of face-to-face interactions using time-series analysis. Sleep-wake amplitudes showed a developmental leap at 31 weeks gestation, followed by a shift in vagal tone at 34 weeks gestation. At term, differences among FT, LR, and HR infants were observed for biological rhythms in a linear-decline pattern. Sleep-wake cyclicity, vagal tone, newborn orientation, and arousal modulation were each uniquely predictive of mother-infant synchrony. The organization of physiological oscillators appears to lay the foundation for the infant's capacity to partake in a temporally matched social dialogue.

Attentive Perception Can Diminish Vagal Inhibition

A systematic decrease in heart rate when anticipating an important stimulus or when preparing to react is called anticipatory bradycardia. Numerous studies have shown that the initiation of motor activity prompts the termination of anticipatory bradycardia in reaction time tasks. However, in experiments with procedures based on more complex reactions, the termination of anticipatory bradycardia is delayed until later cardiac cycles. This unexpected effect may be attributed to perceptual processes that are engaged in the feedback mechanism essential for effectiveness in prolonged and complex motor reactions. The experiment presented in this article was carried out to verify the hypothesis that the initiation of a motor reaction, when processed simultaneously with sustained attentive perception, does not evoke acceleration of heart rate. The experimental task was a simulated shooting at a moving target. The procedure in the experimental group induced participants to attentively observe events before and after the required reaction, whereas in the control group, attentive perception of task events after the reaction was not possible. The expected pattern of heart-rate changes appeared in the experimental group. During the initial block of trials, the initiation of the motor reaction did not evoke immediate termination of anticipatory bradycardia. During later trials in the experimental group and during all trials in the control group, heart-rate changes were completely typical - heart rate increased after the motor reaction began. The results show that attentive perception engaged immediately after the initiation of motor activity can affect the pattern of phasic heart-rate changes observed during typical reaction time tasks. Additionally, the difference between the patterns characteristic of the initial and later trials suggests possible competition between the neuronal influences that modulate heart rate.

Psychological, autonomic, and serotonergic correlates of parasuicide among adolescent girls

Although parasuicidal behavior in adolescence is poorly understood, evidence suggests that it may be a developmental precursor of borderline personality disorder (BPD). Current theories of both parasuicide and BPD suggest that emotion dysregulation is the primary precipitant of self-injury, which serves to dampen overwhelmingly negative affect. To date, however, no studies have assessed endophenotypic markers of emotional responding among parasuicidal adolescents. In the present study, we compare parasuicidal adolescent girls (n=23) with age-matched controls (n=23) on both psychological and physiological measures of emotion regulation and psychopathology. Adolescents, parents, and teachers completed questionnaires assessing internalizing and externalizing psychopathology, substance use, trait affectivity, and histories of parasuicide. Psychophysiological measures including electrodermal responding (EDR), respiratory sinus arrhythmia, and cardiac pre-ejection period (PEP) were collected at baseline, during negative mood induction, and during recovery. Compared with controls, parasuicidal adolescents exhibited reduced respiratory sinus arrhythmia (RSA) at baseline, greater RSA reactivity during negative mood induction, and attenuated peripheral serotonin levels. No between-group differences on measures of PEP or EDR were found. These results lend further support to theories of emotion dysregulation and impulsivity in parasuicidal teenage girls.

Mediated paths to over-reactive discipline: mothers' experienced emotion, appraisals, and physiological responses

The present investigation was designed to evaluate whether mothers' emotion experience, autonomic reactivity, and negatively biased appraisals of their toddlers' behavior and toddlers' rates of misbehavior predicted over-reactive discipline in a mediated fashion. Ninety-three community mother-toddler dyads were observed in a laboratory interaction, after which mothers' emotion experience and appraisals of their toddler's behavior were measured via a video-recall procedure. Autonomic physiology and over-reactive discipline were measured during the interactions. Mothers' negatively biased appraisals mediated the relation between emotion experience and over-reactive discipline. Heart rate reactivity predicted discipline independent of this mediation. Toddler misbehavior appeared to be an entry point into the above process. Interventions that more actively target physiological and experiential components of mothers' emotion may further reduce their over-reactive discipline.

Anterior cingulate activity during error and autonomic response

The contribution of anterior cingulate cortex (ACC) to human cognition remains unclear. The rostral (rACC) and dorsal (dACC) ACC cortex are implicated in tasks that require increased response control due to emotional and cognitive interference, respectively. However, both rACC and dACC are activated by conditions that induce changes in visceral arousal, suggesting that ACC supports a generation of integrated bodily responses. To clarify the relationship between purely cognitive and psychophysiological accounts of ACC function, we scanned 15 subjects using functional magnetic resonance imaging while they performed numerical versions of the Stroop task. To index autonomic arousal, we simultaneously measured pupil diameter. Performance errors accounted for most of the variance in a pupil-derived measure of evoked autonomic arousal. In analysis of the functional imaging data, activity within a region spanning rACC and dACC predicted trial-by-trial variation in autonomic response magnitude and was enhanced during error trials, shown using conjunction analyses. Activity within other loci within rACC predicted evoked autonomic arousal and showed sensitivity to errors but did not meet criteria for both. These data highlight the role of ACC in psychophysiological aspects of error processing and suggest that an interface exists within ACC between cognitive and biobehavioral systems in the service of response adaptation.