What do measures of self-report interoception measure? Insights from a systematic review, latent factor analysis, and network approach

Interoception after frontal brain injury: A systematic review

OBJECTIVE

Interoception is crucial for emotional processing. It relies on the bidirectional connections between the insula, a crucial structure in interoception, and the frontal lobe, which is implicated in emotional experiences. Acquired frontal brain injury often leads to emotional disorders. Our goal was to explore the interoceptive profiles of patients with frontal lesions with or without insular involvement.

METHOD

Given the neuroanatomical links between interoception and emotions, we conducted a systematic Preferred Reporting Items for Systematic Reviews and Meta-analyses guided review of studies assessing at least one dimension of interoception in adults with acquired frontal injuries, with or without associated insular lesions.

RESULTS

Seven articles were included. The review indicated that interoceptive accuracy declines after frontal injuries. The two studies that investigated interoceptive sensitivity found lower scores in patient groups. Finally, inconsistent results were found for interoceptive metacognition after frontal damage.

CONCLUSIONS

This review is the first to explore interoceptive disorders after acquired frontal brain injury. The findings reveal deficits in cardiac interoceptive accuracy and interoceptive sensitivity following frontal damage. Inconsistent results were observed for interoceptive metacognition. Further research is needed to confirm the presence of interoceptive deficits following a frontal lesion. Additionally, the relationship between interoceptive deficits and emotional disorders, often reported after frontal brain injury, should be investigated.

Predicting fluctuations in cardiac interoceptive accuracy and sensibility through additional heart rate variability reductions in everyday life

Cardiac interoception, assessed in terms of accuracy (IAcc) and sensibility (IS; beside others), is important for health and wellbeing. Ecological momentary assessment studies exploring the dynamics of cardiac interoception showed substantial fluctuations of IAcc and IS in everyday life. States of increased (physiologically indicated) stress, such as decreased heart rate variability (HRV), may hamper interoceptive skills, while more relaxed states (higher HRV) seem to go along with increased IAcc. We built on this and investigated if higher (physiological) stress indicated via HRV reductions independent of metabolic needs (i.e., additional HRV reduction, AddHRVr) could (differentially) predict IAcc and IS, respectively. In an initial sample of 119 participants, with data of (up to) three consecutive days, we simulated the predictive value of AddHRVr. We found that AddHRVr before an ambulatory cardiac interoception task predicted poor IAcc and higher IS. We replicated this pattern of findings in an independent sample of 66 participants. Both studies provide first insights into the dynamics of IAcc and IS in daily life, which seems to differ when following AddHRVr. This lays the groundwork for just in time adaptive interventions (JITAIs) supporting individuals in states of high vulnerability and promoting cardiac interoceptive skills.

Measuring interoception from infancy to childhood: A scoping review

BACKGROUND

Interoception is the ability to perceive, understand, and respond to internal bodily signals. Despite its importance, our knowledge of interoceptive abilities in the early stages of development remains limited. Delays or atypical patterns in interoceptive development may serve as early indicators of potential developmental psychopathology. Thus, assessing interoception in infancy and early childhood is essential for advancing our understanding of both typical and atypical developmental pathways.

OBJECTIVE

This scoping review summarises existing evidence regarding interoception from infancy to childhood and identifies the most common methods for assessing interoception in neurotypical pediatric populations.

DESIGN

A literature review was performed through a robust search of three scientific databases.

RESULTS

Among 663 studies, 24 articles met the inclusion criteria. The most commonly used methods in infancy were looking-time paradigms and brain-based implicit measures, such as Heart-Evoked Potentials (HEP). Researchers predominantly used child-adapted versions of Heart Tracking Tasks (HTT) for preschool-aged children. The primary methods for investigating interoceptive abilities among school-aged children included HTTs and self-report measures. Only one study used fMRI to examine mind-body connections in childhood, while two relied on parent reports.

CONCLUSIONS

This review offers a comprehensive overview of past and current methods for measuring interoception in the literature. It highlights the strengths and limitations of existing methodologies and presents recommendations to enhance our understanding of interoception in early human development.

The relationship between sensory phenomena and interoception across the obsessive-compulsive spectrum: a systematic review

BACKGROUND

Uncomfortable sensations preceding repetitive behaviours, known as sensory phenomena, have been documented across the obsessive-compulsive spectrum. Indirect evidence suggests altered interoception may play a role in these shared experiences of sensory phenomena; however, research explicitly measuring this relationship is limited. The current systematic review aimed to establish the nature of sensory phenomena and interoception in obsessive-compulsive and related disorders (OCRDs) and tic disorders as potential maintaining factors of these disorders.

METHODS

PsycINFO, PubMed, and Scopus databases were searched from 2007 to April 2024, yielding 65 studies.

RESULTS

While the majority of studies presented low risk of bias, significant overlap and ambiguity characterised the measurement and conceptualisation of sensory phenomena and interoception. Overall, higher sensory phenomena was associated with greater symptom severity in several obsessive-compulsive spectrum disorders. Obsessive-compulsive disorder and tic disorder samples were characterised by lower interoceptive accuracy, with mixed findings on interoceptive sensibility. Some limited research emerged suggesting altered interoceptive abilities may be associated with greater sensory phenomena in obsessive-compulsive disorder and tic disorders.

CONCLUSIONS

Sensory phenomena are experienced across the obsessive-compulsive spectrum. Future research should explore interoceptive abilities across the OCRDs, and build upon evidence supporting a relationship between sensory phenomena and interoception in OCD and tic disorders.

TRIAL REGISTRATION

CRD42023422817.

Psychometric network analysis of the Multidimensional Assessment of Interoceptive Awareness, version 2 (MAIA-2) in Peruvian adults

Interoception is a complex, multidimensional construct that refers to the nervous system's processing of internal bodily signals. Currently, there are no comprehensive measurement tools available to capture the full complexity of interoception. The Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), is a widely accepted and utilized interoceptive questionnaire that measures the multiple dimensions of conscious interoception through self-report. The aim of this study was to demonstrate the validity of a new Spanish translation of the MAIA-2 in Peruvian adults and to examine the dimensionality of the MAIA-2. A total of 414 Peruvian participants residing in Lima (Peru) were included; 85% were young adults between 18 and 27 years. The fit of the structural equation model (SEM) was assessed using confirmatory factor analysis (CFA). The dimensionality of the MAIA-2 was assessed using bootstrap exploratory bootstrap graph analysis (bootEGA). The results of the CFA suggest an oblique model (8 factors, 34 items) with modifications (items 11, 12, and 15 deleted). The bootEGA analyses indicate that a five-dimensional model is more parsimonious. These findings suggest that the MAIA-2 may have fewer dimensions than the original eight-dimensional theoretical model. The Peruvian Spanish version of the MAIA-2 proves to be a valid and reliable tool for assessing interoception in Peruvian adults, though slight variations in the dimensional structure were observed compared to the original model. This provides a solid basis for future research and clinical applications in Spanish-speaking contexts.

Diminished Interoceptive Accuracy in Attention-Deficit/Hyperactivity Disorder: A Systematic Review

Interoception is the perception of one's internal physiological state. Altered interoception may play a role in the pathogenesis of attention-deficit/hyperactivity disorder (ADHD). We reviewed the literature on interoception and ADHD symptoms (inattention, hyperactivity/impulsivity, executive function, emotional dysregulation) in individuals with and without the disorder. Studies included assessments of interoception and ADHD symptoms in (1) individuals with/without diagnoses of ADHD or (2) the general population. Interoception assessments included objective measures (heartbeat-tracking test) and self-report questionnaires. The literature search included the PubMed/MEDLINE, PsychINFO, CINAHL and Scopus databases. A protocol was prospectively registered in the PROSPERO database (CRD #42022351726); the PRISMA guidelines directed reporting. The Newcastle-Ottawa scale was adapted to evaluate study quality. Of 636 articles identified, 17 articles (based on 18 studies) met inclusion criteria. Five studies compared interoception in participants with/without ADHD, and three found that interoception was reduced in participants with ADHD. One study compared interoception between presentations of ADHD, finding no differences. Twelve studies assessed the association of ADHD symptoms and interoception in the general population. Overall, results suggested that interoception is reduced in individuals who reported higher symptoms of inattention, hyperactivity, impulsivity, emotional dysregulation, and executive dysfunction. Studies were of moderate quality; issues included small sample sizes and inadequate reporting. Individuals with ADHD may have decreased interoception compared to individuals without. Interoception is negatively associated with ADHD symptoms in the general population. Interventions focused on improving interoceptive abilities may provide an avenue for ADHD treatment. Future work should consider the role of culture in interoception.

Operationalisation of interoceptive expectations: A novel paradigm to measure detection and Adjustment to Interoceptive Discrepancy

Interoception is a bidirectional process, with both descending predictions and ascending sensation playing a role in the regulation and perception of homeostatic states. Mistuning of both streams has been associated with psychopathology in mental disorders, including hyperprecise prior beliefs and altered sensory representations. However, empirical research has typically focused on associations between self-report scales and objective physiology during rest or bodily perturbations, without manipulating or measuring descending. Therefore, we developed the novel Adjustment to Interoceptive Discrepancy (AID) paradigm, that builds and then violates interoceptive beliefs to measure expectations and adjustment of expectations over subsequent trials following an unexpected stimulus. We validated this paradigm in the nociceptive domain in a total of 57 university-aged participants. The AID paradigm successfully induced interoceptive discrepancy (i.e., a difference between expectation and perception ratings) that was resolved as participants adjusted expectations appropriately across subsequent trials. This adjustment was more rapid for stimuli that were perceived as more versus less intense than expected. Notably, there were individual differences in the pattern of this adjustment, revealing different strategies in how individuals adjust to unexpected interoceptive sensations, although these were unrelated to interoceptive sensibility scores. Overall, the AID paradigm provides a useful method to assess interoception across expected versus unexpected stimuli, to probe interindividual differences of interoceptive predictions, and ultimately to enable research on the bidirectional processing of internal stimuli in mental health.

The role of interoception in lifestyle factors: A systematic review

BACKGROUND

Interoception, the perception of the internal state of the body, offers an underrepresented and intriguing potential avenue for altering lifestyle-related behaviors. Interoception is intrinsically related to maintaining homeostasis and the flexible allostatic regulation of complex demands. Internal bodily states may also be influenced by lifestyle factors and related problems. This systematic review aimed to provide insight into the current state of evidence about the role of interoception in lifestyle factors.

METHODS

Studies from three databases (PubMed, Embase, and Web of Science) were screened for eligibility based on two inclusion criteria: 1) at least one measure of interoception (e.g., interoceptive accuracy, attention, or awareness), and 2) at least one measure of a lifestyle factor (i.e., alcohol consumption, cognitive leisure and relaxation activities, eating behavior, exercise, sleep, or smoking). Risk of bias was assessed using an adjusted quality score checklist, consisting of five items related to study design, population size, exposure measurement, outcome measurement, and adjustment for confounders.

RESULTS

The review included 73 studies. Out of the included studies, 51 measured interoceptive accuracy and 36 measured interoceptive attention. Six studies quantified interoceptive awareness. In terms of lifestyle factors, 26 studies on cognitive leisure and relaxation activities, 19 studies on eating behavior, 12 studies focused on alcohol consumption, 10 studies on exercise, five studies on smoking, and four studies on sleep were identified. Findings show positive relations between interoceptive domains and cognitive leisure and relaxation activities, eating behavior, and exercise. Conversely, the consumption of alcohol is negatively related to interoceptive domains. Studies in the smoking and sleep lifestyle factors were sparse and of varying methodological quality.

DISCUSSION

The findings of this review show that interoceptive domains are associated with various lifestyle factors, but the quality of the evidence is limited. Future longitudinal studies with more objective measures of interoception are needed in order to better understand the interrelations between interoception and lifestyle factors.

Eating Pathology and Interoceptive Sensibility Using the Brief Multidimensional Assessment of Interoceptive Awareness-2: Can There be Too Much of a Good Thing?

This study evaluated the factorial structure and invariance of the Multidimensional Assessment of Interoceptive Awareness-v2 (MAIA-2). We also investigated incremental validity of the MAIA-2 factors for predicting eating pathology beyond appetite-based interoception. US-based online respondents (N = 1294; Mage=48.7 ± 18.4; 63% cis women; 78% White) were sampled. We conducted hierarchical stepwise regressions, dominance analysis, and multiple-group confirmatory factor analyses across age, gender, and eating disorder symptoms. An 8-factor, 24-item Brief MAIA-2 (BMAIA-2) model showed optimal fit. Using strict criteria (Δ CFI > 0.002), configural, metric, and scalar invariance were supported. After controlling for appetite-based interoception, higher scores on body listening, noticing, and emotional awareness unexpectedly predicted worse eating pathology, while higher scores on not worrying, not distracting, and trusting predicted less eating pathology, as hypothesized. Dominance analysis showed no subscales contributed >2% unique variance to global disordered eating beyond appetite-based interoception. For loss of control eating, however, not worrying was the dominant BMAIA-2 predictor, explaining 5% unique variance beyond appetite-based interoception. Research supported the relevance of multiple interoceptive sensibility dimensions captured by the BMAIA-2 to understanding eating-based pathology. Future studies should consider assessing its incremental validity using behavioral tasks and autonomic biomarkers of interoception to better understand the complex interplay among interoceptive skills and eating behavior.

Discrepancies in the Definition and Measurement of Human Interoception: A Comprehensive Discussion and Suggested Ways Forward

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.

Interoceptive ageing and the impact on psychophysiological processes: A systematic review

Interoception, the perception and response to internal bodily states, significantly influences physical and mental wellbeing. While ageing is associated with interoceptive decline, research has primarily examined selective dimensions of interoception. Understanding these changes is vital as the global population ages, addressing age-related health issues and sustaining psychological wellbeing. This systematic review synthesised findings from 22 studies on age-related interoceptive changes and their impact on psychophysiological processes. Results showed age-related declines (48.4 %), no age differences (32.3 %), an age-related increase (16.13 %), and an inverted U-shaped curvilinear relationship (3.23 %) in interoceptive sensitivity across age groups and interoceptive dimensions. Three patterns emerged regarding psychophysiological processes in older adults: altered mind-body connections with age were associated with reduced high-arousal and increased positive emotional experiences, cognitive protective effects, and improved body representation that correlated with better interoceptive sensitivity. These patterns indicate the complex relationships between interoceptive ageing and psychophysiological processes, showing both, aspects of decline and compensatory mechanisms. We propose future research avenues to elucidate the functional significance of different interoceptive dimensions across the lifespan for optimised psychological wellbeing and health behaviours in older adults.

Interoceptive Mechanisms and Emotional Processing

Interoception, the sensing of internal bodily signals, is intricately linked with the experience of emotions. Various theoretical models of emotion incorporate aspects of interoception as a fundamental component alongside higher-order processes such as the appraisal of internal signals guided by external context. Interoception can be delineated into different dimensions, which include the nature of afferent signals, the accuracy with which they can be sensed, their neural processing, and the higher-order interpretation of these signals. This review methodically evaluates these interoceptive dimensions through empirical research to illustrate their role in shaping emotions. Clinical and neurodevelopmental conditions characterized by altered emotional profiles, such as anxiety, depression, schizophrenia, posttraumatic stress disorder, emotionally unstable personality disorder, and autism, exhibit distinct changes in interoception. Various therapeutic approaches, including behavioral, pharmacological, and psychological strategies, may be efficacious for treating conditions associated with emotional alterations by targeting interoceptive mechanisms.

Sensory Processing and Anxiety: Within and Beyond the Autism Spectrum

In this article, we briefly overview how the expression, measurement, and treatment of anxiety in autism may be different from the general population. We review the literature on links between sensory processing differences and anxiety, which show transdiagnostic patterns but are an especially prominent feature of anxiety in autism. Specifically, we focus on how the sense of interoception, i.e., how we perceive sensory information from within our bodies, contributes to anxiety in autism. We present new findings integrating multimodal interoceptive measures and total anxiety symptoms in a sample of n = 38 non-autistic and n = 43 autistic individuals, ages 8-55 years. Using principal components analysis, we found two components relating to interoceptive confusion (i.e., self-reported ability to localize and interpret interoceptive cues): one component that closely relates to anxiety symptoms and one component that is distinct from anxiety. Interoceptive perception (i.e., performance on a lab-based task) was uniformly related to interoceptive confusion when distinguished from anxiety but showed complex relations with total anxiety symptoms. Combined, these findings suggest meaningful subtypes of interoceptive difficulties and their interrelationship with anxiety. We present conclusions and future directions for consideration of individual differences, toward creating a personalized understanding of anxiety-interoception links.

The relationship between self-reported interoception and anxiety: A systematic review and meta-analysis

Interoception, the processing of internal bodily sensations, is associated with various mental health conditions. In particular, anxiety is often considered to be the prototypical interoceptive disorder. However, empirical evidence is mixed, with meta-analytic work reporting no relationship between anxiety and cardiac interoceptive accuracy. Less explored, however, are the mixed results relating to anxiety and self-reported interoception. This meta-analysis of 71 studies explored the relationship between self-report measures of interoception and anxiety. Across 12 measures (20 subscales), anxiety was associated with increased negative evaluations of, frequency of, and sensitivity to, bodily signals. Anxiety was also associated with greater (negative) attention to bodily signals, and difficulties describing bodily signals and emotions. However, anxiety was not associated with the use of bodily signals to inform emotions (e.g., noticing emotionally induced bodily signals). Results are discussed considering the overlap between anxiety and interoception questionnaires, the lack of specificity of certain measures, and the potential confound of individual differences in questionnaire interpretation. We also discuss limitations of anxiety measures and the clinical relevance of findings.

How well can you tell? Success of human categorisation of horse behavioural responses depicted in media

Horses employ a range of subtle to overt behaviours to communicate their current affective state. Humans who are more cognisant of their own bodily sensations may be more attuned to recognising affective states in horses (Equus caballus) thereby promoting positive human-horse interactions. This study investigated human ability to categorise human-horse interactions depicted in media relative to equine behaviour experts and compared participant scores to their level of interoception. Using an online survey, participants (n = 534) categorised 31 photographs and videos as (overt) positive, likely (subtle) positive, neutral, likely (subtle) negative or (overt) negative human-horse interactions from the horse's point of view and completed the Multidimensional Assessment of Interoceptive Awareness questionnaire (MAIA-2) to assess their level of interoception. Demographic information was also collected (age, gender, education, level of experience with horses, location). Participants differed from expert categorisations of horse affective states across all categories, exactly matching experts only 52.5% of the time and approximately matching experts for positive and negative valence 78.5% of the time. The MAIA-2 did not predict participant ability to accurately categorise human-horse interactions. Women outperformed men in categorising overt positive, overt negative and subtle negative human-horse interactions. Increased levels of education and greater experience with horses were associated with improved categorisation of certain human-horse interactions. More training or awareness is needed to recognise behavioural indicators of horse affect to guide appropriate human-horse activities that impact horse welfare.

A systematic review and meta-analysis of the relationship between subjective interoception and alexithymia: Implications for construct definitions and measurement

Although research indicates that self-reported interoception is associated with deficits in identifying and describing emotional experience, and externally oriented thinking styles (alexithymia), this relationship appears moderated by how interoception is measured. A systematic review and meta-analyses examined the association between self-reported interoception and alexithymia, investigating how different interoceptive questionnaires relate to alexithymia at global and facet levels. PsychINFO, PubMed, Scopus, and Web of Science databases were searched with predefined terms related to self-reported interoception and alexithymia. Three reviewers independently assessed articles, extracted data, and undertook risk of bias assessment. Thirty-two cross-sectional studies published between 1996 and 2023 were included. Random-effects meta-analyses and narrative synthesis indicated that global alexithymia was positively associated with measures of interoceptive confusion, autonomic nervous system reactivity, and heightened interoceptive attention, and inversely associated with interoceptive accuracy and adaptive interoception, indexed by composite Multidimensional Assessment of Interoceptive Awareness scores, but particularly interoceptive trusting, self-regulation, and attention regulation. These patterns were observed for alexithymic facets and stronger in magnitude for difficulty identifying feelings and difficulty describing feelings, relative to externally oriented thinking. Overall, results suggested that the association between self-reported interoception and alexithymia differs as a function of the interoceptive self-report. The review highlighted issues with construct definition and operationalisation and determined that existing interoceptive self-reports broadly capture maladaptive and adaptive sensing, attention, interpretation, and memory. The findings underscore the importance of specifying interoceptive constructs and using appropriate assessments to improve convergence between constructs and measurements, further suggesting potential clinical utility in using existing self-reports to measure interoception and alexithymia, facilitating interventions targeting mind-body connections.

Linking the inner and outer mental representations of the body to social cognition skills: A systematic review and meta-analysis

An interesting interpretation of embodiment highlights the critical role of mental body representations (BR), including motor, somatosensory, and interoceptive formats, for social cognition. However, the nature of this relationship is still debated at the empirical level, with various studies arriving at different conclusions. Here, we present a systematic review and meta-analysis aimed to summarize data from 3466 participants in 21 studies to provide a more comprehensive understanding of the relationship between inner and outer BR and social cognition. We focused on two core social cognition aspects: empathy and Theory of Mind (ToM). Concerning the inner BR, our meta-analytic findings reveal a significant correlation between specific interoceptive dimensions (i.e., interoceptive sensibility and accuracy) and social cognition, which was stronger for empathy than ToM. Conversely, although further research is needed, functional BR that mainly involve the outer body processing (i.e., nonaction-oriented BR) may show positive links with ToM. These findings point to specific interactions between BR and social cognition skills, supporting multi-faceted and embodied social cognition models. However, we also identified critical knowledge gaps and highlighted the need for further investigation to deepen our theoretical understanding of these relationships and their implications for clinical practice.

He Who Seeks Finds (Bodily Signals): German Validation of the Interoceptive Attention Scale (IATS) and its Relationship with Subclinical Psychopathology

Alterations in interoception have been linked to psychopathology. Recent findings suggest that both the attention to and the accuracy of, interoceptive perceptions may be oppositely related to subclinical symptomatology. Thus, providing well-validated tools that tap into these interoceptive processes is crucial for understanding the relation between interoceptive processing and subclinical psychopathology. In the current study (N = 642), we aimed to (1) validate the German version of the Interoceptive Attention Scale (IATS; Gabriele et al., 2022), and (2) test the differential association of self-reported interoceptive attention and accuracy with subclinical symptomatology, including alexithymia, depressive, and anxious symptomatology. We observed that a one-factor solution is a well-fitting model for the IATS. Further, the IATS showed good internal consistency, convergent, and divergent validity, but poor test-retest reliability. Self-reported interoceptive attention and accuracy were unrelated to each other. However, IATS scores were positively related to all measures of psychopathology (except depressive symptomatology), whereas self-reported interoceptive accuracy scores showed negative or nonsignificant relations with these. Our data suggest that the IATS is a good instrument to measure self-report interoceptive attention in the German population. Further, we highlight the need to distinguish between constructs of interoception to better understand the relation between interoception and psychopathology.

Extreme weight conditions impact on the relationship between risky decision-making and interoception

Anorexia nervosa (AN) and obesity (OB) lie on the two ends of the broad spectrum of extreme weight conditions (EWC). Both disorders entail the constant risk to one's body integrity. Importantly, risk-taking is supported by internal signals, the perception of which is typically distorted in EWC. In this study, we sought to characterize in EWC: (i) risky decision-making by contrasting situations in which people process bodies or neutral objects and (ii) the relationship between interoceptive ability and risky decision-making. In a between-subject design, participants with AN restricting type, participants with class 2 OB, and two groups of matched healthy controls (HC) (total N = 160) were administered either the Balloon Analogue Risk Task (BART) or a modified version of it by using a body-related stimulus as a cue in the place of the balloon. Moreover, we collected a measure of interoceptive sensibility and a measure of interoceptive accuracy. Results showed that, when analysing the global population as a continuum based on the BMI, the risk propensity decreased as a function of increased BMI, only for the task involving a body-related stimulus. Moreover, while HC risk propensity toward a body-related stimulus correlated with interoceptive sensibility, such correlation was absent in participants with AN. Individuals with OB, on the opposite pole, showed mixed interaction between interoception and risky decision-making in both tasks. These findings add one more tile to understanding these complex pathologies in the EWC spectrum, opening up future differential rehabilitation scenarios.

Self-reported sensibility to bodily signals predicts individual differences in autobiographical memory: an exploratory study

Recent theoretical perspectives have advanced that autobiographical memory processes are supported by interoception, the perception of internal bodily sensations. Yet, this relationship remains largely underexplored. The present study addressed this critical gap in the literature by systematically investigating the association between self-reported Interoceptive Sensibility and various individual differences measures of autobiographical memory. In Study 1, using a correlational approach in a large sample of participants (N = 247), we identified significant correlations between standardised measures of interoception and the general experience of autobiographical memory and the frequency of involuntary mental time travel. These associations remained significant even after controlling for potential confounding factors in terms of age, gender, and trait affectivity, underscoring their robustness. Study 2 replicated and extended the associations identified in Study 1 in another large participant sample (N = 257), further validating them by accounting for the potential confounding effect of well-being. Our findings demonstrate that individuals' ability to perceive and understand bodily signals robustly relates to how they experience autobiographical memories. By adopting an exploratory approach based on individual differences, our results provide novel and concrete insights into the association between interoception and autobiographical memory, providing a strong foundation for future investigations into the causal mechanisms connecting these two constructs.

Embodied earth kinship: interoceptive awareness and relational attachment personal factors predict nature connectedness in a structural model of nature connection

Previous research has found that nature connectedness, an experiential close connection to nature with cognitive, affective and physical benefits, profoundly impacts individual wellbeing and subsequently increases pro-environmental behaviors. However, little is known about the personal and contextual factors that predict nature connectedness. Testing theory derived from a qualitative interpretative phenomenological analysis study, this research addresses the lacuna in the literature. A structural equation model analysis finds that interoceptive awareness significantly predicts nature connection, that secure attachment to nature significantly explains this relationship, and that these inter-related constructs predict both pro-environmental behavior and wellbeing. This revised model of nature connection indicates important antecedents for the human-nature bond, illuminating in particular that the interpersonal relational processes foundational for close bonding with humans also occur in bonding with nature. Structural equation modeling indicates that emotional awareness is the dimension of interoceptive awareness that most significantly predicts nature connection, suggesting that the more aware a person is of the connection between inner bodily sensations and emotions, the more likely they can bond with nature. Given that interoceptive awareness indicates a coherent relationship with the self, including effective communication between body, mind and feelings, this process is therefore implicated in the capacity for humans to bond with nature. In sum, this present research points to the efficacy of an embodied, secure attachment with nature to help close both the human-nature disconnection chasm, and the environmental value-action gap. Theoretical and methodological implications for research and policy are discussed.

The Relationship Between Pain and Interoception: A Systematic Review and Meta-Analysis

Interoception refers to the ability to sense internal bodily sensations. Research suggests that dysfunctions in interoception may be implicated in the transition to chronic pain, however, little work has examined interoceptive ability in pain states. Therefore, this systematic review aimed to assess whether interoception is altered in individuals experiencing pain. Following a systematic search of 4 electronic databases from inception to February 2023, 28 studies were included. Outcomes of interoceptive accuracy, interoceptive sensibility, and interoceptive awareness were meta-analysed. The risk of bias was assessed, and the certainty of the evidence was evaluated. Meta-analyses indicated that those with chronic pain display reduced interoceptive accuracy and increased interoceptive sensibility. Subgroup analyses indicated that the change in interoceptive sensibility is dependent on the measure used, with those with chronic pain scoring higher on measures focusing on attention to bodily sensations, while also scoring lower on emotional reactivity. No difference in interoceptive awareness was observed between individuals with chronic pain and pain-free controls. Only one study was found that measured interoception in those experiencing acute pain, while another study recruited those experiencing recurrent pain. These findings suggest that while those with chronic pain self-report as more interoceptively aware, they are less accurate at detecting internal bodily signals. Further research investigating domains of interoception in those experiencing acute and recurrent pain is needed. Data should be interpreted with caution as the certainty of evidence was very low for all completed analyses. This review was registered on the PROSPERO International Prospective Register of Systematic Reviews (Registration ID = CRD42022318843). PERSPECTIVE: This review considered the relationship between interoception and pain and found that an individual's ability to accurately sense internal signals is decreased in those with chronic pain, despite them reporting being more aware of internal sensations. However, there remains little research examining interoception in non-chronic pain states.

Interoception in anxiety, depression, and psychosis: a review

Research has examined the relationship between interoception and anxiety, depression, and psychosis; however, it is unclear which aspects of interoception have been systematically examined, what the combined findings are, and which areas require further research. To answer these questions, we systematically searched and narratively synthesised relevant reviews, meta-analyses, and theory papers (total n = 34). Existing systematic reviews and meta-analyses (anxiety n = 2; depression n = 2; psychosis n = 0), focus on cardiac interoceptive accuracy (heartbeat perception), and indicate that heartbeat perception is not systematically impaired in anxiety or depression. Heartbeat perception might be poorer in people with psychosis, but further evidence is needed. Other aspects of interoception, such as different body systems and processing levels, have been studied but not systematically reviewed. We highlight studies examining these alternative bodily domains and levels, review the efficacy of interoception-based psychological interventions, and make suggestions for future research.

Funding

Wellcome Trust UK.

Mindfulness and Interoceptive Awareness: A Network Analysis

ABSTRACT

Higher trait mindfulness is correlated with higher interoceptive awareness. However, there is a gap in understanding which mindfulness dimensions connect to which interoceptive awareness dimensions. This study ( N = 1005) used network analysis to identify central and bridge nodes driving the linkage between mindfulness and interoceptive awareness. Central nodes included trusting body sensations, feeling a sense of calm when bringing awareness to the body, the ability to refocus one's attention from thinking to sensing the body, and the ability to accept all emotions. Bridge nodes included noticing how food and drink affect thoughts, bodily sensations, and emotions; staying alert to the sensations of the body when taking a shower; and noticing and letting go of distressing thoughts and feelings. Future research studies should explore whether mindfulness-based interventions may be more effective by targeting observations of sensations related to eating and the body as well as noticing and letting go of distressing thoughts and feelings.

Somatic symptom distress is not related to cardioceptive accuracy

OBJECTIVE

(Cardiac) interoception was long considered a key mechanism behind symptom perception in persistent somatic symptoms (PSS). In this study, we aimed to extend earlier findings to clarify this potential interoceptive mechanisms of PSS.

METHODS

A cross-sectional sample of 251 participants (23.1% with self-reported functional somatic syndrome) completed a laboratory study with two cardioceptive accuracy tasks (Schandry task and a new cardiac signal detection task) and multiple questionnaires. Somatic symptom distress and associated constructs were assessed with the PHQ-15, as well as with a novel multidimensional questionnaire measure (HiTOP-SF1) derived from the somatoform spectrum of the Hierarchical Taxonomy of Psychopathology (HiTOP). Correlations (frequentist and Bayesian) and structural equation modelling (SEM) helped further investigate the interplay between these variables.

RESULTS

There were no significant correlations between measures of interoception and somatic symptom distress. Self-report and behavioral cardioceptive accuracy measures did not correlate significantly. No significant covariances emerged between diagnostic tools and cardioceptive accuracy; Bayesian analyses supported the lack of association between interoception and symptom perception.

CONCLUSIONS

Cardiac interoception (specifically cardioceptive accuracy) unlikely represents a key mechanism in PSS etiology. We recommend investigating other factors in PSS.

Bodily sensations and bariatric surgery: Links between interoceptive sensibility, intuitive and disordered eating behaviour in obesity and obesity surgery

OBJECTIVE

This study evaluated interoceptive sensibility, intuitive and disordered eating among bariatric candidates, operated individuals and individuals with obesity seeking non-surgical treatment.

METHOD

We recruited 57 individuals with obesity seeking nonsurgical weight-loss (IOB), 84 bariatric candidates (Pre) and 22 individuals post-bariatric surgery (Post) who responded to questionnaires: Multidimensional Assessment of Interoceptive Awareness, Intuitive Eating Scale-2 (IES-2), Dutch Eating Behaviour Questionnaire, Binge Eating Scale, State-Trait Anxiety Inventory, Beck's Depression Inventory.

RESULTS

Overall, the Post group manifested higher scores on 'Body-Listening' (F = 4.95, p = 0.01), 'Emotional Awareness' (F = 8.83, p < 0.001) and 'Trusting' (F = 6.71, p = 0.002) interoceptive dimensions, on the IES-2 total score (F = 5.48, p = 0.007) and 'Reliance on hunger and satiety cues' (F = 31.3, p < 0.001) when age was controlled. The IOB group presented higher scores on emotional (F = 3.23, p = 0.047) and binge eating (F = 5.99, p = 0.004). Among operated individuals, intuitive eating mediated the relationship between interoceptive sensibility dimensions and binge eating: 'Attention regulation' (54%) 'Self-regulation' (75.1%), 'Body listening' (94.09%) and 'Trusting' (84.9%).

CONCLUSIONS

Our results suggest the therapeutic potential of interoceptive sensibility and intuitive eating in obesity management in/beyond the bariatric context.

An Overview of the Bodily Awareness Representation and Interoception: Insights and Progress in the Field of Neurorehabilitation Research

In the last two decades, the scientific literature on so-called body representations has been increasing, and the notion of body awareness (BA) is particularly interesting for neurorehabilitation. In this article, we present results derived from recent studies on this representation, considering the different definitions and explicative models proposed as well as the empirical settings used to test it, providing an extensive overview of these issues. This article discusses the challenge of understanding how we integrate the sensory experiences of proprioception (knowing where our body is in space) and interoception (sensing internal bodily sensations, like hunger of thirst) with our perception of self. This is a difficult problem to analyze because our awareness of our body is inherently linked to our perspective, since the body is the means through which we interact with the world. Presenting the different viewpoints offered by recent theories on this concern, we highlighted that the neurorehabilitation and psychiatric settings offer two important fields useful for the study of BA because in them it is possible to analyze bodily representations by inducing/observing a controlled discrepancy between dysfunctional content and sensory inputs.

The effect of 10-week long yoga training on interoceptive abilities: cross-sectional and longitudinal investigation of cardiac and gastric accuracy

Based on their characteristics, it is likely that mind-body techniques develop interoception, the perception of bodily state. Nevertheless, findings on mindfulness, meditation, yoga, and body scan techniques are inconclusive. Additionally, the methodological scope is not exhaustive, neither in terms of the intervention nor the applied measure of interoception. This study investigated for the first time the effect of regular yoga training on cardiac and gastric perceptual ability (measured with the mental heartbeat tracking task and the water load task, respectively). With the involvement of 90 female university students (yoga group n = 57, control group n = 33) we did not find any connection between baseline heartbeat perception score and gastric fullness. Moreover, the applied 10-week-long regular yoga training did not develop any of the measured interoceptive abilities. We conclude that yoga might develop other abilities than these specific sensations. Very probably, the measured cardiac and gastric perceptual abilities do not represent bodily sensations in general. It would be worth to investigate, however, the effect of longer yoga training on interoception.

Elevated interoceptive deficits in individuals with eating disorders and self-injurious thoughts and behaviors: A replication and extension

INTRODUCTION

People with eating disorders (EDs) frequently report self-injurious thoughts and behaviors (SITBs). We aimed to replicate and extend findings demonstrating greater interoceptive deficits according to SITB severity. We predicted that interoceptive deficits would be greater among people with versus without lifetime SITBs and among those with multiple suicide attempts compared with single attempts or nonsuicidal self-injury. We also predicted that interoception would be increasingly impaired with greater current suicidality severity.

METHOD

Adults (N = 118) seeking ED treatment reported current and lifetime SITBs upon admission to treatment. We used planned contrasts to compare interoceptive deficits (self-reported using the Eating Disorders Inventory) by SITB and current suicidality groups (assessed by self-report and clinical interview).

RESULTS

Interoceptive deficits were greater among people with any SITB history compared to those without. People with multiple suicide attempts did not differ in interoceptive deficits from those with single attempts or only nonsuicidal self-injury. Interoceptive deficits were elevated among those with any current suicidality compared to those with no suicidal symptoms; interoceptive deficits did not differ according to severity of suicidality.

CONCLUSION

Among those with EDs, interoceptive deficits are elevated among those with concurrent SITBs. Interventions aimed at improving interoception may reduce the risk for SITBs.

Sensing the body matters: profiles of interoceptive sensibility in chronic pain adjustment

ABSTRACT

Interoception is critical to health regulation and is often disrupted in individuals with chronic pain (ICPs). Interoceptive sensibility (IS)-the self-reported experience and relationship toward internal states-includes skills such as sensing, interpreting, and using bodily information for self-regulation. Current studies on IS and chronic pain (CP) adjustment are scarce, and how the interplay between different IS skills shapes CP adjustment remains unclear. This cross-sectional study aimed to identify profiles of IS skills among ICPs and examined their associations with pain outcomes and psychological and behavioral risk or protective processes. Individuals with chronic musculoskeletal pain (n = 173; 84.4% women) completed the Multidimensional Assessment of Interoceptive Awareness (MAIA), measures of CP adjustment (depression, anxiety, vitality, pain severity, interference, and physical function), psychological (self-efficacy, catastrophizing, and kinesiophobia), and behavioral processes (activity patterns). A cluster analysis identified 3 IS skills profiles: (1) high IS skills (n = 68), with the highest levels of attention regulation toward bodily sensations, body trust, listening for insight, and self-regulation; (2) low IS skills (n = 29), who distracted less and worried more about bodily sensations, and presented lower-body trust; and (3) mixed IS skills (n = 71), despite good body trust, attention regulation, and low worrying, showed lower awareness of body-mind connections. Interoceptive sensibility skills profiles differed in depression, vitality (fatigue), and psychological or behavioral processes, such as pain-related self-efficacy, catastrophizing, kinesiophobia, and activity pacing. These findings contribute to integrating body-mind connections more explicitly into current theoretical CP models and developing tailored interventions targeting specific IS skills to improve CP adjustment.

Interoception: Where do we go from here?

In recent years, there has been a significant rise in interest in interoception, the processing of internal bodily signals. This interest has been coupled by increased concerns regarding the measurement and conceptualisation of interoception. Focusing on cardiac interoceptive accuracy, I outline what I believe to be the most pressing issues in the field of interoception-specifically the continued reliance on the heartbeat counting task. I then provide an overview of what I believe to be more general limitations concerning how we measure and conceptualise individual differences in interoception and suggestions for a way forward. Specifically, I believe that by moving beyond single measurements, establishing optimal levels of interoceptive accuracy, and refocusing from accuracy to propensity, we may be able to uncover the real-life relevance of interoceptive abilities.

Heightened interoception in adults with fibromyalgia

Previous research suggests that the processing of internal body sensations (interoception) affects how we experience pain. Some evidence suggests that people with fibromyalgia syndrome (FMS) - a condition characterised by chronic pain and fatigue - may have altered interoceptive processing. However, extant findings are inconclusive, and some tasks previously used to measure interoception are of questionable validity. Here, we used an alternative measure - the Phase Adjustment Task (PAT) - to examine cardiac interoceptive accuracy in adults with FMS. We examined: (i) the tolerability of the PAT in an FMS sample (N = 154); (ii) if there are differences in facets of interoception (PAT performance, PAT-related confidence, and scores on the Private Body Consciousness Scale) between an FMS sample and an age- and gender-matched pain-free sample (N = 94); and (iii) if subgroups of participants with FMS are identifiable according to interoceptive accuracy levels. We found the PAT was tolerable in the FMS sample, with additional task breaks and a recommended hand posture. The FMS sample were more likely to be classified as 'interoceptive' on the PAT, and had significantly higher self-reported interoception compared to the pain-free sample. Within the FMS sample, we identified a subgroup who demonstrated very strong evidence of being interoceptive, and concurrently had lower fibromyalgia symptom impact (although the effect size was small). Conversely, self-reported interoception was positively correlated with FMS symptom severity and impact. Overall, interoception may be an important factor to consider in understanding and managing FMS symptoms. We recommend future longitudinal work to better understand associations between fluctuating FMS symptoms and interoception.

Investigating the relationship between self-reported interoceptive experience and risk propensity

Risky behaviour may be associated with visceral experiences, such as increased heart rate. Previous studies examining the relationship between perception of such signals (interoception) and risk-taking typically used behavioural tasks with potential for monetary reward. This approach may be less informative for understanding general risk propensity. In addition, such research does not usually consider the varied ways individuals engage with interoceptive signals. However, examining these different forms of engagement may help us understand how subjective experience of interoception influences risk-taking. As such, we performed two surveys (n = 471, primarily young adults) to examine the relationship between self-reported engagement with interoceptive signals (measured using the Multidimensional Assessment of Interoceptive Awareness) and a generalised measure of risk propensity (the General Risk Propensity Scale). Results indicated that different ways of interpreting or engaging with interoceptive signals were differentially associated with risk propensity. In particular, they provide preliminary evidence that those with the ability to ignore or not worry about visceral signals when they are uncomfortable display greater risk propensity (and these effects may possibly be gender-specific).

Thermosensation and emotion: Thermosensory accuracy in a dynamic thermal matching task is linked to depression and anxiety symptomatology

Interoception is related to the generation of bodily feelings and the awareness of ourselves as 'sentient beings', informing the organism about its bodily needs to guarantee survival. Previous studies have reported links among interoception, emotion processing, and mental health. For example, the alignment of interoceptive dimensions (i.e., accuracy, sensibility, awareness) can predict emotional symptoms, such as anxiety. Here, we aimed to investigate the relationship between the perception of a certain type of skin-mediated interoceptive signal, i.e., thermosensation, and self-reported depression, anxiety, and stress. One hundred seventy participants completed the Depression Anxiety Stress Scale (DASS-21) and a dynamic thermal matching task, a static temperature detection task, and a heartbeat counting task. Our results revealed that self-reported anxiety and depression were related to the perception of temperature on hairy and non-hairy skin, respectively: higher anxiety was related to better performance on the thermal matching task on the forearm, while higher depression was related to poorer performance on dynamic and static temperature tasks on the palm. Discrepancies between thermosensory accuracy and sensibility measures ('trait prediction error') were related to heightened anxiety, in line with previous studies. No significant correlations were found between DASS-21 scores and heartbeat counting accuracy. In conclusion, this study suggests that individual differences in thermosensory perception in different areas of the body are associated with self-reported anxiety and depression.

Assessment of the mind-body connection: preliminary psychometric evidence for a new self-report questionnaire

OBJECTIVES

While interoceptive self-report scales provide a foundation for measuring the mind-body connection, they variably consider other important factors that could influence interpretations of internal bodily sensations and perceptions related to mind-body integration. The proposed Body-Mind Connection Questionnaire (BMCQ) aimed to operationalise the notion that this construct involves three major components: (a) Interoceptive Attention, (b) Sensation-Emotion Articulation, and (c) Body-Mind Values.

METHODS

Following panel review and piloting with the target population, the developed BMCQ was evaluated in 316 participants (189 identifying as female) aged 18-50 (MAge=30.78), alongside established self-report measures of interoceptive sensibility, body awareness, sensory processing sensitivity, and alexithymia. We examined the BMCQ factor structure through exploratory factor analysis and analysed convergent and discriminant validity.

RESULTS

Exploratory factor analysis supported three scales of the BMCQ, which explained 54.03% of variance. Factor loadings (>0.44) and reliability indices (0.74 to 0.85) were acceptable. Inter-scale correlations suggested that the scales are distinct but related (rs=0.38 to 0.59). BMCQ scales were supported by convergent (r=0.33 to 0.67) and discriminant evidence (rs=0.01 to 0.39, p range n.s. to <.05).

CONCLUSIONS

Preliminary psychometric properties indicate that the BMCQ is multidimensional and consists of three constructs that differentially relate to theoretically associated measures. Interoceptive Attention, Sensation-Emotion Articulation, and Body-Mind Values may serve as a basis for efficiently assessing the mind-body connection more holistically, which could be useful for developing interventions aimed at enhancing mind-body integration.

The new measures of interoceptive accuracy: A systematic review and assessment

Conscious interoception, the perception of internal bodily states, is thought to contribute to fundamental human abilities (e.g., decision-making and emotional regulation). One of its most studied dimensions is interoceptive accuracy: the objective capacity to detect internal bodily signals. In the past few years, several labs across the world have started developing new tasks aimed at overcoming limitations inherent in classical measures of interoceptive accuracy. In this systematic review, we identified these tasks (since 2015) for the cardiac, respiratory, and gastrointestinal domains. For each identified task, we discuss their strengths and weaknesses, and make constructive suggestions for further improvement. In the general discussion, we discuss the (potentially elusive) possibility of reaching high validity in the measurement of interoceptive accuracy. We also point out that interoceptive accuracy may not be the most critical dimension for informing current theories, and we encourage researchers to investigate other dimensions of conscious interoception.

A multi-site German validation of the Interoceptive Accuracy Scale and its relation to psychopathological symptom burden

Altered interoception is thought to be implicated in the development of psychopathology. Recent proposals highlight the need to differentiate between dimensions of interoception to better understand its relation to mental health. Here, we validated a German version of the Interoceptive Accuracy Scale (IAS) and investigated the relationship between IAS scores and clinical outcomes, across seven samples from four research centers (N = 3462). The German IAS version was best explained by a one-factor structure that showed acceptable psychometric properties. We replicated previous findings showing a negative association between IAS scores and measures of alexithymia. IAS scores were negatively related to measures of clinical symptomatology (e.g., anxiety, depressive, and somatoform symptoms) and neurotic traits. These findings suggest that the German IAS is a reliable and valid instrument for subjective interoceptive accuracy. Results emphasize the importance of distinguishing between dimensions of interoception to understand its potential modulatory and protective role in psychopathology.

Interoceptive awareness in a Norwegian population: psychometric properties of the Multidimensional Assessment of Interoceptive Awareness (MAIA) 2

BACKGROUND

Interoception plays a vital role in human cognition and emotion and is an increasingly important part of clinical studies of mind-body approaches and mental health. Interoceptive awareness (IA) encompasses numerous mind-body components and can be assessed by employing a self-report measure such as the Multidimensional Assessment of Interoceptive Awareness (MAIA), which has been adapted and validated across several countries and is used in experimental and clinical settings. In this study, the MAIA-2, which was developed due to the psychometric shortages of MAIA, was thoroughly translated, and its psychometric features were examined in a sample of 306 Norwegian-speaking participants (81% females, ages 16 through 66 plus).

METHODS

The participants completed the MAIA-2 Norwegian version (MAIA-2-N) and the COOP/WONCA Functional Assessment Charts measuring psychological, physical, and overall health. The following psychometric qualities of the MAIA-2 were investigated: factor structure, internal consistency, and the moderating role of gender.

RESULTS

Confirmatory Factor Analysis (CFA) revealed that an 8-factor model of MAIA-2-N provided the best fit. Also, a bifactor model revealed a proper fit. Good internal consistency and a moderating role of gender, age, and education on the relationships between certain MAIA-2-N factors and health were observed.

CONCLUSIONS

The MAIA-2-N is an adequate measure of IA in Norwegian-speaking individuals. The factor-structure corresponds with the original MAIA-2 and it shows good internal consistency. Some moderating effects of gender were observed, particularly related to the relationship between IA and physical and psychological state, with the physical state/fitness more closely linked to IA in males and psychological state in females.

Dissociating cognitive and affective empathy across psychopathy dimensions: The role of interoception and alexithymia

This study examined the associations between psychopathy dimensions (triarchic phenotypes and classical factors), empathy domains (cognitive and affective), and interoception (interoceptive attention and accuracy) while accounting for the putative role of alexithymia. A community sample (n = 515) completed an online survey encompassing: Triarchic Psychopathy Measure (boldness, meanness, disinhibition); Levenson Self-Report Psychopathy Scale (primary and secondary psychopathy); Body Perception Questionnaire (interoceptive attention); Interoceptive Accuracy Scale; Toronto Alexithymia Scale. Hierarchical linear regression models were implemented for hypothesis-driven analyses examining the associations between psychopathy, empathy, and interoception while controlling for sex, age, and alexithymia. Exploratory path models were employed to investigate alexithymia and/or cognitive empathy as mediators between interoception and psychopathy. Our results largely confirmed the postulated empathy profiles across psychopathy dimensions, as meanness and primary psychopathy displayed a broad empathy impairment, while disinhibition and secondary psychopathy were only associated with diminished cognitive empathy. Importantly, boldness displayed a unique pattern (enhanced cognitive empathy and reduced affective empathy), further reinforcing its importance within the constellation of psychopathy traits. Contrary to our hypotheses, self-perceived interoceptive attention and accuracy were not associated with either psychopathy dimension after controlling for alexithymia. However, interoceptive accuracy and alexithymia were associated with cognitive empathy, while alexithymia was also positively related to all psychopathy dimensions (as expected), despite the unexpected strong and negative association with boldness. Exploratory analyses suggested significant indirect effects (mediation) between interoceptive accuracy and psychopathy via alexithymia and/or cognitive empathy. These mediating effects must be interpreted with caution and future studies should be designed to formally test this model.

A Primer on Interoception and its Importance in Psychiatry

Interoception is the perception of signals from inside the body. It plays a significant role in the nervous, cardiovascular, respiratory, gastrointestinal, genitourinary, and endocrine systems. It is also closely related to the autonomic nervous system and inflammatory pathways and plays a significant role in our optimal functioning. Recently, interoception has gained more attention in neuropsychiatric research. Anatomical and physiological aspects of interoception like relevant brain areas, the role of the vagus nerve, and the autonomic nervous system are gradually being understood. Different facets of interoception like interoceptive attention, detection, magnitude, discrimination, accuracy, awareness, and appraisal have been proposed and their assessments and importance are being evaluated. Further, interoception is often dysregulated or abnormal in psychiatric disorders. It has been implicated in the psychopathology, etiopathogenesis, clinical features and treatment of mood, anxiety, psychotic, personality and addiction-related disorders. This narrative review attempts to provide a nuanced understanding of the pathway(s), components, functions, assessments, and problems of interoception and will help us to detect its disturbances and evaluate its impact on psychiatric disorders, leading to a better perspective and management. This will also advance interoception-related research.

Self-reported interoceptive accuracy and interoceptive attention differentially correspond to measures of visual attention and self-regard

Background

Interoception, the perception of bodily functions and sensations, is a crucial contributor to cognition, emotion, and well-being. However, the relationship between these three processes is not well understood. Further, it is increasingly clear that dimensions of interoception differentially corresponds to these processes, yet this is only recently being explored. The present study addresses two important questions: Are subjective interoceptive accuracy and interoceptive attention related to self-regard and well-being? And are they related to exteroceptive (visual) attention?

Methods

Participants (N = 98; 29% women; aged 23-64 years) completed: a battery of questionnaires to assess subjective accuracy (how well one predicts bodily sensations), interoceptive attention (a tendency to notice bodily signals), self-regard (self-esteem, self-image, life satisfaction), state negative affect (depression, anxiety, and stress), a self-esteem Implicit Association Task (a measure of implicit self-esteem), and a flanker task to assess visual selective attention. Subjective interoceptive accuracy and attention served as dependent variables. Correlations and principal component analysis was used to establish correlations among variables and determine how, or whether, these measures are associated with subjective interoceptive accuracy or attention.

Results

Greater scores on measures of self-regard, implicit self-esteem, cognition and lower negative affect were broadly associated with greater subjective interoceptive accuracy. Conversely, only explicit self-esteem, satisfaction with life, and self-image corresponded to subjective interoceptive attention. An exploratory analysis with a more inclusive scale of interoceptive attention was conducted. Results of this exploratory analysis showed that the broader measure was a stronger correlate to self-regard than subjective interoceptive accuracy, though it, too, did not correlate with visual attention. In short, both subjective interoceptive accuracy and attention corresponded to well-being and mental health, but only accuracy was associated with exteroceptive attention.

Conclusion

These results add to a growing literature suggesting different dimensions of (subjective) interoception differentially correspond to indices of well-being. The links between exteroceptive and interoceptive attention, and their association with merit further study.

Examination of the two-step water load test as a measure of gastric interoception and associations with eating and weight/shape concerns in a nonclinical sample

OBJECTIVE

The current study extended research examining the validity of the two-step Water Load Test (WLT-II), an objective, laboratory-based measure of gastric interoception, by investigating the validity of the WLT-II in a nonclinical sample and testing its contribution to the prediction of eating and weight/shape concerns.

METHODS

Participants (n = 129, 73.6% cisgender female, M = 20.13 years old) completed the WLT-II Questionnaire and two-step WLT-II, as well as self-report measures of eating and weight/shape concerns (Eating Disorder Examination Questionnaire; EDE-Q) and interoception (Multidimensional Assessment of Interoceptive Awareness-2; Intuitive Eating Scale-2 Reliance on Hunger and Satiety), in the lab at a large southeastern university. Data analysis included repeated measures ANOVA, correlations, and a series of hierarchical linear regressions.

RESULTS

Participants reported considerably more discomfort after the "maximum fullness" trial compared to the "satiation" trial. The WLT-II's objective measure of gastric interoception (sat_%) was not significantly correlated with the self-report measures of interoception and did not predict EDE-Q Dietary Restraint, Eating Shame, or Weight/Shape Concerns. Unexpectedly, greater gastric sensitivity was associated with less EDE-Q Preoccupation/Restriction. Exploratory analyses suggested a possible nonlinear association.

DISCUSSION

These results support the validity of the WLT-II in its ability to create, measure, and distinguish between the states of satiation and maximum fullness. However, results also suggest additional work is needed to better understand what the WLT-II's sat_% measure is capturing, as well as investigate potential nonlinear associations of the WLT-II with disordered eating.

PUBLIC SIGNIFICANCE

Interoception, or the processing of internal body signals, shows important links to disordered eating. Despite the clear relevance of gastric interoception to disordered eating-such as the ability to detect satiety signals-existing research has relied on general, self-report measures of interoception. This study examined the utility of a laboratory-based measure of gastric interoception. Results suggested mixed support for its validity and utility for predicting eating and weight/shape concerns in a nonclinical population.

Alexithymia and Alcohol Use: Evaluating the Role of Interoceptive Sensibility with the Revised Multidimensional Assessment of Interoceptive Awareness

Alexithymia has been linked to risky or problematic alcohol use, with a common interpretation invoking deficient emotion regulation and use of alcohol to cope with distress. An alternative explanation positing a general deficit of interoception in alexithymia suggested that poor awareness of internal cues of overconsumption may promote excessive drinking. The present study assessed predictions based on these hypotheses in 337 young adult alcohol users recruited online. Participants completed validated questionnaire indices of alcohol use, alexithymia, emotion regulation, interoceptive sensibility, and sensitivity to reward and punishment. Alcohol use was positively correlated with alexithymia and reward sensitivity, and negatively correlated with emotion regulation as expected, but was uncorrelated with interoceptive sensibility. Alexithymia was not significantly correlated with most dimensions of interoceptive sensibility but was highly negatively correlated with emotion regulation. Hierarchical regression controlling for demographic variables indicated that alexithymia, emotion regulation, sex, and sensitivity to reward and punishment were significant predictors of alcohol use levels. Bootstrapped mediation test controlling for all other variables indicated mediation of the association between alexithymia and alcohol use by deficient emotion regulation but not interoceptive sensibility. Results supported the emotion regulation deficit interpretation of the association of alexithymia with alcohol use. Limitations concerning interoception measurement, online samples, self-report measures, cross-sectional designs, and collection of data during the COVID-19 pandemic are discussed. Future research could follow up on these findings by testing interoceptive accuracy in addition to interoceptive sensibility in relation to alexithymia and alcohol use.

Investigating Relationships Among Interoceptive Awareness, Emotional Susceptibility, and Fatigue in Persons With Multiple Sclerosis

BACKGROUND

Fatigue is a particularly debilitating symptom for people with multiple sclerosis (MS). Although personality traits and MS have been studied, interoception and emotional susceptibility and their links to fatigue have not yet been explored.

METHODS

Study participants provided demographic information and completed standardized patient-reported outcomes of walking function, physical activity, subjective fatigue, interoceptive awareness, and emotional susceptibility. A subset of participants participated in semistructured interviews discussing fatigue, body sensations, emotions, and their effects on exercise. Quantitative data were analyzed using multiple regression. Qualitative data were analyzed using thematic analysis.

RESULTS

Mean ± SD Fatigue Severity Scale scores (5.0 ± 1.3) indicated that fatigue was a problematic symptom. Mean ± SD Multidimensional Assessment of Interoceptive Awareness, Version 2 (2.8 ± 0.6) and Emotional Susceptibility Scale (3.0 ± 1.0) scores indicated lower levels of interoceptive awareness and emotional susceptibility. Quantitative data indicated no relationship between fatigue and interoceptive awareness (β = -0.20; P = .88) and emotional susceptibility (β = 0.03; P = .83), and neither were these related to physical activity (β = -0.07; P = .64). Qualitative themes indicated strong fatigue experiences involving the whole body and individual limbs, anger and frustration, and effects on physical activity.

CONCLUSIONS

Physically active people with MS report strong sensations of fatigue closely linked to frustration and helplessness. There was agreement between qualitative and quantitative assessments of fatigue but dissonance regarding interoceptive awareness and physical activity. The practice of clinicians, particularly those involved with facilitating or planning physical activity for persons with MS, would benefit from these findings about fatigue.

Are some interoceptive sensibility components more central than others? Using item pool visualisation to understand the psychometric representation of interoception

Interoception refers to the processing of stimuli originating within the body and is widely considered a multidimensional construct. However, there remains a lack of consensus regarding the definition and measurement of the subjective, self-reported component, referred to here as interoceptive sensibility. As a contribution to knowledge on the topic, we sought to examine the construct commonality and distinguishability of seven self-report measures of interoceptive sensibility using Item Pool Visualisation (IPV), an illustrative method that locates item pools from within the same dataset and illustrates these in the form of nested radar charts. Adults from the United Kingdom (N = 802) completed seven measures of interoceptive sensibility, and the data were subjected to IPV. Results demonstrated that, of the included measures, the Multidimensional Assessment of Interoceptive Awareness-2 provided the closest and most precise measurement of the core interoceptive sensibility construct (i.e., core of the entire investigated item pool). The Body Awareness Questionnaire and the Private Body Consciousness Scale were also centrally located measures, while the Body Perception Questionnaire and the Body Responsiveness Scale appear to tap more distal aspects of the core construct. We discuss implications for interpreting complicated data patterns using measures of interoceptive sensibility and, more generally, for measuring the construct of interoceptive sensibility.

On the Embodiment of Social Cognition Skills: The Inner and Outer Body Processing Differently Contributes to the Affective and Cognitive Theory of Mind

A specific interpretation of embodiment assigns a central role to the body representations (BR) in cognition. In the social cognition domain, BR could be pivotal in representing others' actions and states. However, empirical evidence on the relationship between different BR and social cognition, in terms of Theory of Mind (ToM), in the same sample of participants is missing. Here, this relationship was explored considering individual differences in the action-oriented BR (aBR), nonaction-oriented BR (NaBR), and subjective predisposition toward internal bodily sensations (interoceptive sensibility, ISe). Eighty-two healthy adults were given behavioral measures probing aBR, NaBR, ISe, and affective/cognitive ToM. The results suggest that NaBR, which mainly relies on exteroceptive signals, predicts individual differences in cognitive ToM, possibly because it can allow differentiating between the self and others. Instead, the negative association between affective ToM and ISe suggests that an alteration of the internal body state representation (i.e., over-reporting interoceptive sensations) can affect emotional processing in social contexts. The finding that distinct aspects of the body processing from within (ISe) and from the outside (NaBR) differently contribute to ToM provides empirical support to the BR role in social cognition and can be relevant for developing interventions in clinical settings.

Questionnaires of interoception do not assess the same construct

There are a number of questionnaires assessing the self-reported trait-like aspect of interoception, also called interoceptive sensibility (ISb). Based on the varying purposes of their development and characteristics, however, it is not likely that they assess exactly the same construct. In a community sample of 265 adults, we examined this assumption for three commonly used questionnaires of ISb, namely the Body Awareness subscale of the Body Perception Questionnaire (BPQ-BA), the Body Awareness Questionnaire (BAQ), and the eight subscales of Multidimensional Assessment of Interoceptive Awareness (MAIA). We investigated their associations, and their relation to positive and negative affect and somatosensory amplification. According to the results of correlation analysis, BPQ-BA, BAQ and MAIA were partly unrelated to each other, partly showed weak to moderate positive associations. Also, differences with respect to their association with positive and negative affect were found. These findings suggest that the investigated questionnaires cannot be used interchangeably to assess the subjective aspect of interoception, and the term ISb is not appropriately defined.

Construct Validity of the Sensory Profile Interoception Scale: Measuring Sensory Processing in Everyday Life

Scholars and providers are coming to realize that one’s ability to notice and respond to internal body sensations (i.e., interoception) contributes to an overall sense of wellbeing. Research has demonstrated a relationship between interoceptive awareness and anxiety, for example. Currently, however, tools for evaluating one’s interoception lack the conceptual foundation and clarity necessary to identify everyday behaviors that specifically reflect interoceptive awareness. Unlike existing interoceptive measures, the Sensory Profile Interoception (SPI) scale is participation-based and grounded in Dunn’s Sensory Processing framework. In this study we investigated concurrent validity by correlating the SPI with the Adolescent/Adult Sensory Profile (A/ASP); we investigated construct validity by correlating the SPI with the Perth Alexithymia Scale (PAS), the Body Awareness Scale (BAS), and the State-Trait Anxiety Inventory (STAI). Using the REDCAP online platform, 74 college-aged participants completed the measures. Using Spearman rank order correlations there were statistically significant relationships between the corresponding sensory pattern subscales on SPI and A/ASP (r = 0.277 to r = 0.582). The PAS was only weakly related to the registration subscale of the SPI (r = 0.260). The BAS had significant relationships with seeking and avoiding on the SPI (r = 0.496 and r = 0.385). The STAI had significant relationships with sensitivity and registrations of the SPI (r = 0.266 and r = 0.361 for state; r = 0.403 and r = 0.321 for trait). Taken together, these findings provide evidence of construct validity of the SPI to identify participation patterns associated with both high and low interoception. With the more precise information the SPI provides, professionals can design tailored interventions to support everyday life goals and researchers can study interoception within authentic activities.