Blood, sweat, and tears: individual differences in autonomic self-perception

Heart activity perception: narrative review on the measures of the cardiac perceptual ability

Measures of cardiac perceptual ability (also called cardiac accuracy) are methods of cardiac interoception, the perception of bodily sensation related to heart activity. This narrative review aims to provide an overview of these methods. We differentiate between three main measurement types: (1) change detection, i.e., when the task is to notice the change in the heart rate; also called: heart rate perception tasks, (2) discrimination tasks, i.e., when the task is to compare the internal sensations with external signal(s); also called: heartbeat detection tasks and (3) tracking tasks, i.e., when the task is to follow and report heartbeats via tapping or counting. We describe some of the new methods under "mixed methods," as they share features with more than one of the large measurement types described above. Specific measures differ in various aspects, such as their focus (heart rhythm vs. single beats), their sensitivity to non-conscious sensations and the calculated indices (e.g., whether significance level by hypothesis test is provided). When a measure of cardiac perceptual ability is chosen, it is advisable to take its characteristics into consideration in light of the planned research.

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 accuracy does not predict emotion perception in daily life

Peripheral emotion theories suggest a crucial role of interoception for emotion perception, which in turn facilitates emotion regulation. Laboratory studies found positive relations between interoceptive accuracy and perceived emotion intensity and arousal. Studies in natural settings are largely missing, but seem important by virtue of emotional experience and regulation diversity.

On hundred seven participants underwent a cardiovascular interoceptive accuracy task. Afterwards, participants provided detailed information on perceived emotions and emotion regulation strategies in an ecological momentary assessment (EMA). Multilevel models were calculated. In consideration of valence, emotion intensity, arousal, intensity of body sensations and, emotion regulation success were modeled as a function of centered interoceptive accuracy.

Interoceptive accuracy did not predict any emotion perception criterion. Lower accuracy was related to a slightly stronger decrease of perceived arousal after regulation.

Differences in emotion categories, intensity, and sample collection might explain divergences to laboratory studies.

Sex differences in interoceptive accuracy: A meta-analysis

Interoceptive accuracy, the ability to correctly perceive internal signals arising from the body, is thought to be disrupted in numerous mental and physical health conditions. Whilst evidence suggests poorer interoceptive accuracy in females compared to males, raising the possibility that interoceptive differences may relate to sex differences in mental and physical health, results concerning sex differences in interoceptive accuracy are mixed. Given such ambiguity, this meta-analysis aimed to establish the presence or absence of sex differences in interoceptive accuracy across cardiac, respiratory, and gastric domains. A review of 7956 abstracts resulted in 93 eligible studies. Results demonstrated superior accuracy in males across cardiac, but not gastric, tasks, while findings on respiratory tasks were mixed. Effect sizes were consistent across cardiac tasks, but instability and/or moderate heterogeneity was observed across other domains, likely due to the small number of eligible studies. Despite such limitations, results indicate the possibility of sex differences across interoception tasks and domains. Methodological limitations concerning the influence of physiological factors, and directions for future research are discussed.

Interoception in preschoolers: New insights into its assessment and relations to emotion regulation and stress

Interoception may play an important role for emotion regulation and stress, thereby affecting mental health in children and adults. Yet, little is known on interoception in preschool children. Therefore, we investigated interoceptive accuracy using the adapted Jumping Jack Paradigm (JJP) and its relationship with emotion regulation and stress. In Study I, 40 preschoolers completed the JJP and an emotion regulation task, demonstrating a positive relationship between interoceptive accuracy and emotion regulation at trend level (R² = 0.231, p = .023; β = .278, p = .073). In Study II, 31 preschoolers completed the adapted JJP before and after an acute laboratory stress test. Higher total cortisol output following acute stress induction was associated with reduced interoceptive accuracy (r = -0.670, p = .017). Extending earlier findings in adults and school-children, the relationship of interoceptive accuracy with emotion regulation and stress highlights the importance to investigate interoception in early childhood.

Expectation predicts performance in the mental heartbeat tracking task

The mental heartbeat tracking task by Schandry is sensitive to non-interoceptive (top-down) influences, e.g., estimation of heart rate and expectation. The two studies reported here investigated the impact of these factors on the outcome of the task. In Study 1, performance-related expectation was assessed between the training interval and the real trials. Performance was strongly related (β = .595, p < .001) to expectation even after controlling for sex, body fat, resting heart rate and estimation of heart rate. In Study 2, expectation was assessed before and after the training interval for Group 1 and 2, respectively. The strong association (r = 0.78, p < .001) between performance and expectation was replicated for Group 2; however, a moderate association (r = 0.39, p < .01) was also found in Group 1. People with high expectation may be prone to categorize and count vague sensations, such as attention evoked sensations, as heartbeats; this can lead to an inflated Schandry-score.

Behavioral and neurophysiological signatures of interoceptive enhancements following vagus nerve stimulation

An accruing body of research has shown that interoception (the sensing of signals from the body's internal milieu) relies on both a direct route (afforded by the vagus nerve) and a secondary route (supported by somatosensory mechanisms). However, no study has causally tested the differential role of these pathways, let alone via direct stimulation. To bridge this gap, we tested whether multidimensional signatures of interoception are modulated by noninvasive vagus nerve stimulation (nVNS). Sixty-three participants were divided into an nVNS and a sham-stimulation group. Before and after stimulation, both groups performed a validated heartbeat detection (HBD) task including a genuinely interoceptive condition (monitoring one's own heartbeat) and a control exteroceptive condition (tracking an aurally presented heartbeat). Electroencephalographic signals were obtained during both conditions to examine modulations of the heartbeat-evoked potential (HEP). Moreover, before and after stimulation, participants were asked to complete a somatosensory heartbeat localization task. Results from the interoceptive condition revealed that, after treatment, only the nVNS group exhibited improved performance and greater HEP modulations. No behavioral differences were found for the exteroceptive control condition, which was nonetheless associated with significant HEP modulations. Finally, no between-group differences were observed regarding the localization of the heartbeat sensations or relevant cardiodynamic variables (heart rate and or heart rate variability). Taken together, these results constitute unprecedented evidence that the vagus nerve plays a direct role in neurovisceral integration during interoception. This finding can constrain mechanistic models of the domain while informing a promising transdiagnostic agenda for interoceptive impairments across neuropsychiatric conditions.

Interaction Between Sex and Cardiac Interoceptive Accuracy in Measures of Induced Pain

Pain perception is influenced by several factors, and among them, affect, sex, and perception of bodily signals are assumed to play a prominent role. The aim of the present study is to explore how sex, cardiac interoceptive accuracy, and the interaction of the latter two influence the perception of experimentally induced pain. We investigated a large sample of young adults (n = 159, 50.9% female, age: 23.45, SD = 3.767), assessing current positive and negative affective state with the Positive and Negative Affect Schedule (both involved as control variables), cardiac interoceptive accuracy with the mental heartbeat tracking task, and pain sensitivity with electrical stimulation on the back of the dominant hand, applying a repeated-measures staircase protocol. Males showed a significantly higher pain threshold and tolerance level than females, whereas cardiac interoceptive accuracy was not associated with pain sensitivity. The impact of sex × cardiac interoceptive accuracy interaction was significant for pain threshold only, while pain tolerance was predicted only by sex. According to these findings, the associations between pain sensitivity, cardiac IAc, and sex might be more complicated than it was supposed in previous studies. Interactions between factors impacting pain perception appear worthy of further investigation.

Understanding the capture of exogenous attention by disgusting and fearful stimuli: The role of interoceptive accuracy

The aim of the study was to explore the role of interoceptive accuracy (IA) on exogenous attention to disgusting and fearful distractors of a main concurrent task. Participants were thirty university students previously identified as high (N = 16) or normal IA according their performance in a heartbeat detection task. Event-related potentials and behavioural responses were recorded. The results showed that disgusting stimuli capture exogenous attention in a first stage as reflected by the augmented amplitude of the P100 component of the ERPs in high IA participants. Fearful distractors may capture attention in a later moment in all participants as revealed by a marginally significant effect on the amplitude of N200. At behavioural level, disgusting distractors provoked a higher number of errors than neutral in normal IA participants. The time course of the effect of disgust and fearful eliciting distractors on exogenous attention appeared to depend on the individual characteristic of participants.

Cardiac cycle phases affect auditory-evoked potentials, startle eye blink and pre-motor reaction times in response to acoustic startle stimuli

Startle stimuli evoke lower responses when presented during the early as compared to the late cardiac cycle phase, an effect that has been called 'cardiac modulation of startle' (CMS). The CMS effect may be associated with visceral-afferent neural traffic, as it is reduced in individuals with degeneration of afferent autonomic nerves. The aim of this study was to investigate whether the CMS effect is due a modulation of only early, automatic stages of stimulus processing by baro-afferent neural traffic, or if late stages are also affected. We, therefore, investigated early and late components of auditory-evoked potentials (AEPs) to acoustic startle stimuli (105, 100, 95 dB), which were presented during the early (R-wave +230 ms) or the late cardiac cycle phase (R +530 ms) in two studies. In Study 1, participants were requested to ignore (n = 25) or to respond to the stimuli with button-presses (n = 24). In Study 2 (n = 23), participants were asked to rate the intensity of the stimuli. We found lower EMG startle response magnitudes (both studies) and slower pre-motor reaction times in the early as compared to the late cardiac cycle phase (Study 1). We also observed lower N1 negativity (both studies), but higher P2 (Study 1) and P3 positivity (both studies) in response to stimuli presented in the early cardiac cycle phase. This AEP modulation pattern appears to be specific to the CMS effect, suggesting that early stages of startle stimulus processing are attenuated, whereas late stages are enhanced by baro-afferent neural traffic.

The effects of alcohol on heartbeat perception: Implications for anxiety

INTRODUCTION

It is well established that some individuals self-medicate their anxiety with alcohol. Though much evidence exists that alcohol consumption can be negatively reinforcing, there remains uncertainty regarding what mediates the relationship between alcohol and anxiety. An unexplored possibility is that, for some, alcohol impairs interoceptive sensitivity (the ability to accurately perceive one's physiological state), thereby decreasing state anxiety. Consistent with this, highly accurate heartbeat perception is a risk factor both for elevated trait anxiety and anxiety disorders. However, the direct impact of alcohol on cardioceptive accuracy has not to our knowledge been previously examined.

METHODS

Sixty-one social drinkers came to the lab in groups of 4-6 on two days spaced a week apart. Each participant was randomly assigned to receive alcoholic drinks targeting a BAC of 0.05% on one testing day and placebo drinks on the other, with the order counter-balanced. On both testing days, participants engaged in a Schandry heartbeat perception task on three occasions: at baseline, after an alcohol absorption period, and after physiological arousal was raised via exercise.

RESULTS

For men only, alcohol significantly impaired cardioceptive accuracy relative to a placebo at both low and high levels of arousal, with medium to large effect sizes.

CONCLUSIONS

Though preliminary, this finding is consistent with the proposed hypothesis linking alcohol consumption and anxiety, at least for men. Future studies should directly examine whether, among individuals with anxiety disorders, cardioceptive sensitivity mediates the relationship between alcohol consumption and state anxiety.

Zur Anwendung der Signalentdeckungstheorie bei der Auswertung von Aufgaben zur motorischen Verfolgung der eigenen Herzschläge

Zusammenfassung. Aufgaben zur Entdeckung und Verfolgung der eigenen Herzschläge werden standardmäßig als ein Maß für eine umfassendere interozeptive Fähigkeit eingesetzt. Bei der Auswertung dieser Aufgaben wird aber nur selten ein echtes Maß für die Sensitivität der Wahrnehmung körpereigener Signale verwendet. Die vorliegende Studie hat sich deshalb dieser Fragestellung angenommen und die Daten einer sogenannten Herzschlagentdeckungsaufgabe (HBDT) mithilfe der Signalentdeckungstheorie (SDT) ausgewertet. Die Ergebnisse (N = 44) zeigen entsprechend, dass der so gewonnene Sensitivitätsindex (d’) deutlich unabhängiger von der reinen Anzahl der in einer motorischen HBDT abgegebenen Reaktionen ist, als herkömmliche Maße der Herzschlagentdeckungsfähigkeit. Mit d’ kann somit eine vielfach kritisierte Konfundierung bei den herkömmlichen Maßen aufgelöst und dadurch die Validität der HBDT erhöht werden. Darüber hinaus konnte, wie schon wiederholt mit einem herkömmlichen Accuracy-Maß gezeigt, auch mit unserem SDT-Index d’ ein Trainingseffekt der interozeptiven Fähigkeit nachgewiesen werden. Ferner ist an dieser Studie innovativ, dass zur Feststellung der tatsächlichen Herztätigkeit erstmalig die Doppler-Sonographie eingesetzt wurde.

Further Evidence for an External Focus of Attention in Running: Looking at Specific Focus Instructions and Individual Differences

Although attentional focusing in sports has been broadly investigated, the findings vary when it comes to endurance sports. This study provides a comparison between relevant foci in the literature of running economy. These include two internal foci-one addressing automated processes (running movement) and the other nonautomated processes (internal body signals and perceived exertion), an external focus (video) and a control condition. Furthermore, we investigated the influence of interoceptive sensitivity on oxygen consumption within the different attention conditions. Thirty recreational runners performed a four 6-min run at moderate intensity consisting of the four counterbalanced conditions. Running economy was assessed by spiroergometry, and interoception was measured using a heartbeat tracking task. Results revealed a significantly better running economy for the external focus of attention compared with all other conditions. No significant correlations were observed between the heartbeat perception score and oxygen consumption in any condition.

Body Awareness and Yoga Training

This study was done to investigate whether the practice of hatha yoga enhances the awareness of the normal, nonemotive bodily processes. A yoga-trained group of 17 and a control group of 19 were administered the Body Awareness Questionnaire. Analysis showed that the yoga-trained group had a significantly better body awareness than the control group.

Heart Rate Variability (HRV) Analysis: A Methodology for Organizational Neuroscience

Recently, the application of neuroscience methods and findings to the study of organizational phenomena has gained significant interest and converged in the emerging field of organizational neuroscience. Yet, this body of research has principally focused on the brain, often overlooking fuller analysis of the activities of the human nervous system and associated methods available to assess them. In this article, we aim to narrow this gap by reviewing heart rate variability (HRV) analysis, which is that set of methods assessing beat-to-beat changes in the heart rhythm over time, used to draw inference on the outflow of the autonomic nervous system (ANS). In addition to anatomo-physiological and detailed methodological considerations, we discuss related theoretical, ethical, and practical implications. Overall, we argue that this methodology offers the opportunity not only to inform on a wealth of constructs relevant for management inquiries but also to advance the overarching organizational neuroscience research agenda and its ecological validity.

Objectification Theory: Toward Understanding Women's Lived Experiences and Mental Health Risks

This article offers objectification theory as a framework for understanding the experiential consequences of being female in a culture that sexually objectifies the female body. Objectification theory posits that girls and women are typically acculturated to internalize an observer's perspective as a primary view of their physical selves. This perspective on self can lead to habitual body monitoring, which, in turn, can increase women's opportunities for shame and anxiety, reduce opportunities for peak motivational states, and diminish awareness of internal bodily states. Accumulations of such experiences may help account for an array of mental health risks that disproportionately affect women: unipolar depression, sexual dysfunction, and eating disorders. Objectification theory also illuminates why changes in these mental health risks appear to occur in step with life-course changes in the female body.

Links among emotional awareness, somatic awareness and autonomic homeostatic processing

Emotional awareness and somatic interoceptive awareness are essential processes for human psychosomatic health. A typical trait of lacking emotional awareness related to psychosomatic symptoms is alexithymia. In contrast, alexisomia refers to the trait of lacking somatic awareness. Links between emotional and somatic awareness and homeostatic processing are also significant for the psychosomatic health. The purpose of the present paper is to review the links among emotional awareness, somatic interoceptive awareness and autonomic homeostatic processing. On the basis of the collected evidence, the following arguments were presented¹: (1) The main subcortical neural substrates for these processes are limbic-related systems, which are also responsible for autonomic functions for optimization of homeostatic efficiency. (2) Considerable studies have shown that autonomic activity and/or reactivity to stress correlate with both emotional and interoceptive awareness. A hypothesis was advocated about the links between the two types of awareness and autonomic function: Autonomic dysfunction, especially high sympathetic tone at baseline and/or attenuated reactivity or variability to stress, appears to be involved in disturbance of emotional and interoceptive awareness. (3) Several studies suggest that a link or a cooperative relationship exists between emotional and somatic awareness, and that somatic awareness is the more fundamental of the two types of awareness. Emotional awareness, somatic awareness and autonomic homeostatic processing generally occur in parallel or concurrently. However, some complex features of pathologies include coexistence of reduced interoceptive awareness and somatosensory amplification. The autonomic homeostatic process is fundamentally involved in emotional and somatic awareness. Investigation of these types of awareness with both neuroimaging evaluations and estimation of peripheral autonomic function are required as next steps for exploration of the relationship between awareness and human somatic states including somatic symptoms as well as general psychosomatic health.

Discovering your inner Gibson: reconciling action-specific and ecological approaches to perception-action

Both the action-specific perception account and the ecological approach to perception-action emphasize the role of action in perception. However, the action-specific perception account demonstrates that different percepts are possible depending on the perceiver's ability to act, even when the same optical information is available. These findings challenge one of the fundamental claims of the ecological approach--that perception is direct--by suggesting that perception is mediated by internal processes. Here, we sought to resolve this apparent discrepancy. We contend that perception is based on the controlled detection of the information available in a global array that includes higher-order patterns defined across interoceptive and exteroceptive stimulus arrays. These higher-order patterns specify the environment in relation to the perceiver, so direct sensitivity to them would be consistent with the ecological claims that perception of the environment is direct and animal-specific. In addition, the action-specific approach provides further evidence for the theory of affordances, by demonstrating that even seemingly abstract properties of the environment, such as distance and size, are ultimately perceived in terms of an agent's action capabilities.

Neural Circuitry of Interoception: New Insights into Anxiety and Obsessive-Compulsive Disorders

Over the past century, much research has investigated how the brain processes signals from the body (interoception) and how this processing may be disturbed in patients with psychiatric disorders. In this paper, I discuss the literature examining the relationship between interoceptive awareness and emotional and cognitive processes, and review the evidence suggesting that anxiety and obsessive-compulsive disorder (OCD) are characterized by abnormal interoception. A network of cortical and subcortical brain regions centered on the insula has repeatedly been implicated in interoception and is abnormal in anxiety and OCD. The investigation of interoception provides a framework for understanding behavioral and neural mechanisms of anxiety and OCD, although additional research is needed to directly link insula functioning to aberrant interoception in these disorders. Future work targeting interoception may be useful for the development of novel treatments.

Biofeedback-based training for stress management in daily hassles: an intervention study

BACKGROUND

The day-to-day causes of stress are called daily hassles. Daily hassles are correlated with ill health. Biofeedback (BF) is one of the tools used for acquiring stress-coping skills. However, the anatomical correlates of the effects of BF with long training periods remain unclear. In this study, we aimed to investigate this.

METHODS

PARTICIPANTS WERE ASSIGNED RANDOMLY TO TWO GROUPS: the intervention group and the control group. Participants in the intervention group performed a biofeedback training (BFT) task (a combination task for heart rate and cerebral blood flow control) every day, for about 5 min once a day. The study outcomes included MRI, psychological tests (e.g., Positive and Negative Affect Schedule, Center for Epidemiologic Studies Depression Scale, and Brief Job Stress Questionnaire), and a stress marker (salivary cortisol levels) before (day 0) and after (day 28) the intervention.

RESULTS

We observed significant improvements in the psychological test scores and salivary cortisol levels in the intervention group compared to the control group. Furthermore, voxel-based morphometric analysis revealed that compared to the control group, the intervention group had significantly increased regional gray matter (GM) volume in the right lateral orbitofrontal cortex, which is an anatomical cluster that includes mainly the left hippocampus, and the left subgenual anterior cingulate cortex. The GM regions are associated with the stress response, and, in general, these regions seem to be the most sensitive to the detrimental effects of stress.

CONCLUSIONS

Our findings suggest that our BFT is effective against the GM structures vulnerable to stress.

The impact of cardiac perception on emotion experience and cognitive performance under mental stress

Mental stress evokes several physiological responses such as the acceleration of heart rate, increase of electrodermal activity and the release of adrenaline. Moreover, physiological stress responses interact with emotional and behavioral stress responses. In the present study we provide evidence that viscero-sensory feedback from the heart (cardiac perception) is an important factor modulating emotional and cognitive stress responses. In our study, we compared participants with high versus low cardiac perception using a computerized mental stress task, in which they had to respond to rapidly presented visual and acoustic stimuli. Additionally, we assessed physiological responses (heart rate, skin conductance). Participants high in cardiac perception reported more negative emotions and showed worse task performance under the stressor than participants low in cardiac perception. These results were not moderated by physiological responses. We conclude that cardiac perception modulates stress responses by intensifying negative emotions and by impairing cognitive performance.

What the heart forgets: Cardiac timing influences memory for words and is modulated by metacognition and interoceptive sensitivity

Mental functions are influenced by states of physiological arousal. Afferent neural activity from arterial baroreceptors at systole conveys the strength and timing of individual heartbeats to the brain. We presented words under limited attentional resources time-locked to different phases of the cardiac cycle, to test a hypothesis that natural baroreceptor stimulation influences detection and subsequent memory of words. We show memory for words presented around systole was decreased relative to words at diastole. The deleterious memory effect of systole was greater for words detected with low confidence and amplified in individuals with low interoceptive sensitivity, as indexed using a heartbeat counting task. Our observations highlight an important cardiovascular channel through which autonomic arousal impacts a cognitive function, an effect mitigated by metacognition (perceptual confidence) and interoceptive sensitivity.

Interoceptive sensitivity in anxiety and anxiety disorders: an overview and integration of neurobiological findings

Interoceptive sensitivity, particularly regarding heartbeat, has been suggested to play a pivotal role in the pathogenesis of anxiety and anxiety disorders. This review provides an overview of methods which are frequently used to assess heartbeat perception in clinical studies and summarizes presently available results referring to interoceptive sensitivity with respect to heartbeat in anxiety-related traits (anxiety sensitivity, state/trait anxiety), panic disorder and other anxiety disorders. In addition, recent neurobiological studies of neuronal activation correlates of heartbeat perception using positron emission tomography (PET), functional magnetic resonance imaging (fMRI) or electroencephalographic (EEG) techniques are presented. Finally, possible clinical and therapeutic implications (e.g., beta-blockers, biofeedback therapy, cognitive interventions and interoceptive exposure) of the effects of heartbeat perception on anxiety and the anxiety disorders and the potential use of interoceptive sensitivity as an intermediate phenotype of anxiety disorders in future neurobiological and genetic studies are discussed.

The Relationship Between Pain Perception and Interoception

The question of whether the perception of externally applied pain stimuli and the perception of interoceptive stimuli are based upon similar neuronal or behavioral processes is still open to debate. If such a similarity exists, one would expect that persons who are highly sensitive to visceral stimuli would also exhibit a higher sensitivity to pain stimuli. The present study investigated the sensitivity to heat pain of individuals with high vs. low cardiac interoceptive sensitivity. Pain threshold and pain tolerance were assessed using a testing-the-limits procedure. Furthermore, participants rated the subjective intensity and unpleasantness of tonic heat stimuli on visual analog scales and in a questionnaire. The results show that pain experience did not differ between participants with high and low interoceptive sensitivity, nor did correlation analyses reveal significant relationships between pain experience and cardiac interoceptive sensitivity. These findings suggest that the pathway of peripheral pain processing is at least partially independent of the pathway of interoceptive sensations.

Alimentary Epigenetics: A Developmental Psychobiological Systems View of the Perception of Hunger, Thirst and Satiety

Hunger, thirst and satiety have an enormous influence on cognition, behavior and development, yet we often take for granted that they are simply inborn or innate. Converging data and theory from both comparative and human domains, however, supports the conclusion that the phenomena hunger, thirst and satiety are not innate but rather emerge probabilistically as a function of experience during individual development. The metatheoretical perspective provided by developmental psychobiological systems theory provides a useful framework for organizing and synthesizing findings related to the development of the perception of hunger, thirst and satiety, or alimentary interoception. It is argued that neither developmental psychology nor the psychology of eating and drinking have adequately dealt with the ontogeny of alimentary interoception and that a more serious consideration of the species-typical developmental system of food and fluid intake and the many modifications that have been made therein is likely necessary for a full understanding of both alimentary and emotional development.

Interozeptive Sensitivität, Gefühle und Verhaltensregulation

Die zentralnervöse Verarbeitung afferenter Signale aus dem Körperinneren ist nicht nur bei der basalen Kontrolle homöostatischer Prozesse im Körper zur Regulation fundamentaler Adaptationsprozesse des Organismus relevant, sondern spielt zusammen mit der bewussten Perzeptionsgenauigkeit dieser körperlichen Signale („interozeptive Sensitivität“) auch bei der Regulation komplexer kognitiver, emotionaler und behavioraler Prozesse eine nicht zu unterschätzende Rolle. Diese Übersichtsarbeit stellt theoretische Grundlagen zur interozeptiven Sensitivität dar und gibt einen Überblick über aktuelle empirische Forschungsergebnisse.

Functional magnetic resonance imaging analysis of attention to one's heartbeat

OBJECTIVES

The convergence of a neural system for monitoring external stimuli with mechanisms that process somatic information leads to the hypothesis that the anterior parietal cortex may mediate attention to a specific internal visceral signal.

METHODS

We measured regional brain activity through functional magnetic resonance imaging and directed subjects (6 men and 11 women) to attend to their own heartbeat, and to a heartbeat played on an external tape.

RESULTS

Statistical parametric brain mapping revealed the importance of right (nondominant) parietal cortex to directing attention internally to one's visceral state and focusing on a specific body signal.

CONCLUSIONS

The parietal activation may be taking advantage of monitoring skills typically utilized for vigilance to the external environment, in addition to working as a higher-level recognition system for signals emerging from the viscera. The finding suggests that the parietal cortex plays a central role in an interoceptive attention system that monitors bodily states.

Interoceptive sensitivity and emotion processing: An EEG study

Theories of emotion consider the self-perception of visceral activity to play an important role in emotion. This study examined the relationship between interoceptive sensitivity and both the subjective emotional experience and the processing of emotional pictures. According to their results in a heartbeat detection task subjects were classified as good (N = 17) or poor (N = 20) heartbeat perceivers. Event-related potentials were recorded while subjects viewed pleasant, neutral and unpleasant pictures and SAM ratings were examined. Good heartbeat perceivers showed significantly greater P300 and slow wave amplitudes for emotional pictures at antero-inferior, medial and posterior electrode sites and experienced a greater arousal for emotional pictures compared to poor heartbeat perceivers. The heartbeat perception score correlated significantly positive both with emotional P300 and slow wave amplitudes as well as with the arousal ratings for emotional pictures. The results indicate that there is a significant and strong association between interoceptive sensitivity and the intensity of emotional experience as well as the central processing of emotional stimuli.

Interoceptive sensitivity and physical effort: Implications for the self-control of physical load in everyday life

This study examined the relationship between interoceptive sensitivity and the behavioral self-regulation of physical load. According to their performance in a heartbeat detection task, 34 participants were classified as good or poor heartbeat perceivers. Participants pedaled on a bicycle ergometer for 15 min and were free to choose the tempo of their cycling. Good heartbeat perceivers covered a significantly shorter distance and showed a significantly smaller increase in mean heart rate, stroke volume, and cardiac output. There were significant negative correlations between heartbeat perception score and covered distance, changes in heart rate, changes in stroke volume, and changes in cardiac output. These results were not explained by differences in physical fitness level (PWC150). The findings suggest that good heartbeat perceivers show a more finely tuned behavioral self-regulation of physical load than poor heartbeat perceivers.

The association between anxiety and chronic pain after whiplash injury: gender-specific effects

OBJECTIVE

There is increasing evidence to suggest that anxiety is related more strongly to chronic pain experience in men relative to women. The aim of the present study was to examine for the first time gender-specific associations between anxiety and chronic pain experience in men and women exposed to whiplash trauma.

METHOD

One thousand seven hundred and nine people with whiplash (1349 women, 360 men) belonging to the Danish Society for Polio, Traffic, and Accident Victims completed a battery of questionnaires measuring demographic, psychologic, and pain-related factors (including frequency of painful episodes, level of pain interference, number of anatomic regions in which pain was felt, and the level of general disability).

RESULTS

Anxiety was found to be positively related to the level of general disability to a significantly stronger magnitude in men compared with women. A trend difference in correlation magnitude was also found between men and women when comparing anxiety with pain frequency, with the magnitude of correlation being higher in men.

DISCUSSION

The stronger association between anxiety and symptoms of whiplash trauma in men compared with women may be due to gender differences in the attribution of anxiety-related autonomic arousal as symptoms of whiplash injury. Alternatively, anxiety may differentially affect the willingness of men and women to report pain and other health indices. Anxiety is an important factor in understanding gender differences in whiplash-related symptoms such as chronic pain and disability, and requires further investigation.

Interoception in emotional experience

PURPOSE OF REVIEW

Many theories of emotion have postulated a close relationship of the feedback of physiological changes and their perception with emotional experience. This paper reviews recent advances in theory and brain-imaging research on this topic of interoception and describes a hypothetical model of the potential mechanisms.

RECENT FINDINGS

Research from patients with spinal-cord injuries and pure autonomic failure suggests that emotion-related peripheral autonomic changes are not necessary for emotional experience. However, in support of a role for centrally integrated feedback from the whole body, imaging studies found that activations in areas commonly associated with interoception and emotion (anterior insula and anterior cingulate) were correlated with individual differences in interoception (heartbeat detection) and trait measures of emotion. Because recent theory distinguishes between two levels of emotional experience (phenomenology and awareness), this paper proposes a hypothetical model of the effects of interoception on phenomenology and awareness. This model classifies interoception into the central representation of feedback from the whole body, the perception of actual physiological changes as well as the perception of illusory changes.

SUMMARY

Consistent with recent theories of emotion, evidence from brain imaging supports the notion that centrally integrated feedback from the whole body plays a role in emotional experience. Because research on neural correlates of emotional experience is at an early stage, the hypothesized model of potential causal links between interoception and emotional experience might serve as a helpful guide to future research.

Interoceptive sensitivity and self-reports of emotional experience

People differ in the extent to which they emphasize feelings of activation or deactivation in their verbal reports of experienced emotion, termed arousal focus (AF). Two multimethod studies indicate that AF is linked to heightened interoceptive sensitivity (as measured by performance on a heartbeat detection task). People who were more sensitive to their heartbeats emphasized feelings of activation and deactivation when reporting their experiences of emotion over time more than did those who were less sensitive. This relationship was not accounted for by several other variables, including simple language effects. Implications for the role of interoception in experienced emotion and the validity of self-reported emotion are discussed.

Facilitation of heartbeat self-perception in a discrimination task with individual adjustment of the S+ delay values

Thirty-two subjects (16 women, 16 men) performed two tasks that were the result of adapting the heartbeat perception tasks produced by Whitehead et al. [Biofeedback Self-Regul. 2 (1977) 371] and Katkin et al. [Psychophysiology 19 (1982) 568], respectively. In the Whitehead task, the delay values were the standard 128 ms for the S+ stimulus and 384 ms for the S- stimulus after the R-wave in one case; in the other case, the delay values were individually adjusted according to the median of the distribution of interval choices in an adaptation of the Brener and Kluvitse [Psychophysiology 25 (1988a) 554; Psychophysiology 25 (1988b) 436] task carried out previously. In the Katkin procedure, in one case S+ always occurred at a fixed interval (100 ms), whereas S- occurred at uniformly increasing intervals in relation to the R-wave. In the other case, the S+ and S- intervals were also individually modified according to the performance in the Brener and Kluvitse task. The results indicate that when the S+ values are individually adjusted, the sensitivity of subjects, as reflected in the 2(arcsin(p(A)(1/2))) values, significantly improves in the Whitehead task. Additionally, it was seen that the performance deteriorated from the first to the last 50 trials, especially when the S+ values were adjusted.

Effects of trial order and differential conditioning on acquisition of differential shock expectancy and skin conductance conditioning to masked stimuli

Research suggests that when people are fear conditioned to masked spiders and snakes (electric shocks are contingent on only spiders or snakes), they acquire a conditional skin conductance response and can predict the occurrence of shocks even though they are unable to identify the masked spiders and snakes. Because in prior studies trial order was not completely random, it is unclear if findings were due to the contingencies from differential conditioning or a restricted trial order or both. When participants were assigned to four groups to disentangle effects of trial order and differential conditioning to masked pictures in acquisition, effects were obtained only for trial order. These findings demonstrate that trial order can result in conditioning. However, because effects were observed even for participants who reported unawareness of the contingency from trial order, results are consistent with the notion of hunches or gut feelings.

Neuroendocrine responses to experimentally-induced emotions among abstinent opioid-dependent subjects

The present study investigated neuroendocrine and cardiovascular changes during experimentally-induced affective states in abstinent heroin-dependent subjects and healthy controls. The procedure for eliciting emotions in all subjects used pleasant and unpleasant stimuli that did not differ in subjective arousal properties. We investigated whether the valence of the stimuli differentially affected neuroendocrine responses by comparing neutral, pleasant and unpleasant pictures on heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), methyl-OH-phenyl-glycol (MHPG), norepinephrine (NE), epinephrine (EPI), adrenocorticotrophic hormone (ACTH) and cortisol (CORT) plasma levels. Twelve abstinent heroin-dependent subjects, in comparison with 12 control subjects, were submitted to three experimental sessions, each on one of three experimental days a week apart, in counterbalanced order: day 1=unpleasant pictures, day 2=pleasant pictures, day 3=neutral pictures. In the rating of subjective arousal pleasant and unpleasant stimuli received the same high score in comparison with neutral stimuli; a different cardiovascular and neuroendocrine pattern was obtained in healthy subjects: unpleasant stimuli elicited increases in HR, SBP, MHPG, NE, ACTH, CORT, whereas neutral and pleasant stimuli did not induce any significant response in hormonal levels. In contrast, in heroin addicts, despite increased perceptions of unpleasantness, HR, SBP, MHPG and NE levels did not increase after disliked stimuli; these subjects also reported increased arousal during exposure to neutral stimuli. In comparison with controls, addicted individuals showed higher CORT and ACTH basal levels, and a consequent lack of response to unpleasant stimuli. The results indicate that neuroendocrine and cardiovascular systems respond selectively to affective, motivationally relevant stimuli, and that substance use disorders may be associated with dysregulation of emotion-processing mechanisms.

Translating emotion theory and research into preventive interventions

Scientific advances in the field of emotions suggest a framework for conceptualizing the emotion-related aspects of prevention programs that aim to enhance children's socioemotional competence and prevent the emergence of behavior problems and psychopathology. A conception of emotions as inherently adaptive and motivational and the related empirical evidence from several disciplines and specialities suggest 7 principles for developing preventive interventions: the utilization of positive and negative emotions, emotion modulation as a mediator of emotion utilization, emotion patterns in states and traits, different processes of emotion activation, emotion communication in early life, and the development of connections for the modular and relatively independent emotions and cognitive systems. Each principle's practical implications and application in current prevention programs are discussed.