How good are patients with panic disorder at perceiving their heartbeats?

Vague sensations. About the background and consequences of discordance between actual and perceived physiological changes

Empirical evidence consistently shows that discordance, also called dissociation or discrepancy, between actual physiological (mainly visceral) events and their perceived counterparts is substantial. On the one hand, we typically do not perceive actual visceral events occurring in our bodies; on the other hand, sometimes we do perceive bodily changes that do not really take place. This narrative review presents the available empirical findings on the discordance, and summarizes possible explanations that approach the phenomenon from the viewpoint of evolution, cognitive development, and predictive processing. Also, the role of top-down factors, such as expectations and experiences is discussed. Finally, practically relevant consequences of the discordance are presented using the examples of mind-body practices, the placebo and nocebo phenomenon, and medically unexplained symptoms. It is concluded that the discordance between actual and perceived body changes can have a negative impact on health, mainly through issues with adherence and other behavioral factors. The existence of actual-perceived discordance should be taught and demonstrated in the elementary and high school, as well as in many areas of higher education.

[Interoceptive difficulties in children and adolescents with severe form of somatic symptom disorder: A pilot study with nineteen participants]

INTRODUCTION

Despite the high rate of somatic symptom disorder (TSS) in the pediatric population, etiological mechanisms remain poorly understood. Previous studies conducted in youths with anxiety, eating disorder, or autistic disorder support a relation between difficulties in the perception of sensory signals (i.e., interoception) and difficulties in identifying emotions.

METHOD

A cross-sectional study was carried out at the University Hospital of Amiens-Picardie in 19 young people aged 9 to 17 hospitalized in the pediatric ward for TSS. A mental heartbeat tracking task was used to assess interoceptive accuracy, awareness and sensibility. The Porges Body Perception Questionnaire (PBPQ) was used to assess interoceptive attention. Other questionnaires were used to assess associated clinical dimensions such as depression, anxiety, emotional dysregulation and alexithymia.

RESULTS

The mean interoceptive accuracy score was lower in TSS subjects compared to expected scores in the general population (33% error vs. 20%). A statistically significant correlation was found between, on the one hand, interoceptive sensibility and the "avoidance" subscore of the ECAP (r=0.51) and, on the other hand, between interoceptive awareness and the total score of the Child Depression Inventory (r=0.51). A significant relationship was found between the PBPQ scale total score and the Children-Toronto Alexithymia Scale total score (r=0.42), in particular with the "difficulty expressing emotions" subscore (r=0.62).

CONCLUSION

This study confirms that interoceptive difficulties occur in young patients with severe TSS. Our finding adds empirical evidence supporting the relations between interoceptive difficulties, alexithymia and somatic symptoms in children and adolescents.

Rhesus monkeys have an interoceptive sense of their beating hearts

SignificanceThe capacity to sense interoceptive signals is thought to be fundamental to broad functions including, but not limited to, homeostasis and the experience of the self. While neuroanatomical evidence suggests that nonhuman animals-namely, nonhuman primates-may possess features necessary for interoceptive processing in a way that is similar to humans, behavioral evidence of this capacity is slim. We presented macaques with audiovisual stimuli that were either synchronous or asynchronous with their heartbeat and demonstrated that they view asynchronous stimuli, whether faster or slower, for a significantly longer period than they do synchronous stimuli.

A heartbeat away from a valid tracking task. An empirical comparison of the mental and the motor tracking task

Individuals' ability to perceive their heartbeats, called cardioceptive accuracy, is assessed with various paradigms. Performance in the mental and a novel motor tracking task that eliminates disturbing tactile sensations was assessed at rest and during walking with the participation of 45 young people. Significantly higher scores in the mental tracking task than in the motor tracking task were found. Scores obtained at rest were consistently higher than their walking counterparts. Motor responses showed no temporal association with heartbeats for 84% of participants at rest and 95% during walking. Overall, participants' cardioceptive accuracy at rest and under slight physical activity was poor. Even if people rely on their heartbeat-related sensations during their daily activity, it is either not the ability that is assessed by the tracking tasks, or it is a relatively poor source of information about the actual state of the body.

Mental heartbeat tracking and rating of emotional pictures are not related

Our aim was to conceptually replicate the findings of previous empirical studies showing that people with higher cardiac interoceptive accuracy experience more intense emotions. Apart of the mental heartbeat tracking task of Schandry, Hungarian (n = 46, 76.0% female, mean age 22.28 ± 2.228) and Norwegian (n = 50, 60.0% female, mean age 24.66 ± 3.048) participants rated the arousal and valence evoked by positive, neutral and negative pictures. Multivariate repeated analysis of variance (applying both frequentist and Bayesian approaches) did not reveal any connection between heartbeat perception scores and the subjective ratings (i.e., arousal and valence) of the pictures in any of the two groups. The lack of the expected association between cardioceptive accuracy and arousal might partly be explained by the methodological differences between previous studies and this one; for example, we did not split or preselected the sample based on the performance on the Schandry task and applied a relatively strict instruction (i.e., by encouraging to count felt heartbeats only, and to report zero if no sensations were detected).

The effect of aerobic exercise on interoception and cognitive function in healthy university students: a non-randomized controlled trial

BACKGROUND

Interoception refers to the body's physiological responses that occur in response to emotions. This phenomenon influences decision-making, an important cognitive ability that affects the maintenance of an exercise routine. However, it is controversial whether interoception is a reliable measure of an individual's traits or their response to emotion. Given this evidence, we hypothesized that performing an exercise with positive feelings could improve interoception and that the rational decision-making capabilities acquired by improved interoception would, in turn, help in maintaining an exercise routine. Persistent aerobic exercise is essential for improving cognitive and musculoskeletal function in the long term. Therefore, we aimed to investigate changes in interoception during moderate-intensity aerobic exercise at a level that might potentially improve cognitive function.

METHODS

We devided 48 healthy university students into an exercise group (n = 37) and a control group (n = 11). The control group did not perform any exercises, while the exercise group performed bench step exercises at an intensity of 50% of heart rate reserve for 30 min a day, three times a week, for three months. We assessed their cognitive function by measuring their auditory information/working memory processing speed using a paced auditory serial addition task (PASAT) and evaluated their interoceptive accuracy (IA) using a heartbeat tracking task at baseline and 1, 2, and 3 months after the start of the exercise intervention.

RESULTS

There was a significant positive correlation between IA and PASAT scores at baseline. However, exercise did not lead to a significant increase in PASAT scores of the exercise group as compared with the control group. IA scores increased at 2 and 3 months after the start of exercise only in the exercise group.

CONCLUSIONS

This preliminary study showed an improvement in interoception after persistent moderate-intensity aerobic exercise. We believe that exercise-induced improvement of interoception may facilitate exercise maintenance through improved cognitive function. Statistical analysis did not explain the non-uniformity of sample sizes, therefore, future studies should have larger sample sizes with equal subjects in each group to allow for better comparability and generalizability.

TRIAL REGISTRATION

UMIN, UMIN000042891. 04/01/2021, retrospectively registered.

On the construct validity of interoceptive accuracy based on heartbeat counting: Cardiovascular determinants of absolute and tilt-induced change scores

Interoceptive accuracy (IAcc) as assessed with the heartbeat counting task (IAcc_HBCT) may be affected by a range of factors including (1.) the ability to adequately detect cardiac signals, indicated by IAcc in a heartbeat discrimination task (IAcc_HBDT), (2.) cardiac signal properties, affected by sympathetic and parasympathetic tone, and (3.) non-interoceptive processes, including time estimation accuracy (TEAcc). In the current study we investigated the contribution of these factors to absolute and Δ IAcc_HBCT scores, induced by passive head-up and head-down tilt in 49 healthy individuals. A set of hierarchical regression models showed IAcc_HBDT scores as the strongest and, across different orthostatic (tilt) conditions, most stable (positive) predictor of absolute and Δ IAcc_HBCT scores. Neither indicators of cardiac signal properties (except for HR in head-down-tilt), nor TEAcc predicted absolute or Δ IAcc_HBCT scores. These findings support the convergent and discriminant validity of absolute and Δ IAcc_HBCT scores.

Perceptual insensitivity to the modulation of interoceptive signals in depression, anxiety, and substance use disorders

This study employed a series of heartbeat perception tasks to assess the hypothesis that cardiac interoceptive processing in individuals with depression/anxiety (N = 221), and substance use disorders (N = 136) is less flexible than that of healthy individuals (N = 53) in the context of physiological perturbation. Cardiac interoception was assessed via heartbeat tapping when: (1) guessing was allowed; (2) guessing was not allowed; and (3) experiencing an interoceptive perturbation (inspiratory breath hold) expected to amplify cardiac sensation. Healthy participants showed performance improvements across the three conditions, whereas those with depression/anxiety and/or substance use disorder showed minimal improvement. Machine learning analyses suggested that individual differences in these improvements were negatively related to anxiety sensitivity, but explained relatively little variance in performance. These results reveal a perceptual insensitivity to the modulation of interoceptive signals that was evident across several common psychiatric disorders, suggesting that interoceptive deficits in the realm of psychopathology manifest most prominently during states of homeostatic perturbation.

Learning to make smart choices in the context of risk: The roles of internal affective feedback and life events

Autonomic arousal may facilitate beneficial decision-making when the link between choices and outcomes is uncertain. However, it is unknown whether greater risk-specific autonomic arousal is linearly associated with faster learning to avoid risky decisions. Furthermore, although the influence of stress on decision-making is well documented, it is unknown whether recent life stress might moderate the relationship between this internal affective feedback and decision-making. We report two studies using the Iowa Gambling Task with diverse community samples. Each study demonstrated a linear relationship between the level of autonomic arousal prior to risky decision-making and the rate of learning to avoid risk. Additionally, participants' recent life events conditionally moderated this association. Specifically, the relationship between risk-specific arousal and advantageous learning was strongest for participants who experienced relatively more positive and fewer negative life events in the previous four months. These findings suggest that autonomic arousal may generally inform decision-making, but less so when life circumstances are relatively poor.

Interoception, Stress, and Physical Symptoms in Stress-Associated Diseases

Abstract. The brain and peripheral bodily organs continuously exchange information. Exemplary, interoception refers to the processing and perception of ascending information from the body to the brain. Stress responses involve a neurobehavioral cascade, which includes the activation of peripheral organs via neural and endocrine pathways and can thus be seen as an example for descending information on the brain-body axis. Hence, the interaction of interoception and stress represents bi-directional communication on the brain-body axis. The main hypothesis underlying this review is that the dysregulation of brain-body communication represents an important mechanism for the generation of physical symptoms in stress-related disorders. The aims of this review are, therefore, (1) to summarize current knowledge on acute stress effects on different stages of interoceptive signal processing, (2) to discuss possible patterns of abnormal brain-body communication (i.e., alterations in interoception and physiological stress axes activation) in mental disorders and chronic physical conditions, and (3) to consider possible approaches to modify interoception. Due to the regulatory feedback loops underlying brain-body communication, the modification of interoceptive processes (ascending signals) may, in turn, affect physiological stress axes activity (descending signals), and, ultimately, also physical symptoms.

Proprioception but not cardiac interoception is related to the rubber hand illusion

The rubber hand illusion (RHI) is a widely used tool in the study of multisensory integration. It develops as the interaction of temporally consistent visual and tactile input, which can overwrite proprioceptive information. Theoretically, the accuracy of proprioception may influence the proneness to the RHI but this has received little research attention to date. Concerning the role of cardioceptive information, the available empirical evidence is equivocal. The current study aimed to test the impact of proprioceptive and cardioceptive input on the RHI. 60 undergraduate students (32 females) completed sensory tasks assessing proprioceptive accuracy with respect to the angle of the elbow joint, a heartbeat tracking task assessing cardioceptive accuracy (the Schandry-task) and the RHI. We found that those with more consistent joint position judgements (i.e., less variable error) in the proprioceptive task were less prone to the illusion, particularly with respect to disembodiment ratings in the asynchronous condition. Systematic error, indicating a systematic distortion in position judgements influenced the illusion in the synchronous condition. Participants with more proprioceptive bias toward the direction of the rubber hand in the proprioceptive test reported a stronger felt embodiment. The results are in accordance with Bayesian causal inference models of multisensory integration. Cardioceptive accuracy, however, was not associated with the strength of the illusion. We concluded that individual differences in proprioceptive processing impact the RHI, while cardioceptive accuracy is unrelated to it. Theoretical and practical relevance of the findings are discussed.

A multidimensional and multi-feature framework for cardiac interoception

Interoception (the sensing of inner-body signals) is a multi-faceted construct with major relevance for basic and clinical neuroscience research. However, the neurocognitive signatures of this domain (cutting across behavioral, electrophysiological, and fMRI connectivity levels) are rarely reported in convergent or systematic fashion. Additionally, various controversies in the field might reflect the caveats of standard interoceptive accuracy (IA) indexes, mainly based on heartbeat detection (HBD) tasks. Here we profit from a novel IA index (md) to provide a convergent multidimensional and multi-feature approach to cardiac interoception. We found that outcomes from our IA-md index are associated with -and predicted by- canonical markers of interoception, including the hd-EEG-derived heart-evoked potential (HEP), fMRI functional connectivity within interoceptive hubs (insular, somatosensory, and frontal networks), and socio-emotional skills. Importantly, these associations proved more robust than those involving current IA indexes. Furthermore, this pattern of results persisted when taking into consideration confounding variables (gender, age, years of education, and executive functioning). This work has relevant theoretical and clinical implications concerning the characterization of cardiac interoception and its assessment in heterogeneous samples, such as those composed of neuropsychiatric patients.

Altered Function of Superior Parietal Lobule Associated with Perceptive Awareness in First-Episode Drug-Naïve Panic Disorders: A Preliminary fMRI Study

BACKGROUND

Biased fear-related perception is one main characteristic in patients with panic disorder (PD) and their prominent cardiovascular symptoms associated with enhanced heartbeat perception.

PATIENTS AND METHODS

We investigated interoceptive perception in 18 first-onset drug-naïve PD patients and 21 age- and gender-matched healthy controls (HC). Moreover, we compared blood oxygen level-dependent (BOLD) responses between the two groups during a heartbeat perception (interoception) task to assess task-evoked activity and its relationship with heartbeat perception scores (HPSs).

RESULTS

We found that patients with PD compared to HCs revealed a trend higher but insignificant HPSs. Higher activity in the bilateral superior parietal lobule (SPL) was observed in PD patients compared to HCs during the perception of both heartbeats and pure tones compared to rest. Furthermore, patients with PD exhibited a significant positive correlation between BOLD activity in the left SPL during heartbeat > resting-state and HPS.

CONCLUSION

Using a sample of first-episode drug-naïve patients, our study reports that patients with PD show altered activation in the bilateral SPL during both interoceptive and exteroceptive perception. The increased activation during interoceptive stimuli might render PD patients more engaged in processing information associated with their internal states.

Mindfulness, Interoception, and the Body: A Contemporary Perspective

Mindfulness is often used as an umbrella term to characterize a large number of practices, processes, and characteristics. Critics argue that this broad definition has led to misinformation, misunderstanding, and a general lack of methodologically rigorous research. Some of the confusion surrounding mindfulness is also believed to stem from an undifferentiated use of the term mindfulness and meditation. Mindfulness and all other forms of meditation have been shown to modulate the insula, which is the primary hub for interoception. Some have argued that interoception is foundational to mindfulness and may be the primary mechanism by which one benefits from the practice. However, much like the mindfulness literature, interoception remains broadly defined often without precision and with domain-specific meanings and implications. Research demonstrates that the insula and surrounding neural circuits are believed to be responsible for a number of other functions beyond interoception including attention, awareness, and all subjective experiences, much of which has been linked to the mindfulness literature. It has been assumed that mindfulness produces these neuroplasticity and functional effects. There is evidence that mindfulness and some of its benefits may be better described as increased interoception as a result of the neuroplasticity changes in the insula, and the development of the insula and surrounding neural circuits may cultivate dispositional mindfulness. The purposes of this article are to (1) highlight that it may be more accurate to link many of the identified benefits in the mindfulness literature to interoception and its neurological correlates and (2) propose attentional style as a means to clarify some of the confusion surrounding mindfulness, interoception, and meditation. Different meditations require different attentional styles. Attention can be analogous to a focal point with each focal point providing a unique perspective. Given that all meditative techniques modulate the insula, each meditation can provide a unique perspective from which to investigate complex interoceptive signals that may be unavailable from other meditative traditions. It may prove more useful to anchor scientific findings in the concrete body as a means to investigate those rather than a set of abstract, broadly defined meditative techniques.

Common and different neural markers in major depression and anxiety disorders: A pilot structural magnetic resonance imaging study

Although anxiety and depression often co-occur and share some clinical features, it is still unclear if they are neurobiologically distinct or similar processes. In this study, we explored common and specific cortical morphology alterations in depression and anxiety disorders. Magnetic Resonance Imaging data were acquired from 13 Major Depressive Disorder (MDD), 11 Generalized Anxiety Disorder (GAD), 11 Panic Disorder (PD) patients and 21 healthy controls (HC). Regional cortical thickness, surface area (SA), volume and gyrification were measured and compared among groups. We found left orbitofrontal thinning in all patient groups, as well as disease-specific alterations. MDD showed volume deficits in left precentral gyrus compared to all groups, volume and area deficits in right fusiform gyrus compared to GAD and HC. GAD showed lower SA than MDD and PD in right superior parietal cortex, higher gyrification than HC in right frontal gyrus. PD showed higher gyrification in left superior parietal cortex when compared to MDD and higher SA in left postcentral gyrus compared to all groups. Our results suggest that clinical phenotypic similarities between major depression and anxiety disorders might rely on common prefrontal alterations. Frontotemporal and parietal abnormalities may represent unique biological signatures of depression and anxiety.

Interoceptive deficits in patients with obsessive-compulsive disorder in the time course of cognitive-behavioral therapy

Interoception is impaired in different psychiatric disorders and is also associated with emotions. Only one study could show a higher interoceptive accuracy (IAcc) in patients with obsessive-compulsive disorder (OCD). Based on the predictive coding system we assume contrary results, indicating a decreased IAcc in patients with OCD. So far, there is no study investigating the effect of cognitive-behavioral therapy on IAcc in patients with OCD. Therefore, we hypothesize that patients with OCD improve their IAcc during the time course of therapy compared to healthy controls. Twenty-six patients with OCD from the Psychosomatic Clinic in Windach were examined in the time course of cognitive-behavioral therapy. They were compared to 26 matched healthy controls. IAcc via the heartbeat perception task as well as questionnaire data (OCD-, depression- and anxiety symptoms) were assessed. Results showed that IAcc, OCD-, depression- and anxiety symptoms were attenuated in patients with OCD. Patients recovered in the time course of therapy regarding OCD-, depression- and anxiety symptoms. Interoceptive deficits did not change in the time course of cognitive-behavioral therapy. We demonstrated that IAcc is affected in patients with OCD and this deficit does not change during the time course of a standardized therapy. Future studies should investigate, whether an inaccuracy in perceiving one's bodily signals constitutes a risk factor for relapse. Further, it could be examined if IAcc can be increased via self- and body focus interventions in patients with OCD.

Interoception: the forgotten modality in perceptual grounding of abstract and concrete concepts

Conceptual representations are perceptually grounded, but when investigating which perceptual modalities are involved, researchers have typically restricted their consideration to vision, touch, hearing, taste and smell. However, there is another major modality of perceptual information that is distinct from these traditional five senses; that is, interoception, or sensations inside the body. In this paper, we use megastudy data (modality-specific ratings of perceptual strength for over 32 000 words) to explore how interoceptive information contributes to the perceptual grounding of abstract and concrete concepts. We report how interoceptive strength captures a distinct form of perceptual experience across the abstract-concrete spectrum, but is markedly more important to abstract concepts (e.g. hungry, serenity) than to concrete concepts (e.g. capacity, rainy). In particular, interoception dominates emotion concepts, especially negative emotions relating to fear and sadness, moreso than other concepts of equivalent abstractness and valence. Finally, we examine whether interoceptive strength represents valuable information in conceptual content by investigating its role in concreteness effects in word recognition, and find that it enhances semantic facilitation over and above the traditional five sensory modalities. Overall, these findings suggest that interoception has comparable status to other modalities in contributing to the perceptual grounding of abstract and concrete concepts.This article is part of the theme issue 'Varieties of abstract concepts: development, use and representation in the brain'.

A latent state-trait analysis of interoceptive accuracy

Interoceptive accuracy (IAc), that is, the ability to accurately perceive one's own bodily signals, is widely assumed to be a trait, although experimental manipulations such as stress may affect IAc. We used structural equation modeling to estimate the reliability of IAc, and the proportions of individual differences in IAc, explained by a trait and occasion-specific effects of situation and person-situation interactions. We assessed IAc in 59 healthy participants (40 women, M_Age  = 23.4 years) on three consecutive measurement occasions, approximately 1 week apart, in a rest and poststress condition, using a heartbeat counting and a heartbeat discrimination task. The results showed fair temporal stability (intraclass correlation coefficients ≥ 0.38) and good reliability (Mdn = .63; range .49-.83) for both methods. While around 40% of the variance of a single IAc measurement could be explained by a trait, approximately 27% was accounted for by occasion-specific effects of situation and person-situation interaction. These results suggest that IAc measures are relatively consistent and that situations and person-situation interactions impact IAc as measured at a certain point in time. An aggregation across at least two measurements is recommended when using IAc as a trait variable.

Oxytocin Modulates Attention Switching Between Interoceptive Signals and External Social Cues

Emotional experience involves an integrated interplay between processing of external emotional cues and interoceptive feedback, and this is impaired in a number of emotional disorders. The neuropeptide oxytocin (OT) enhances the salience of external social cues but its influence on interoception is unknown. The present pharmaco-fMRI study therefore investigated whether OT enhances interoceptive awareness and if it influences the interplay between interoceptive and salience processing. In a randomized, double-blind, between-subject, design study 83 subjects received either intranasal OT or placebo. In Experiment 1, subjects performed a heartbeat detection task alone, while in Experiment 2 they did so while viewing both neutral and emotional face stimuli. Interoceptive accuracy and neural responses in interoceptive and salience networks were measured. In Experiment 1, OT had no significant influence on interoceptive accuracy or associated activity in the right anterior insula (AI) and dorsal anterior cingulate cortex. However, in Experiment 2 when face stimuli were also presented, OT decreased interoceptive accuracy and increased right AI activation and its functional connectivity with the left posterior insula (PI), with the latter both being negatively correlated with accuracy scores. The present study provides the first evidence that while OT does not influence processing of interoceptive cues per se it may switch attention away from them towards external salient social cues by enhancing right AI responses and its control over the PI. Thus OT may help regulate the interplay between interoceptive and external salience processing within the insula and could be of potential therapeutic benefit for emotional disorders.

Improvement of Interoceptive Processes after an 8-Week Body Scan Intervention

Objective: Interoceptive processes are defined as ability to detect sensations arising within the body. There is a growing body of research investigating ways of improving interoceptive processes. One promising approach increasing the attention to bodily sensations is the body scan (BS), a method stemming from mindfulness-based stress reduction. Research so far revealed only heterogenous findings of meditational practice and mindfulness-based stress reduction on interoceptive processes. Even more importantly, there is no study considering the effect of an 8-week BS intervention on interoceptive processes and the distinguishable subdomains of interoception. Therefore, the main objective of this research is to examine the effects of a BS intervention on different interoceptive subdomains over 8 weeks of training in two different samples.

Methods: In study 1, healthy participants executed a 20 min standardized audiotaped BS in the BS intervention group (n = 25) each day over 8 weeks. The control group (n = 24) listened to an audio book for the same amount of time. In study 2, the BS group (n = 18) was compared to an inactive control group (n = 18). In both studies, three measurement points were realized and interoceptive accuracy (IAc) – using a heartbeat perception task – as well as interoceptive sensibility (IS) – using confidence ratings for the heartbeat perception task and the subscale ‘interoceptive awareness’ of the Eating Disorder Inventory-2 (EDI-2) – were assessed.

Results: In study 1, we found, as a descriptive trend, IAc and confidence ratings to be increased irrespective of the condition. However, post hoc analysis revealed a significant improvement of IAc between T1 and T3 in the BS intervention only. IS revealed to be unaffected by the interventions. In study 2, we observed a significant positive effect of the BS intervention on IAc and confidence ratings compared to the inactive controls. As in study 1, IS (EDI-2) was unaffected by the intervention.

Discussion: The results highlight the fact that interoception can be improved by long-term interventions focusing on bodily signals. Further studies might focus on clinical samples showing deficits in interoceptive processes and could use other bodily systems for measurement (e.g., respiratory signals) as well methods manipulating body ownership.

Social Power Increases Interoceptive Accuracy

Building on recent psychological research showing that power increases self-focused attention, we propose that having power increases accuracy in perception of bodily signals, a phenomenon known as interoceptive accuracy. Consistent with our proposition, participants in a high-power experimental condition outperformed those in the control and low-power conditions in the Schandry heartbeat-detection task. We demonstrate that the effect of power on interoceptive accuracy is not explained by participants’ physiological arousal, affective state, or general intention for accuracy. Rather, consistent with our reasoning that experiencing power shifts attentional resources inward, we show that the effect of power on interoceptive accuracy is dependent on individuals’ chronic tendency to focus on their internal sensations. Moreover, we demonstrate that individuals’ chronic sense of power also predicts interoceptive accuracy similar to, and independent of, how their situationally induced feeling of power does. We therefore provide further support on the relation between power and enhanced perception of bodily signals. Our findings offer a novel perspective–a psychophysiological account–on how power might affect judgments and behavior. We highlight and discuss some of these intriguing possibilities for future research.

Panic Disorder Comorbidity with Medical Conditions and Treatment Implications

Panic disorder (PD) is unique among the anxiety disorders in that panic symptoms are primarily of a physical nature. Consequently, comorbidity with medical illness is significant. This review examines the association between PD and medical illness. We identify shared pathophysiological and psychological correlates and illustrate how physiological activation in panic sufferers underlies their symptom experience in the context of the fight-or-flight response and beyond a situation-specific response pattern. We then review evidence for bodily symptom perception accuracy in PD. Prevalence of comorbidity for PD and medical illness is presented, with a focus on respiratory and cardiovascular illness, irritable bowel syndrome, and diabetes, followed by an outline for potential pathways of a bidirectional association. We conclude by illustrating commonalities in mediating mechanistic pathways and moderating risk factors across medical illnesses, and we discuss implications for diagnosis and treatment of both types of conditions.

Generalized hypervigilance in fibromyalgia: Normal interoceptive accuracy, but reduced self-regulatory capacity

OBJECTIVE

The factors underlying the aetiology of fibromyalgia (FM) are largely unknown. According to the generalized hypervigilance hypothesis (GHH), FM patients show excessive attention towards pain stimuli and other sensory events, thereby increasing pain perception and dysfunctional behaviour. We tested this notion by assessing interoceptive accuracy (IA) in FM patients and matched healthy controls. We also tested the hypothesis that FM is characterized by reduced self-regulatory capacity as indexed by heart rate variability (HRV).

METHODS

47 FM patients (M_age=45.5, 39 females) and 45 healthy controls (M_age=44.9, 37 females) completed several self-report scales (Body Vigilance Scale, Depression Anxiety Stress Scales, Pain Catastrophizing Scale). To derive HRV, heart rate was monitored under resting conditions; for the assessment of IA participants performed a heartbeat tracking task in which they were asked to silently count their heartbeats.

RESULTS

FM patients reported higher body vigilance than healthy controls, but there were no group differences in IA. FM patients had lower HRV compared with healthy controls. HRV did not predictor IA.

CONCLUSION

In conclusion, our findings do not support the hypothesis of generalized hypervigilance in FM patients. Patients reported a heightened focus on bodily sensations, which was not reflected in IA. It may be that hypervigilance is not a general and stable characteristic but is rather context dependent and modality-specific.

The contribution of trait negative affect and stress to recall for bodily states

How does trait negative affect shape somatic memory of stressful events? We hypothesized that negative affect would impair accurate recall of one's own heart rate during stressful situations. Two bio-behavioral studies used a new paradigm to test retrospective visceral perception and assessed whether negative affective states experienced during aversive events (i.e., the Trier Stress Task-Time 1) would retrospectively shape recall of past heart rate (Time 2), even when accounting for actual heart rate at the time of each stressful event (Time 1). Results across both studies showed that individual differences in negative affect in response to a stressful task predicted visceral recollections, and those who experienced more negative affect were more inaccurate. Negative affect was associated with a tendency to remember visceral reactions as worse than they actually were.

Mechanisms of mindfulness training: Monitor and Acceptance Theory (MAT)

Despite evidence linking trait mindfulness and mindfulness training with a broad range of effects, still little is known about its underlying active mechanisms. Mindfulness is commonly defined as (1) the ongoing monitoring of present-moment experience (2) with an orientation of acceptance. Building on conceptual, clinical, and empirical work, we describe a testable theoretical account to help explain mindfulness effects on cognition, affect, stress, and health outcomes. Specifically, Monitor and Acceptance Theory (MAT) posits that (1), by enhancing awareness of one's experiences, the skill of attention monitoring explains how mindfulness improves cognitive functioning outcomes, yet this same skill can increase affective reactivity. Second (2), by modifying one's relation to monitored experience, acceptance is necessary for reducing affective reactivity, such that attention monitoring and acceptance skills together explain how mindfulness improves negative affectivity, stress, and stress-related health outcomes. We discuss how MAT contributes to mindfulness science, suggest plausible alternatives to the account, and offer specific predictions for future research.

Neural correlates of heart-focused interoception: a functional magnetic resonance imaging meta-analysis

Interoception is the ability to perceive one's internal body state including visceral sensations. Heart-focused interoception has received particular attention, in part due to a readily available task for behavioural assessment, but also due to accumulating evidence for a significant role in emotional experience, decision-making and clinical disorders such as anxiety and depression. Improved understanding of the underlying neural correlates is important to promote development of anatomical-functional models and suitable intervention strategies. In the present meta-analysis, nine studies reporting neural activity associated with interoceptive attentiveness (i.e. focused attention to a particular interoceptive signal for a given time interval) to one's heartbeat were submitted to a multilevel kernel density analysis. The findings corroborated an extended network associated with heart-focused interoceptive attentiveness including the posterior right and left insula, right claustrum, precentral gyrus and medial frontal gyrus. Right-hemispheric dominance emphasizes non-verbal information processing with the posterior insula presumably serving as the major gateway for cardioception. Prefrontal neural activity may reflect both top-down attention deployment and processing of feed-forward cardioceptive information, possibly orchestrated via the claustrum.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

Interoceptive dimensions across cardiac and respiratory axes

Interoception refers to the sensing of signals concerning the internal state of the body. Individual differences in interoceptive sensitivity are proposed to account for differences in affective processing, including the expression of anxiety. The majority of investigations of interoceptive accuracy focus on cardiac signals, typically using heartbeat detection tests and self-report measures. Consequently, little is known about how different organ-specific axes of interoception relate to each other or to symptoms of anxiety. Here, we compare interoception for cardiac and respiratory signals. We demonstrate a dissociation between cardiac and respiratory measures of interoceptive accuracy (i.e. task performance), yet a positive relationship between cardiac and respiratory measures of interoceptive awareness (i.e. metacognitive insight into own interoceptive ability). Neither interoceptive accuracy nor metacognitive awareness for cardiac and respiratory measures was related to touch acuity, an exteroceptive sense. Specific measures of interoception were found to be predictive of anxiety symptoms. Poor respiratory accuracy was associated with heightened anxiety score, while good metacognitive awareness for cardiac interoception was associated with reduced anxiety. These findings highlight that detection accuracies across different sensory modalities are dissociable and future work can better delineate their relationship to affective and cognitive constructs.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

Interaction effect of brooding rumination and interoceptive awareness on depression and anxiety symptoms

Awareness of the body (i.e., interoceptive awareness) and self-referential thought represent two distinct, yet habitually integrated aspects of self. A recent neuroanatomical and processing model for depression and anxiety incorporates the connections between increased but low fidelity afferent interoceptive input with self-referential and belief-based states. A deeper understanding of how self-referential processes are integrated with interoceptive processes may ultimately aid in our understanding of altered, maladaptive views of the self - a shared experience of individuals with mood and anxiety disorders. Thus, the purpose of the current study was to examine how negative self-referential processing (i.e., brooding rumination) relates to interoception in the context of affective psychopathology. Undergraduate students (N = 82) completed an interoception task (heartbeat counting) in addition to self-reported measures of rumination and depression and anxiety symptoms. Results indicated an interaction effect of brooding rumination and interoceptive awareness on depression and anxiety-related distress. Specifically, high levels of brooding rumination coupled with low levels of interoceptive awareness were associated with the highest levels of depression and anxiety-related distress, whereas low levels of brooding rumination coupled with high levels of interoceptive awareness were associated with lower levels of depression and anxiety-related distress. The findings provide further support for the conceptualization of anxiety and depression as conditions involving the integration of interoceptive processes and negative self-referential processes.

Clinical neurocardiology defining the value of neuroscience-based cardiovascular therapeutics

The autonomic nervous system regulates all aspects of normal cardiac function, and is recognized to play a critical role in the pathophysiology of many cardiovascular diseases. As such, the value of neuroscience-based cardiovascular therapeutics is increasingly evident. This White Paper reviews the current state of understanding of human cardiac neuroanatomy, neurophysiology, pathophysiology in specific disease conditions, autonomic testing, risk stratification, and neuromodulatory strategies to mitigate the progression of cardiovascular diseases.

Effects of Mindfulness-Based Cognitive Therapy on Body Awareness in Patients with Chronic Pain and Comorbid Depression

Body awareness has been proposed as one of the major mechanisms of mindfulness interventions, and it has been shown that chronic pain and depression are associated with decreased levels of body awareness. We investigated the effect of Mindfulness-Based Cognitive Therapy (MBCT) on body awareness in patients with chronic pain and comorbid active depression compared to treatment as usual (TAU; N = 31). Body awareness was measured by a subset of the Multidimensional Assessment of Interoceptive Awareness (MAIA) scales deemed most relevant for the population. These included: Noticing, Not-Distracting, Attention Regulation, Emotional Awareness, and Self-Regulation. In addition, pain catastrophizing was measured by the Pain Catastrophizing Scale (PCS). These scales had adequate to high internal consistency in the current sample. Depression severity was measured by the Quick Inventory of Depressive Symptomatology—Clinician rated (QIDS-C₁₆). Increases in the MBCT group were significantly greater than in the TAU group on the “Self-Regulation” and “Not Distracting” scales. Furthermore, the positive effect of MBCT on depression severity was mediated by “Not Distracting.” These findings provide preliminary evidence that a mindfulness-based intervention may increase facets of body awareness as assessed with the MAIA in a population of pain patients with depression. Furthermore, they are consistent with a long hypothesized mechanism for mindfulness and emphasize the clinical relevance of body awareness.

Interoceptive awareness changes the posterior insula functional connectivity profile

Interoceptive awareness describes the ability to consciously perceive inner bodily signals, such as one's own heartbeat. The right anterior insula is assumed to mediate this ability. The role of the posterior insula, particularly posterior-to-anterior insula signal flows is less clear in this respect. We scanned 27 healthy people with either high or low interoceptive awareness using 3T fMRI, while they either monitored their own heartbeats, or external tones, respectively. We used a combination of network centrality and bivariate connectivity analyses to characterize changes in cortical signal flows between the posterior insula and the anterior insula during interoceptive awareness or exteroceptive awareness, respectively. We show that heartbeat monitoring was accompanied by reduced network centrality of the right posterior insula, and decreased functional connectivity strengths between the right posterior insula and the right mid and anterior insula. In addition, decreased signal flows between the right posterior insula and the bilateral anterior cingulate cortices, and the bilateral orbitofrontal cortices were observed during interoceptive awareness. Functional connectivity changes were only shown by people with high interoceptive awareness, and occurred specifically within the low-frequency range (i.e., <0.1 Hz). Both groups did not differ in their functional connectivity profiles during rest. Our results show for the first time that interoceptive awareness changes intra-insula signal flows in the low-frequency range. We speculate that the selective inhibition of slow signal progression along the posterior-to-anterior insula pathway during interoceptive awareness allows the salient and noiseless detection of one's own heartbeat.

The Relationship Between Interoception and Metacognition

Abstract. Recently, Garfinkel and Critchley (2013) proposed to distinguish between three facets of interoception: interoceptive sensibility, interoceptive accuracy, and interoceptive awareness. This pilot study investigated how these facets interrelate to each other and whether interoceptive awareness is related to the metacognitive awareness of memory performance. A sample of 24 healthy students completed a heartbeat perception task (HPT) and a memory task. Judgments of confidence were requested for each task. Participants filled in questionnaires assessing interoceptive sensibility, depression, anxiety, and socio-demographic characteristics. The three facets of interoception were found to be uncorrelated and interoceptive awareness was not related to metacognitive awareness of memory performance. Whereas memory performance was significantly related to metamemory awareness, interoceptive accuracy (HPT) and interoceptive awareness were not correlated. Results suggest that future research on interoception should assess all facets of interoception in order to capture the multifaceted quality of the construct.

Can Interoception Improve the Pragmatic Search for Biomarkers in Psychiatry?

Disrupted interoception is a prominent feature of the diagnostic classification of several psychiatric disorders. However, progress in understanding the interoceptive basis of these disorders has been incremental, and the application of interoception in clinical treatment is currently limited to panic disorder. To examine the degree to which the scientific community has recognized interoception as a construct of interest, we identified and individually screened all articles published in the English language on interoception and associated root terms in Pubmed, Psychinfo, and ISI Web of Knowledge. This search revealed that interoception is a multifaceted process that is being increasingly studied within the fields of psychiatry, psychology, neuroscience, and biomedical science. To illustrate the multifaceted nature of interoception, we provide a focused review of one of the most commonly studied interoceptive channels, the cardiovascular system, and give a detailed comparison of the most popular methods used to study cardiac interoception. We subsequently review evidence of interoceptive dysfunction in panic disorder, depression, somatic symptom disorders, anorexia nervosa, and bulimia nervosa. For each disorder, we suggest how interoceptive predictions constructed by the brain may erroneously bias individuals to express key symptoms and behaviors, and outline questions that are suitable for the development of neuroscience-based mental health interventions. We conclude that interoception represents a viable avenue for clinical and translational research in psychiatry, with a well-established conceptual framework, a neural basis, measurable biomarkers, interdisciplinary appeal, and transdiagnostic targets for understanding and improving mental health outcomes.

Altered interoceptive awareness in anorexia nervosa: Effects of meal anticipation, consumption and bodily arousal

OBJECTIVE

Impaired interoceptive awareness (IA), the subjective perception of internal body sensations, has been proposed as a vulnerability or maintaining factor in anorexia nervosa (AN). We examined whether IA of heartbeat and breathing sensations was impaired in AN across a range of arousal levels, and whether it was influenced by meal anticipation and consumption.

METHOD

IA was assessed using randomized, double-blinded, bolus intravenous infusions of isoproterenol, a peripheral beta-adrenergic sympathetic agonist, and saline. Fifteen women with AN and 15 age-, and sex- matched healthy comparisons (HC) were evaluated before and after consumption of a 1,000 Calorie meal. During each infusion participants rated their moment-to-moment intensity of heartbeat and breathing sensations with a dial. To measure IA we evaluated interoceptive detection thresholds, retrospective ratings of palpitation and dyspnea intensity, and interoceptive accuracy via correlations between subjective dial ratings and observed heart rate responses.

RESULTS

Contrary to prediction the AN group was more likely to report detection of interoceptive sensations across all conditions, an effect driven by false discriminations at low arousal levels. Concordant with prediction, meal anticipation was associated with intensified interoceptive sensations, particularly dyspnea. There were no differences in interoceptive accuracy.

DISCUSSION

This represents the first demonstration of interoceptive prediction errors in AN. Although IA is unimpaired at high arousal levels in AN, prediction signals are abnormal at low arousal levels, especially during meal anticipation. Altered interoceptive prediction signaling during meal anticipation could contribute to phenotypes of high anxiety in AN or alternatively, might be explained by enhanced meal associated anxiety.

Interoception and stress

Afferent neural signals are continuously transmitted from visceral organs to the brain. Interoception refers to the processing of visceral-afferent neural signals by the central nervous system, which can finally result in the conscious perception of bodily processes. Interoception can, therefore, be described as a prominent example of information processing on the ascending branch of the brain–body axis. Stress responses involve a complex neuro-behavioral cascade, which is elicited when the organism is confronted with a potentially harmful stimulus. As this stress cascade comprises a range of neural and endocrine pathways, stress can be conceptualized as a communication process on the descending branch of the brain–body axis. Interoception and stress are, therefore, associated via the bi-directional transmission of information on the brain–body axis. It could be argued that excessive and/or enduring activation (e.g., by acute or chronic stress) of neural circuits, which are responsible for successful communication on the brain–body axis, induces malfunction and dysregulation of these information processes. As a consequence, interoceptive signal processing may be altered, resulting in physical symptoms contributing to the development and/or maintenance of body-related mental disorders, which are associated with stress. In the current paper, we summarize findings on psychobiological processes underlying acute and chronic stress and their interaction with interoception. While focusing on the role of the physiological stress axes (hypothalamic-pituitary-adrenocortical axis and autonomic nervous system), psychological factors in acute and chronic stress are also discussed. We propose a positive feedback model involving stress (in particular early life or chronic stress, as well as major adverse events), the dysregulation of physiological stress axes, altered perception of bodily sensations, and the generation of physical symptoms, which may in turn facilitate stress.

Dimensional structure of bodily panic attack symptoms and their specific connections to panic cognitions, anxiety sensitivity and claustrophobic fears

BACKGROUND

Previous studies of the dimensional structure of panic attack symptoms have mostly identified a respiratory and a vestibular/mixed somatic dimension. Evidence for additional dimensions such as a cardiac dimension and the allocation of several of the panic attack symptom criteria is less consistent. Clarifying the dimensional structure of the panic attack symptoms should help to specify the relationship of potential risk factors like anxiety sensitivity and fear of suffocation to the experience of panic attacks and the development of panic disorder.

METHOD

In an outpatient multicentre study 350 panic patients with agoraphobia rated the intensity of each of the ten DSM-IV bodily symptoms during a typical panic attack. The factor structure of these data was investigated with nonlinear confirmatory factor analysis (CFA). The identified bodily symptom dimensions were related to panic cognitions, anxiety sensitivity and fear of suffocation by means of nonlinear structural equation modelling (SEM).

RESULTS

CFA indicated a respiratory, a vestibular/mixed somatic and a cardiac dimension of the bodily symptom criteria. These three factors were differentially associated with specific panic cognitions, different anxiety sensitivity facets and suffocation fear.

CONCLUSIONS

Taking into account the dimensional structure of panic attack symptoms may help to increase the specificity of the associations between the experience of panic attack symptoms and various panic related constructs.

The roles of interoceptive sensitivity and metacognitive interoception in panic

BACKGROUND

Interoception refers to the ability to sense body signals. Two interoceptive dimensions have been recently proposed: (a) interoceptive sensitivity (IS) -objective accuracy in detecting internal bodily sensations (e.g., heartbeat, breathing)-; and (b) metacognitive interoception (MI) -explicit beliefs and worries about one's own interoceptive sensitivity and internal sensations. Current models of panic assume a possible influence of interoception on the development of panic attacks. Hypervigilance to body symptoms is one of the most characteristic manifestations of panic disorders. Some explanations propose that patients have abnormal IS, whereas other accounts suggest that misinterpretations or catastrophic beliefs play a pivotal role in the development of their psychopathology. Our goal was to evaluate these theoretical proposals by examining whether patients differed from controls in IS, MI, or both. Twenty-one anxiety disorders patients with panic attacks and 13 healthy controls completed a behavioral measure of IS motor heartbeat detection (HBD) and two questionnaires measuring MI.

FINDINGS

Patients did not differ from controls in IS. However, significant differences were found in MI measures. Patients presented increased worries in their beliefs about somatic sensations compared to controls. These results reflect a discrepancy between direct body sensing (IS) and reflexive thoughts about body states (MI).

CONCLUSION

Our findings support the idea that hypervigilance to body symptoms is not necessarily a bottom-up dispositional tendency (where patients are hypersensitive about bodily signals), but rather a metacognitive process related to threatening beliefs about body/somatic sensations.

Interoceptive ability and body awareness in autism spectrum disorder

Autism spectrum disorder (ASD) has been associated with various sensory atypicalities across multiple domains. Interoception, the ability to detect and attend to internal bodily sensations, has been found to moderate the experience of body ownership, a known difference in ASD that may affect social function. However, interoception has not been empirically examined in ASD. In the current study, 45 children (21 with ASD and 24 controls) ages 8 to 17 years completed a heartbeat perception paradigm as a measure of interoceptive ability. A subset of these children also completed the rubber hand illusion task, a multisensory paradigm probing the malleability of perceived body ownership. Although the heartbeat perception paradigm yielded comparable interoceptive awareness (IA) overall across both groups, children with ASD were superior at mentally tracking their heartbeats over longer intervals, suggesting increased sustained attention to internal cues in ASD. In addition, IA was negatively correlated with rubber hand illusion susceptibility in both groups, supporting a previously demonstrated inverse relationship between internal awareness and one's ability to incorporate external stimuli into one's perception of self. We propose a trade-off between attention to internal cues and attention to external cues, whereby attentional resources are disproportionately allocated to internal, rather than external, sensory cues in ASD.

Interoceptive sensitivity, body image dissatisfaction, and body awareness in healthy individuals

Relationships among interoceptive sensitivity (IS), body image dissatisfaction, body mass index (BMI), and self-reported body awareness were investigated in a cross-sectional study. Eighty-two Norwegian high school students and 70 Hungarian undergraduate university students participated in the study. Subjects completed two questionnaires (Body Image Ideals Questionnaire - BIQ; Body Awareness Questionnaire - BAQ) followed by the assessment of interoceptive sensitivity using the Mental Tracking Method (MTM). An inverse, medium-level relationship between body image dissatisfaction and IS was found in both the Norwegian and the Hungarian samples. The relationships between IS and self-reported body awareness, and between body image dissatisfaction and BMI were uniformly non-significant in both samples. Predictors of body image dissatisfaction were resting heart rate, gender, and IS in the regression analysis after controlling for BMI, age, and nationality. The negative relationship between IS and body image dissatisfaction described in patients with anorexia nervosa also exists in healthy individuals. There is no direct connection between IS and self-reported body awareness.