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Objective: Fear of hypoglycemia (FoH) is a limiting factor for diabetes self-management and can have detrimental effects on quality of life. However, relatively little is known about its underlying mechanisms. In line with findings on patients with anxiety disorders, we hypothesized that interoceptive accuracy (IA) might be positively linked to FoH in patients with type 2 diabetes (T2DM).Methods: 133 patients with T2DM were screened according to the extreme quartiles of the Hypoglycemia Fear Survey worry subscale (HFS-W). Overall, 66 participants (HFS-W<4; HFS-W>17) were included in the present study. Participants completed questionnaires on sociodemographic and diabetes-related measures. Accuracy of heartbeat perception was assessed using the mental tracking task.Results: Contrary to expectations, IA did not differ significantly between patients with low and high FoH. A linear regression analysis demonstrated that the experience of mild hypoglycemia (β=0.32, p≤0.01) and its interaction with IA (β=-0.26, p=0.040) were significant predictors of FoH, indicating that low IA and a history of experiencing mild hypoglycemia are positively associated with FoH.Conclusion: Our findings suggest a positive association of low IA in combination with prior episodes of hypoglycemia and FoH in patients with T2DM. The results are in line with recent findings on IA in patients with chronic somatic symptom distress more generally and contribute to our understanding of the relations between interoception, body related fears, and physical symptom perception. [ABSTRACT FROM AUTHOR]

Objective Various aspects of interoception are regarded as temporally stable phenomena. This study investigates the temporal stability of and longitudinal associations between interoceptive accuracy (as measured with heartbeat tracking task) and a related concept, body awareness (assessed by self-report). Methods In a two-month longitudinal study 103 university students (31% male, 23.34 ± 4.34 yrs.; 44 Hungarians; 36.4% male, 21.4 ± 1.67 yrs. and 59 Norwegians; 25.4% male, 24.8 ± 5.09 yrs) were investigated using Schandry's heartbeat tracking task and the Body Awareness Questionnaire. Results Both interoceptive accuracy and body awareness showed good test-retest reliability (r = 0.60 and r = 0.73, respectively; p < 0.001 in both cases). The two concepts were independent of each other at baseline (r = 0.06, p = 0.587), and did not predict each other over an eight weeks period of time. Conclusion Self-reported body awareness and objectively measured interoceptive accuracy are temporally stable and not related to each other. [ABSTRACT FROM AUTHOR]

Our judgements are often influenced by other people's views and opinions. Interoception also influences decision making, but little is known about its role in social influence and particularly, the extent to which other people may influence our decisions. Across two experiments, using different forms of social influence, participants judged the trustworthiness of faces presented either during the systolic phase of the cardiac cycle, when baroreceptors convey information from the heart to the brain, or during diastolic phase, when baroreceptors are quiescent. We quantified the extent to which participants changed their minds (as an index of social influence) following the social feedback, in order to compare two competing hypotheses. According to the Arousal-Confidence Hypothesis, cardiac signals create a context of heightened bodily arousal that increases confidence in perceptual judgements. People should, therefore, be less subject to social influence during systole. By contrast, according to the Uncertainty-Conformity Hypothesis, cardiac signals increase neural noise and sensory attenuation, such that people should display greater effects of social influence during systole, as they then underweight private interoceptive signals in favour of the external social information. Across two studies that used different kind of social interactions, we found that participants changed their minds more when faces were presented at systole. Our results, therefore, support the Uncertainly-Conformity hypothesis and highlight how cardiac afferent signals contribute to shape our social decision-making in different types of social interactions. [ABSTRACT FROM AUTHOR]

Interoception has been the subject of renewed interest over the past 2 decades. The involvement of interoception in a variety of fundamental human abilities (e.g., decision-making and emotional regulation) has led to the hypothesis that interoception is a central transdiagnostic process that causes and maintains mental disorders and physical diseases. However, interoception has been inconsistently defined and conceptualized. In the first part of this article, we argue that the widespread practice of defining interoception as the processing of signals originating from within the body and limiting it to specific physiological pathways (lamina I spinothalamic afferents) is problematic. This is because, in humans, the processing of internal states is underpinned by other physiological pathways generally assigned to the somatosensory system. In the second part, we explain that the consensual dimensions of interoception are empirically detached from existing measures, the latter of which capture loosely related phenomena. This is detrimental to the replicability of findings across measures and the validity of interpretations. In the general discussion, we discuss the main insights of the current analysis and suggest a more refined way to define interoception in humans and conceptualize its underlying dimensions. [ABSTRACT FROM AUTHOR]

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.

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.

The aim of this study is to investigate the bodily-self in Restrictive Anorexia, focusing on two basic aspects related to the bodily self: autonomic strategies in social behavior, in which others' social desirability features, and social cues (e.g., gaze) are modulated, and interoception (i.e., the sensitivity to stimuli originating inside the body). Furthermore, since previous studies carried out on healthy individuals found that interoception seems to contribute to the autonomic regulation of social behavior, as measured by Respiratory Sinus Arrhythmia (RSA), we aimed to explore this link in anorexia patients, whose ability to perceive their bodily signal seems to be impaired. To this purpose, we compared a group of anorexia patients (ANg; restrictive type) with a group of Healthy Controls (HCg) for RSA responses during both a resting state and a social proxemics task, for their explicit judgments of comfort in social distances during a behavioral proxemics task, and for their Interoceptive Accuracy (IA). The results showed that ANg displayed significantly lower social disposition and a flattened autonomic reactivity during the proxemics task, irrespective of the presence of others' socially desirable features or social cues. Moreover, unlike HCg, the autonomic arousal of ANg did not guide behavioral judgments of social distances. Finally, IA was strictly related to social disposition in both groups, but with opposite trends in ANg. We conclude that autonomic imbalance and its altered relationship with interoception might have a crucial role in anorexia disturbances.

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 D 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. [ABSTRACT FROM AUTHOR]

Interoception is the sense through which internal bodily changes are signalled and perceived. Individual differences in interoception are linked to emotional style and vulnerability to affective disorders. Here we test how experiential sleep quality relates to dimensions of interoceptive ability. 180 adults (42 ‘non-clinical’ individuals, 138 patients accessing mental health services) rated their quality of sleep before performing tests of cardiac interoception. Poor sleep quality was associated with lower measures of interoceptive performance accuracy, and higher self-report measures of interoceptive sensibility in individuals with diagnoses of depression and/or anxiety. Additionally, poor sleep quality was associated with impaired metacognitive interoceptive awareness in patients with diagnoses of depression (alone or with anxiety). Thus, poor sleep quality, a common early expression of psychological disorder, impacts cardiac interoceptive ability and experience across diagnoses. Sleep disruption can contribute to the expression of affective psychopathology through effects on perceptual and interpretative dimensions of bodily awareness. [ABSTRACT FROM AUTHOR]

Interoception, the sense of the physiological condition of the body originating from within its internal organs, and body image, namely the perception, feelings and attitudes one has about one’s body, are two fundamental components of our sense of personal identity and overall well-being. However, the relation between interoception and body image remains poorly understood. We here review recent behavioural and neuroimaging evidence from non-clinical and clinical populations (e.g. eating disorders) to propose that basic interoceptive processes and interoceptive awareness may crucially contribute to the complex formation of body image, as well as to its disturbances. In particular, lower interoceptive accuracy and awareness are associated with body-image concerns. We provide a potential mechanistic explanation of the link between interoception and body image, which aims to integrate interoceptive and exteroceptive representations of the body. The suggested link between interoception and body image can inform new empirically testable hypotheses on the underlying neurocognitive processes that are central to body image concerns and disturbances, and motivate relevant clinical implications. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the bodily-self in Restrictive Anorexia, focusing on two basic aspects related to the bodily self: autonomic strategies in social behavior, in which others' social desirability features, and social cues (e.g., gaze) are modulated, and interoception (i.e., the sensitivity to stimuli originating inside the body). Furthermore, since previous studies carried out on healthy individuals found that interoception seems to contribute to the autonomic regulation of social behavior, as measured by Respiratory Sinus Arrhythmia (RSA), we aimed to explore this link in anorexia patients, whose ability to perceive their bodily signal seems to be impaired. To this purpose, we compared a group of anorexia patients (ANg; restrictive type) with a group of Healthy Controls (HCg) for RSA responses during both a resting state and a social proxemics task, for their explicit judgments of comfort in social distances during a behavioral proxemics task, and for their Interoceptive Accuracy (IA). The results showed that ANg displayed significantly lower social disposition and a flattened autonomic reactivity during the proxemics task, irrespective of the presence of others' socially desirable features or social cues. Moreover, unlike HCg, the autonomic arousal of ANg did not guide behavioral judgments of social distances. Finally, IA was strictly related to social disposition in both groups, but with opposite trends in ANg. We conclude that autonomic imbalance and its altered relationship with interoception might have a crucial role in anorexia disturbances. [ABSTRACT FROM AUTHOR]

Interoception and exteroception for body signals are two different ways of perceiving the self: the first from within, the second from outside. We investigated the relationship between Interoceptive Accuracy (IAcc) and external perception of the body and we tested if seeing the body from an external perspective can affect IAcc. Fifty-two healthy female subjects performed a standard heartbeat perception task to assess the IAcc, before and after the Body Image Revealer (BIR), which is a body perception task designed to assess the different aspects of body-image. The performance of the lower IAcc group in the heartbeat perception task significantly improved after the exteroceptive task. These findings highlight the relations between interoceptive and exteroceptive body-representations, supporting the view that these two kinds of awareness are linked and interact with each other. [ABSTRACT FROM AUTHOR]

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 (Mage=45.5, 39 females) and 45 healthy controls (Mage=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. [ABSTRACT FROM AUTHOR]

Interoceptive and exteroceptive information are both essential for the construction and update of self-awareness. Whereas several studies have shown how interoceptive accuracy or cardiac feedback influences body-awareness, no studies have looked at the reverse effect, namely how exteroceptively-driven changes in body-ownership and self-identification can influence individuals' ability to detect internal bodily signals. We exposed participants to the Rubber Hand Illusion (Experiment 1) and to the Enfacement Illusion (Experiment 2), and tested how this change in the sense of body-ownership and self-identification affected their interoceptive accuracy (IAcc). The heartbeat-counting task was used to measure IAcc before the bodily illusions, and then the same task was interleaved with periods of visuo-tactile stimulation, during which synchronous and asynchronous multisensory stimulation was applied. We found that a change in body-ownership significantly improved performance of participants with lower interoceptive accuracy. In contrast, a change in self-identification significantly decreased performance of participants with higher interoceptive accuracy. These results suggest that changes in different domains of self-awareness can differentially impact individuals' ability to accurately detect signals arising from within the body, highlighting the distinct role that interoceptive signals play for different facets of bodily self-consciousness. [ABSTRACT FROM AUTHOR]

Objective: Previous studies report reduced interoceptive abilities in anorexia nervosa (AN) using various methods. Recent research suggests that different levels of interoceptive processes aiming at different subdomains of interoceptive abilities must be further distinguished as these levels can be differentially affected. Two important levels refer to interoceptive accuracy (IA) derived from objective performance tasks such as the heartbeat detection task, and interoceptive sensibility (IS) as assessed by self-report. There is a lack of studies investigating both IA and IS in AN, and examining them in the time course of therapy. Aim of the pilot study was to evaluate the different interoceptive processes – especially IA and IS – in the time course of therapy.Methods: Fifteen patients with AN (restricting type) from the Psychosomatic Clinic in Windach were investigated three times (T1, T2, T3) during a standardized cognitive-behavioral therapy and compared to fifteen matched healthy controls assessed at Ulm University in a comparable design. All participants performed the heartbeat detection task examining IA and completed standard psychological assessments including an assessment of IS. Results: Patients with AN showed a significantly decreased weight, higher levels of depression and both reduced IA and IS compared to healthy controls at T1. Following therapy, patients recovered in terms of weight and depression symptomatology. A descriptive trend for recovering from IA and IS was observed. Discussion: Our findings suggest that interoceptive deficits are present in recovered patients. Therefore, further investigations are needed with more patients, differentiating between relapsed and recovered patients, and more specific training methods to improve interoceptive processes.

Background: Interoceptive abilities are known to be affected in anorexia nervosa (AN). Previous studies could show that private self-focus can enhance interoceptive accuracy (IAcc) in healthy participants. As body dissatisfaction is high in AN, confrontation with bodily features such as the own face might have a directly opposed effect in AN. Whether patients with AN can benefit from self-focus in their IAcc and whether this pattern changes over the time-course of cognitive behavioral therapy was investigated in this study. Methods: 15 patients with AN from the Psychosomatic Clinic in Windach were assessed three times in the time course of a standardized cognitive-behavioral therapy. They were compared to 15 controls, recruited from Ulm University and tested in a comparable setting. Both groups performed the heartbeat perception task assessing interoceptive accuracy (IAcc) under two conditions either enhancing (Self) or decreasing (Other) self-focused attention. Furthermore, body dissatisfaction was assessed by a subscale of the Eating Disorder Inventory 2. Results: Patients with AN scored higher in IAcc when watching others’ faces as compared to one’s own face while performing the heartbeat perception task. The opposite pattern was observed in controls. IAcc remained reduced in AN as compared to controls in the time-course of cognitive-behavioral therapy, while body-dissatisfaction improved in AN. High body dissatisfaction was related to poorer IAcc in the Self condition. Conclusions: Our findings suggest that using self-focused attention reduces IAcc in AN while the opposite pattern was observed in controls. Confronting anorexic patients with bodily features might increase body-related avoidance and therefore decrease interoceptive accuracy. The current study introduces a new perspective concerning the role of interoceptive processes in AN and generates further questions regarding the therapeutic utility of methods targeting self-focus in the treatment of AN.

The insular cortex has been considered to be the neural base of visceral sensation for many years. Previous studies in psychology and cognitive neuroscience have accumulated evidence indicating that interoception is an essential factor in the subjective feeling of emotion. Recent neuroimaging studies have demonstrated that anterior insular cortex activation is associated with accessing interoceptive information and underpinning the subjective experience of emotional state.Only a small number of studies have focused on the influence of insular damage on emotion processing and interoceptive awareness. Moreover, disparate hypotheses have been proposed for the alteration of emotion processing by insular lesions. Some studies show that insular lesions yield an inability for understanding and representing disgust exclusively, but other studies suggest that such lesions modulate arousal and valence judgments for both positive and negative emotions.In this study, we examined the alteration in emotion recognition in three right insular and adjacent area damaged cases with well-preserved higher cognitive function. Participants performed an experimental task using morphed photos that ranged between neutral and emotional facial expressions (i.e., anger, sadness, disgust, and happiness). Recognition rates of particular emotions were calculated to measure emotional sensitivity. In addition, they performed heartbeat perception task for measuring interoceptive accuracy. The cases identified emotions that have high arousal level (e.g., anger) as less aroused emotions (e.g., sadness) and a case showed remarkably low interoceptive accuracy. The current results show that insular lesions lead to attenuated emotional sensitivity across emotions, rather than category-specific impairments such as to disgust. Despite the small number of cases, our findings suggest that the insular cortex modulates recognition of emotional saliency and mediates interoceptive and emotional awareness.

Interoception, the sense of the physiological condition of the body, provides a basis for subjective feelings and emotions. Anterior insular cortex activity represents the state of the body and varies according to personality traits, such as emotional susceptibility (ES) – the tendency to experience feelings of discomfort and vulnerability when facing emotionally-laden stimuli. The accuracy of perceiving one’s own bodily signals, or interoceptive accuracy (IAc), can be assessed with the heartbeat perception task, which is the experimental measure used by most of the existing research on interoception. However, IAc is only one facet of interoception. Interoceptive awareness (IAw) is the conscious perception of sensations from inside the body, such as heart beat, respiration, satiety, and the autonomic nervous system sensations related to emotions, which create the sense of the physiological condition of the body. We developed an Italian version of the recent self-report Multidimensional Assessment of Interoceptive Awareness (MAIA), tested its psychometric properties (reliability, dimensionality, and construct validity), and examined its relationship to ES, as assessed using the Emotional Susceptibility Scale, in a sample (n = 321) of healthy Italian psychology students (293 females, mean age: 20.5 years). In a subgroup of females (n = 135), we measured IAc with the heartbeat perception task. We used a series of correlation/regression analyses to examine the complex interplay between the three constructs. We provide further evidence for a substantial independence of the IAc and IAw measures, confirming previous reports and current theoretical models that differentiate between IAc and IAw. Our analyses elucidate the complex relationship between distinct dimensions of IAw and ES, highlighting the need for continued efforts to shed more light on this topic.

Objective: Previous studies report reduced interoceptive abilities in anorexia nervosa (AN) using various methods. Recent research suggests that different levels of interoceptive processes aiming at different subdomains of interoceptive abilities must be further distinguished as these levels can be differentially affected. Two important levels refer to interoceptive accuracy (IA) derived from objective performance tasks such as the heartbeat detection task and interoceptive sensibility (IS) as assessed by self-report. There is a lack of studies investigating both IA and IS in AN and examining them in the time course of therapy. The aim of this pilot study was to evaluate the different interoceptive processes - especially IA and IS - in the time course of therapy. Methods: Fifteen patients with AN (restricting type) from the Psychosomatic Clinic in Windach were investigated three times (T1, T2, T3) during a standardized cognitive-behavioral therapy and compared with 15 matched healthy controls assessed at Ulm University in a comparable design. All participants performed the heartbeat detection task examining IA and completed standard psychological assessments including an assessment of IS. Results: Patients with AN showed a significantly decreased weight, higher levels of depression, and both reduced IA and IS compared to healthy controls at T1. Following therapy, patients recovered in terms of weight and depression symptomatology. A descriptive trend for recovering from IA and IS was observed. Discussion: Our findings suggest that interoceptive deficits are present in recovered patients. Therefore, further investigations are needed with more patients, differentiating between relapsed and recovered patients, and more specific training methods to improve interoceptive processes. [ABSTRACT FROM AUTHOR]

Interoception is the sense of the physiological condition of the body. Modern definitions differentiated three separated sub-constructs: accuracy (IAc), i.e., the ability to detect physiological states, sensibility (IAs), i.e., a self-evaluated measure of interoception, and awareness (IAw) i.e., a metacognitive awareness of the accuracy. Preliminary researches correlated pain with alterations in the interoceptive matrix albeit, to the best of our knowledge, interoceptive alterations in chronic pain conditions have never been studied systematically. We searched for studies that assessed interoception in subjects with chronic pain and compared it to healthy population. Eleven studies were included among different chronic pain conditions. Results suggested that chronic pain subjects might present low IAc and, allegedly, that IAc negatively correlates with symptoms severity in specific disorders. Data were inconclusive for IAs and IAw. The high risk of bias across multiple dimensions suggests to consider these conclusions with cautions. Nonetheless, deficits in interoceptive processes indicate a promising path for new form of therapies, and they require further attention and a more defined line of research. [ABSTRACT FROM AUTHOR]

The processing and perception of individual internal bodily signals (interoception) has been differentiated to comprise different levels and processes involved. The so-called heartbeat-evoked potential (HEP) offers an additional possibility to examine automatic processing of cardiac signals. Knowledge on neural structures potentially supporting different facets of interoception is still sparse. One way to get insights into neuroanatomical function is to manipulate the activity of different brain structures. In this study, we used repetitive transcranial magnetic stimulation (rTMS) and a continuous theta-burst protocol to inhibit specific central locations of the interoceptive network including the right anterior insula and the right somatosensory cortices and assessed effects on interoceptive facets and the HEP in 18 male participants. Main results were that inhibiting anterior insula resulted in a significant decline in cardiac and respiratory interoceptive accuracy (IAc) and in a consistent decrease in perception confidence. Continuous theta-burst stimulation (cTBS) over somatosensory cortices reduced only cardiac IAc and affected perception confidence. Inhibiting right anterior insula and right somatosensory cortices increased interoceptive sensibility and reduced the HEP amplitude over frontocentral locations. Our findings strongly suggest that cTBS is an effective tool to investigate the neural network supporting interoceptive processes. This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'. [ABSTRACT FROM AUTHOR]

Individuals differ in their awareness of afferent information from within their bodies, which is typically assessed by a heartbeat perception measure of 'interoceptive accuracy' (IAcc). Neural and behavioural correlates of this trait have been investigated, but a theoretical explanation has yet to be presented. Building on recent models that describe interoception within the free energy/predictive coding framework, this paper applies similar principles to IAcc, proposing that individual differences in IAcc depend on 'precision' in interoceptive systems, i.e. the relative weight accorded to 'prior' representations and 'prediction errors' (that part of incoming interoceptive sensation not accounted for by priors), at various levels within the cortical hierarchy and between modalities. Attention has the effect of optimizing precision both within and between sensory modalities. Our central assumption is that people with high IAcc are able, with attention, to prioritize interoception over other sensory modalities and can thus adjust the relative precision of their interoceptive priors and prediction errors, where appropriate, given their personal history. This characterization explains key findings within the interoception literature; links results previously seen as unrelated or contradictory; and may have important implications for understanding cognitive, behavioural and psychopathological consequences of both high and low interoceptive awareness. This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'. [ABSTRACT FROM AUTHOR]

Garfinkel and Critchley (2013) recently proposed a three level model of interoception. Only few studies, however, have empirically tested this theoretical model thus far. The present study aimed at investigating (1) the central assumptions of this model, i.e. that Accuracy, Sensibility and Awareness are distinguishable facets of interoception and that Interoceptive Accuracy is the basic level of interoception, and (2) whether cardiovascular activation (as indexed by heart rate) is differentially related to the three facets of interoception. Analyses were conducted on a total sample of N = 159 healthy participants (118 female [74.2%]; mean age = 23.9 years, SD = 3.3, range = 19–45) who performed either the heartbeat tracking task, the heartbeat discrimination task or both. The results suggest that Accuracy, Sensibility and Awareness are empirically distinct facets of interoception, showing no correlation when based on heartbeat tracking, but moderate correlations when based on heartbeat discrimination. The assumption that Interoceptive Accuracy is the basic level of interoception could only be partially confirmed. Instead, we conclude that the level of objective physiological states should be considered as the most basic level of interoceptive signal processing. [ABSTRACT FROM AUTHOR]

Humans have the ability to reflect upon their perception, thoughts, and actions, known as metacognition (MC). The brain basis of MC is incompletely understood, and it is debated whether MC on different processes is subserved by common or divergent networks. We combined behavioral phenotyping with multi-modal neuroimaging to investigate whether structural substrates of individual differences in MC on higher-order cognition (MC-C) are dissociable from those underlying MC on perceptual accuracy (MC-P). Motivated by conceptual work suggesting a link between MC and cognitive perspective taking, we furthermore tested for overlaps between MC substrates and mentalizing networks. In a large sample of healthy adults, individual differences in MC-C and MC-P did not correlate. MRI-based cortical thickness mapping revealed a structural basis of this independence, by showing that individual differences in MC-P related to right prefrontal cortical thickness, while MC-C scores correlated with measures in lateral prefrontal, temporo-parietal, and posterior midline regions. Surface-based superficial white matter diffusivity analysis revealed substrates resembling those seen for cortical thickness, confirming the divergence of both MC faculties using an independent imaging marker. Despite their specificity, substrates of MC-C and MC-P fell clearly within networks known to participate in mentalizing, confirmed by task-based fMRI in the same subjects, previous meta-analytical findings, and ad-hoc Neurosynth-based meta-analyses. Our integrative multi-method approach indicates domain-specific substrates of MC; despite their divergence, these nevertheless likely rely on component processes mediated by circuits also involved in mentalizing. Hum Brain Mapp 37:3388-3399, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background: Interoceptive abilities are known to be affected in anorexia nervosa (AN). Previous studies could show that private self-focus can enhance interoceptive accuracy (IAcc) in healthy participants. As body dissatisfaction is high in AN, confrontation with bodily features such as the own face might have a directly opposed effect in AN. Whether patients with AN can benefit from self-focus in their IAcc and whether this pattern changes over the time-course of cognitive behavioral therapy was investigated in this study. Methods: Fifteen patients with AN from the Psychosomatic Clinic in Windach were assessed three times in the time course of a standardized cognitive-behavioral therapy. They were compared to 15 controls, recruited from Ulm University and tested in a comparable setting. Both groups performed the heartbeat perception task assessing IAcc under two conditions either enhancing ("Self") or decreasing ("Other") self-focused attention. Furthermore, body dissatisfaction was assessed by a subscale of the Eating Disorder (ED) Inventory 2. Results: Patients with AN scored higher in IAcc when watching others' faces as compared to one's own face while performing the heartbeat perception task. The opposite pattern was observed in controls. IAcc remained reduced in AN as compared to controls in the time-course of cognitive-behavioral therapy, while body-dissatisfaction improved in AN. High body dissatisfaction was related to poorer IAcc in the "Self" condition. Conclusions: Our findings suggest that using self-focused attention reduces IAcc in AN while the opposite pattern was observed in controls. Confronting anorexic patients with bodily features might increase body-related avoidance and therefore decrease IAcc. The current study introduces a new perspective concerning the role of interoceptive processes in AN and generates further questions regarding the therapeutic utility of methods targeting self-focus in the treatment of AN. [ABSTRACT FROM AUTHOR]

The present study focuses on the multifaceted concept of self-disturbance in schizophrenia, adding knowledge about a not yet investigated aspect, which is the interoceptive accuracy. Starting from the assumption that interoceptive accuracy requires an intact sense of self, which otherwise was proved to be altered in schizophrenia, the aim of the present study was to explore interoceptive accuracy in a group of schizophrenia patients, compared to healthy controls. Furthermore, the possible association between interoceptive accuracy and patients' positive and negative symptomatology was assessed. To pursue these goals, a group of 23 schizophrenia patients and a group of 23 healthy controls performed a heartbeat perception task. Patients' symptomatology was assessed by means of the Positive and Negative Syndrome Scale (PANSS). Results demonstrated significantly lower interoceptive accuracy in schizophrenia patients compared to healthy controls. This difference was not accounted for participants' age, BMI, anxiety levels, and heart rate. Furthermore, patients' illness severity, attention and pharmacological treatment did not influence their interoceptive accuracy levels. Interestingly, a strong positive relation between interoceptive accuracy and positive symptoms severity, especially Grandiosity, was found. The present results demonstrate for the first time that interoceptive accuracy is altered in schizophrenia. Furthermore, they prove a specific association between interoceptive accuracy and positive symptomatology, suggesting that the symptom Grandiosity might be protective against an altered basic sense of self in patients characterized by higher sensibility to their inner bodily sensations. [ABSTRACT FROM AUTHOR]

Previous studies suggest that patients suffering from bulimia nervosa (BN) have difficulties in perceiving internal bodily signals, mostly assessed by self-report questionnaires. Whether interoception is, in this case, attenuated or not remains an open question. Therefore, interoceptive processes were examined in twenty-three patients with current BN and were compared to healthy participants. We investigated Interoceptive Accuracy (IAc) assessed by the heartbeat detection task and Interoceptive Awareness (IA) assessed by the Eating Disorder Inventory-2. Patients with BN and healthy participants did not differ in terms of IAc when controlling for BMI, depression and anxiety, whereas IA among BN patients was found to have decreased. Although IAc and IA were not related among controls, we observed an inverse correlation in BN, suggesting that an abnormal overlap between these two levels of interoceptive signal processing is present in BN. The current study introduces a new perspective concerning the role of interoceptive processes in BN and generates further questions regarding the therapeutic utility of methods targeting the interaction between different levels of interoception in the treatment of BN. [ABSTRACT FROM AUTHOR]

Background and Objectives: This study tested whether relatively low levels of interoceptive accuracy (IAcc) are associated with body dysmorphic disorder (BDD) symptoms. Additionally, given research indicating that power attunes individuals to their internal states, we sought to determine if state interoceptive accuracy could be improved through an experimental manipulation of power..Method: Undergraduate women (N = 101) completed a baseline measure of interoceptive accuracy and then were randomized to a power or control condition. Participants were primed with power or a neutral control topic and then completed a post-manipulation measure of state IAcc. Trait BDD symptoms were assessed with a self-report measure.Results: Controlling for baseline IAcc, within the control condition, there was a significant inverse relationship between trait BDD symptoms and interoceptive accuracy. Continuing to control for baseline IAcc, within the power condition, there was not a significant relationship between trait BDD symptoms and IAcc, suggesting that power may have attenuated this relationship. At high levels of BDD symptomology, there was also a significant simple effect of experimental condition, such that participants in the power (vs. control) condition had better interoceptive accuracy. These results provide initial evidence that power may positively impact interoceptive accuracy among those with high levels of BDD symptoms..Limitations: This cross-sectional study utilized a demographically homogenous sample of women that reflected a broad range of symptoms; thus, although there were a number of participants reporting elevated BDD symptoms, these findings might not generalize to other populations or clinical samples.Conclusions: This study provides the first direct test of the relationship between trait BDD symptoms and IAcc, and provides preliminary evidence that among those with severe BDD symptoms, power may help connect individuals with their internal states. Future research testing the mechanisms linking BDD symptoms with IAcc, as well as how individuals can better connect with their internal experiences is needed.. [ABSTRACT FROM AUTHOR]