Contribution of Time Estimation and Knowledge to Heartbeat Counting Task Performance under Original and Adapted Instructions

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.

Exploring sex differences in cardiac interoceptive accuracy using the phase adjustment task

Previous evidence suggests males and females differ with respect to interoception-the processing of internal bodily signals-with males typically outperforming females on tasks of interoceptive accuracy. However, interpretation of existing evidence in the cardiac domain is hindered by the limitations of existing tools. In this investigation, we pooled data from several samples to examine sex differences in cardiac interoceptive accuracy on the phase adjustment task, a new measure that overcomes several limitations of the existing tools. In a sample of 266 individuals, we observed that females outperformed males, indicative of better cardiac interoceptive accuracy, but had lower confidence than males. These results held after controlling for sex differences in demographic, physiological and engagement factors. Importantly, these results were specific to the measure of cardiac interoceptive accuracy. No sex differences were observed for individuals who completed the structurally identical screener task, although a similar pattern of results was observed in relation to confidence. These surprising data suggest the presence of a female advantage for cardiac interoceptive accuracy and potential differences in interoceptive awareness (metacognition). Possible reasons for mixed results in the literature, as well as implications for theory and future research, are discussed.

Should Adolescents Listen to Their Hearts? A Closer Look at the Associations Between Interoception, Emotional Awareness and Emotion Regulation in Adolescents

The aim of the current study was to replicate findings from prior work among adults showing that individuals with better interoceptive skills have more emotional awareness, and show better emotion regulation abilities, in a sample of adolescents and by relying on instructions that reduce the contamination of known confound variables. A total of 102 Belgian adolescents (Mage = 14.10 years, SDage = .63; 50 males) completed self-report questionnaires of emotional processes (FEEL-KJ and DERS) and the modified heartbeat counting task. From this task, interoceptive accuracy, interoceptive sensibility (confidence ratings), and interoceptive awareness scores (within-person correlations) were derived per participant. Results revealed no associations between the three dimensions of interoception and adolescents' levels of emotional awareness, adaptive, and maladaptive emotion regulation. The lack of associations which contrast some prior work with adults may be due to developmental differences. However, these might also support the low validity of the heartbeat counting task, or could be attributed to the measurement of the emotion measures (i.e., self-report). Future studies should, nevertheless, also test whether these non-significant results can be explained by the developmental differences in adolescents. Longitudinal research is needed to capture interoceptive changes during adolescence, as well as to replicate the current findings using rigorous multimethod approaches that increase the validity of interoception measurement.

I can feel my heartbeat: The relationship between interoceptive abilities and emotional states during stress and recovery in healthy adolescents

The goal of the current study was to investigate the differential effects of three interoception dimensions on psychophysiological stress responses (reactivity and recovery) in adolescents. A total of 102 adolescents (Mage = 14.10 years, SDage = 0.63; 50 males) completed the heartbeat counting task with adapted instructions to assess interoceptive accuracy, sensibility, and awareness. During a follow-up session, participants underwent a standardized stressful task, throughout which measures of negative affect and respiratory sinus arrythmia (RSA) were collected. Results from multilevel models indicated that adolescents with higher interoceptive accuracy reported less pronounced increases in negative affect during stress induction, and subsequently experienced a less steep decrease in negative affect during recovery, compared to those with lower accuracy. Regarding RSA, adolescents with higher interoceptive accuracy exhibited greater decreases in RSA from baseline to stress, while those with higher interoceptive awareness maintained higher RSA levels throughout the experiment. In contrast, individuals with higher interoceptive sensibility exhibited lower levels of RSA during the experiment. These findings add to the limited literature on interoception in adolescents by illuminating its role in emotional experiences, stress responses, and recovery processes. Our study suggests that examining distinct dimensions of interoception, along with physiological measures during stress and recovery, is crucial for understanding its beneficial or adverse effects in adolescence. The complexity and potential significance of interoceptive dimensions extend beyond their correlations with traditional self-report measures, warranting further investigation to clarify their implications and underlying mechanisms.

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.

Heart rate and insula activity increase in response to music in individuals with high interoceptive sensitivity

Interoception plays an important role in emotion processing. However, the neurobiological substrates of the relationship between visceral responses and emotional experiences remain unclear. In the present study, we measured interoceptive sensitivity using the heartbeat discrimination task and investigated the effects of individual differences in interoceptive sensitivity on changes in pulse rate and insula activity in response to subjective emotional intensity. We found a positive correlation between heart rate and valence level when listening to music only in the high interoceptive sensitivity group. The valence level was also positively correlated with music-elicited anterior insula activity. Furthermore, a region of interest analysis of insula subregions revealed significant activity in the left dorsal dysgranular insula for individuals with high interoceptive sensitivity relative to individuals with low interoceptive sensitivity while listening to the high-valence music pieces. Our results suggest that individuals with high interoceptive sensitivity use their physiological responses to assess their emotional level when listening to music. In addition, insula activity may reflect the use of interoceptive signals to estimate emotions.

Blind individuals' enhanced ability to sense their own heartbeat is related to the thickness of their occipital cortex

Blindness is associated with heightened sensory abilities, such as improved hearing and tactile acuity. Moreover, recent evidence suggests that blind individuals are better than sighted individuals at perceiving their own heartbeat, suggesting enhanced interoceptive accuracy. Structural changes in the occipital cortex have been hypothesized as the basis of these behavioral enhancements. Indeed, several studies have shown that congenitally blind individuals have increased cortical thickness within occipital areas compared to sighted individuals, but how these structural differences relate to behavioral enhancements is unclear. This study investigated the relationship between cardiac interoceptive accuracy and cortical thickness in 23 congenitally blind individuals and 23 matched sighted controls. Our results show a significant positive correlation between performance in a heartbeat counting task and cortical thickness only in the blind group, indicating a connection between structural changes in occipital areas and blind individuals' enhanced ability to perceive heartbeats.

Intranasal Oxytocin Improves Interoceptive Accuracy and Heartbeat-Evoked Potentials During a Cardiac Interoceptive Task

BACKGROUND

Interoception represents perception of the internal bodily state, which is closely associated with social/emotional processing and physical health in humans. Understanding the mechanism that underlies interoceptive processing, particularly its modulation, is therefore of great importance. Given the overlap between oxytocinergic pathways and interoceptive signaling substrates in both peripheral visceral organs and the brain, intranasal oxytocin administration is a promising approach for modulating interoceptive processing.

METHODS

Using a double-blind, placebo-controlled, between-participant design, we recruited 72 healthy male participants who performed a cardiac interoceptive task during electroencephalograph and electrocardiograph recording to examine whether intranasal administration of the neuropeptide oxytocin could modulate interoceptive processing. We also collected data in a resting state to examine whether we could replicate previous findings.

RESULTS

The results showed that in the interoceptive task, oxytocin increased interoceptive accuracy at the behavioral level, which was paralleled by larger heartbeat-evoked potential amplitudes in frontocentral and central regions on the neural level. However, there were no significant effects of oxytocin on electroencephalograph or electrocardiograph during resting state.

CONCLUSIONS

These findings suggest that oxytocin may only have a facilitatory effect on interoceptive processing under task-based conditions. Our findings not only provide new insights into the modulation of interoceptive processing via targeting the oxytocinergic system but also provide proof-of-concept evidence for the therapeutic potential of intranasal oxytocin in mental disorders with dysfunctional interoception.

Disrupted interoceptive awareness by auditory distractor: Difficulty inferring the internal bodily states?

Recent studies have associated interoceptive awareness, the perception of internal bodily sensations, with a predictive mechanism of perception across all sensory modalities. According to the framework, volitional attention plays a pivotal role in interoceptive awareness by prioritizing interoceptive sensations over exteroceptive ones. Consequently, it is hypothesized that the presence of irrelevant stimuli would disrupt the attentional modulation and interoceptive awareness, which remains untested. In this study, we investigated if interoceptive awareness is diminished by unrelated auditory distractors to validate the proposed perceptual framework. A total of 30 healthy human volunteers performed the heartbeat counting task both with and without auditory distractors. Additionally, we measured participant's psychophysiological traits related to interoception, including the high-frequency component of heart rate variability (HF-HRV) and trait interoceptive sensibility. The results showed that interoceptive accuracy, confidence, and heartbeat intensity decreased in the presence of distractor sound. Moreover, individuals with higher HF-HRV and a greater tendency to worry about bodily states experienced a more pronounced distractor effect on interoceptive awareness. These results provide support for the perceptual mechanism of interoceptive awareness in terms of the predictive process, highlighting the impact of relative precision across interoceptive and exteroceptive signals on perceptual experiences.

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.

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

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

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.

Recognition of others' interoceptive states in those with and without eating disorders

BACKGROUND

The ability to recognize one's own emotions is associated with one's ability to recognize others' emotions. Beyond the domain of emotion, however, the relationship between recognition of one's own internal states (interoception) and others' interoceptive states has not been investigated, either in the typical population or clinical groups with interoceptive difficulties (e.g. eating disorders; EDs).

METHOD

This study investigated recognition of one's own and others' internal states in adults with and without eating disorders, using a high frequency visual noise paradigm. Participants completed self-report measures of interoception, alexithymia (difficulties recognising one's own emotional internal states) and ED symptomatology, and the Heartbeat Counting Task measure of cardiac interoceptive accuracy.

RESULTS

Alexithymia was significantly negatively correlated with recognition of others' interoceptive states. EDs were not associated with difficulties recognising others' interoceptive states.

CONCLUSIONS

The ability to recognise one's own emotional internal states is associated with the recognition of others' interoceptive states, which may contribute to social skills and the ability to care for others.

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.

The misjudgment of interoceptive awareness: Systematic overrating of interoceptive awareness among individuals with lower interoceptive metacognitive skills

Knowing when perceiving inner bodily signals better and when perceiving them worse is a health relevant but understudied dimension of interoception. Therefore, the present study assessed interoceptive metacognition (IMC) as the skill to adequately monitor interoceptive accuracy in the cardiac domain. We used the Graz Ambulatory Interoception task (GRAIT), which applied two intervals of the heartbeat tracking task 12 times a day for 3 days in total to n = 66 participants. We assessed IMC as the relative correspondence between interoceptive accuracy and the subjective confidence ratings. We found that 6 % of the total IMC variance was due to person, which was assessed reliable (RKRn=0.81). Furthermore, the between-person variation of IMC was negatively associated with the MAIA (especially attention regulation and self-regulation). People who believe that they are aware of their interoceptive experiences (MAIA) showed lower IMC. This study advocates the assessment of interoception in everyday life.

"Listen to your heart": A novel interoceptive strategy for real-time fMRI neurofeedback training of anterior insula activity

Real-time fMRI (rt-fMRI) neurofeedback (NF) training is a novel non-invasive technique for volitional brain modulation. Given the important role of the anterior insula (AI) in human cognitive and affective processes, it has become one of the most investigated regions in rt-fMRI studies. Most rt-fMRI insula studies employed emotional recall/imagery as the regulation strategy, which may be less effective for psychiatric disorders characterized by altered emotional processing. The present study thus aimed to examine the feasibility of a novel interoceptive strategy based on heartbeat detection in rt-fMRI guided AI regulation and its associated behavioral changes using a randomized double-blind, sham feedback-controlled between-subject design. 66 participants were recruited and randomly assigned to receive either NF from the left AI (LAI) or sham feedback from a control region while using the interoceptive strategy. N = 57 participants were included in the final data analyses. Empathic and interoceptive pre-post training changes were collected as behavioral measures of NF training effects. Results showed that participants in the NF group exhibited stronger LAI activity than the control group with LAI activity being positively correlated with interoceptive accuracy following NF training, although there were no significant increases of LAI activity over training sessions. Importantly, ability of LAI regulation could be maintained in a transfer session without feedback. Successful LAI regulation was associated with strengthened functional connectivity of the LAI with cognitive control, memory and learning, and salience/interoceptive networks. The present study demonstrated for the first time the efficacy of a novel regulation strategy based on interoceptive processing in up-regulating LAI activity. Our findings also provide proof of concept for the translational potential of this strategy in rt-fMRI AI regulation of psychiatric disorders characterized by altered emotional processing.

Interoception and the musical brain: Evidence from cross-sectional and longitudinal behavioral and resting-state fMRI study

Musical training has been linked to enhanced interoceptive abilities and increased resting-state (RS) functional connectivity (FC) within the interoceptive brain network. We aimed to replicate and extend these findings with a unique cross-sectional and longitudinal study design. Professional musicians and matched individuals with no prior musical experience (training group) were recruited. Participants underwent RS fMRI scans and completed heartbeat counting and discrimination tasks outside of the scanner (time point 1). The training group additionally had RS scans and interoception tests repeated after a 6-month-long keyboard course training (time point 2). We found no evidence for increased interoceptive abilities in professional musicians relative to non-musicians, nor did we observe any improvements in interoception over the course of musical training. RS FC analysis revealed increased FC within the sensorimotor network in professional musicians compared to the training group at the first time point with no change in FC over time in the Training group. These findings challenge the view that musical training may improve interoceptive abilities. Yet, the results suggest that musical training is related to increased communication within the sensorimotor RS network, which consists of some hubs important for interoceptive processing (namely pre- and postcentral gyri and supplementary motor area).

Is that My Heartbeat? Measuring and Understanding Modality-Dependent Cardiac Interoception in Virtual Reality

Measuring interoception ('perceiving internal bodily states') has diagnostic and wellbeing implications. Since heartbeats are distinct and frequent, various methods aim at measuring cardiac interoceptive accuracy (CIAcc). However, the role of exteroceptive modalities for representing heart rate (HR) across screen-based and Virtual Reality (VR) environments remains unclear. Using a PolarH10 HR monitor, we develop a modality-dependent cardiac recognition task that modifies displayed HR. In a mixed-factorial design (N=50), we investigate how task environment (Screen, VR), modality (Audio, Visual, Audio-Visual), and real-time HR modifications (±15%, ±30%, None) influence CIAcc, interoceptive awareness, mind-body measures, VR presence, and post-experience responses. Findings showed that participants confused their HR with underestimates up to 30%; environment did not affect CIAcc but influenced mind-related measures; modality did not influence CIAcc, however including audio increased interoceptive awareness; and VR presence inversely correlated with CIAcc. We contribute a lightweight and extensible cardiac interoception measurement method, and implications for biofeedback displays.

Increasing familiarity with the heartbeat counting task does not affect performance

BACKGROUND

Interoception is typically defined as the processing and perception of internal signals. A common evaluation of interoceptive abilities is the heartbeat counting task, during which participants count their heartbeats over a period of time. It has been argued recently, however, that performance in this task may reflect processes other than cardiac sensation.

OBJECTIVE

This study aimed to: 1) observe heartbeat counting task performance changes across multiple repetitions of the task; and 2) compare performance in the heartbeat counting task with that for a visual counting task to investigate generalised propensities for how uncertain stimuli are reported.

METHODS

Seventy-nine healthy participants performed seven blocks each of the heartbeat and visual counting tasks. Scores for each of the tasks were compared across blocks to identify any change in performance. Performance in the two tasks was then correlated. The study was preregistered at https://doi.org/10.17605/OSF.IO/GWAB7.

RESULTS

Heartbeat counting task performance did not change over blocks. In contrast, scores for the visual counting task reduced over time. A positive correlation was seen between performance in the two tasks (ρ(79) = .27).

CONCLUSION

Heartbeat counting task performance is stable across repetitions of the task, not changing with increasing familiarity. This suggests that non-interoceptive factors, such as beliefs, may be involved. The correlation between the heartbeat and visual counting tasks may point to a general propensity in counting uncertain stimuli across sensory domains. Together, these results raise questions about the interpretation of the heartbeat counting task as a measure of interoception.

Mental health meets computational neuroscience: A predictive Bayesian account of the relationship between interoception and multisensory bodily illusions in anorexia nervosa

Mental health disorders pose a significant challenge to society. The Bayesian perspective on the mind offers unique insights and tools that may help address a variety of mental health conditions. Psychopathological dysfunctions are often connected to altered predictive and active inference processes, in which cognitive and physiological pathogenic beliefs shape the clinical condition and its symptoms. However, there is a lack of general empirical models that integrate cognitive beliefs, physiological experience, and symptoms in healthy and clinical populations. In this study, we examined the relationship between altered predictive mechanisms, interoception, and pathological bodily distortions in healty individuals and in individuals suffering from anorexia nervosa (AN). AN patients (N=15) completed a Virtual Reality Full-Body Illusion along with interoceptive tasks twice: at hospital admission during an acute symptomatological phase (Time 1) and after a 12-week outpatient clinical weight-restoring rehabilitative program (Time 2). Results were compared to a healthy control group. Our findings indicated that higher levels of interoceptive metacognitive awareness were associated with a greater embodiment. However, unlike in healthy participants, AN patients' interoceptive metacognition was linked to embodiment even in multisensory mismatching (asynchronous) conditions. In addition, unlike in healthy participants, higher interoceptive metacognition in AN patients was related to prior abnormal bodily distortions during the acute symptomatology phase. Prediction errors in bodily estimates predicted posterior bodily estimate distortions after the illusion, but while this relationship was only significant in the synchronous condition in healthy participants, there was no significant difference between synchronous and asynchronous conditions in AN patients. Despite the success of the rehabilitation program in restoring some dysfunctional patterns in the AN group, prediction errors and posterior estimate distortions were present at hospital discharge. Our findings suggest that individuals with AN prioritize interoceptive metacognitive processes (i.e., confidence in their own perceived sensations rather than their actual perceptions), disregarding bottom-up bodily inputs in favour of their prior altered top-down beliefs. Moreover, even if the rehabilitative program partially mitigated these alterations, the pathological condition impaired the patients' ability to coherently update their prior erroneous expectations with real-time multisensory bottom-up bodily information, possibly locking the patients in the experience of a distorted prior top-down belief. These results suggest new therapeutic perspectives and introduce the framework of regenerative virtual therapy (RVT), which aims at utilizing technology-based somatic modification techniques to restructure the maladaptive priors underlying a pathological condition.

Dynamic heartbeat tracking beyond the laboratory: Introducing the novel Graz Ambulatory Interoception Task (GRAIT)

We present a novel ambulatory method, the Graz Ambulatory Interoception Task (GRAIT), to assess the accuracy of interoceptive beliefs (AccIB). This method captures both between- and within-person variations of AccIB by having participants counting perceived heartbeats in daily life. Reliability analyses showed high between-person (RkR = 0.99) and moderate within-person reliability (RCn = 0.62). Validity was supported by associations with an established laboratory task (r = 0.87). Within-person associations revealed that interoceptive sensibility, heart rate variability, and states of low arousal coupled with positive affect were linked to AccIB. Study 2 replicated these findings and showed a relationship between AccIB and self-control in everyday life, highlighting the importance of cardiac interoception and its relevance for health.

Mind your heart to bear the weight: Cardiac interoception predicts action-related visual perception when wearing a heavy backpack

Visual perception can be modulated by the physiological potential for action. For instance, it was famously shown that a geographical slant appears steeper when wearing a heavy backpack than not wearing any. However, those results are not always replicated. In the present exploratory study, we test the hypothesis that the backpack weight's effect on perception relies on the ability of the cognitive system to integrate the physiological constraint's change rather than the change itself. Young adults (n = 54) wore an electrocardiogram monitor and completed a computerised task in which photographs of real geographical slants were displayed on a screen while wearing a heavy versus light backpack. The activity of the vagus nerve, as an index of physiological adaptability, was recorded as a proxy of the physiological state during the task. The participants also completed an interoception task assessing one's ability to detect his or her own heartbeat as the index of integration ability of the cognitive system. While Bayesian analyses revealed no difference in angle estimation between carrying a heavy versus light backpack, the results indicated that interoception predicted less accurate angle estimation only when wearing a heavy backpack. In contrast, there was anecdotal evidence that vagal activity changes predicted visual perception. Interoception might thus play a crucial role in the interplay between the physiological potential for action and action-related visual perception.

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.

Interoception in functional motor symptoms and functional seizures: Preliminary evidence of intact accuracy alongside reduced insight and altered sensibility

Altered interoception may be a pathophysiological mechanism in functional neurological disorder (FND). However, findings have been inconsistent across interoceptive dimensions in FND including functional motor symptoms (FMS) and seizures (FS). Here, individuals with FMS/FS (n = 17) and healthy controls (HC, n = 17) completed measures of interoceptive accuracy and insight (adapted heartbeat tracking task [HTT] with confidence ratings), a time estimation control task (TET) and the Multidimensional Assessment of Interoceptive Awareness-2 (MAIA-2) to assess interoceptive sensibility. The groups did not differ in interoceptive accuracy (p = 1.00, g = 0.00) or confidence (p = .99, g = 0.004), although the FMS/FS group displayed lower scores on the "Not-Distracting" (p < .001, g = 1.42) and "Trusting" (p = .005, g = 1.17) MAIA-2 subscales, relative to HCs. The groups did not differ in TET performance (p = .82, g = 0.08). There was a positive relationship between HTT accuracy and confidence (insight) in HCs (r = .61, p = .016) but not in FMS/FS (r = 0.11, p = .69). HTT confidence was positively correlated with MAIA-2 "Self-Regulation" (r = 0.77, p = .002) and negatively correlated with FND symptom severity (r = -0.84, p < .001) and impact (r = -0.86, p < .001) in FMS/FS. Impaired interoceptive accuracy may not be a core feature in FMS/FS, but reduced insight and altered sensibility may be relevant. Reduced certainty in self-evaluations of bodily experiences may contribute to the pathogenesis of FND symptoms.

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.

The impact of interoceptive accuracy and stimulation type on the out-of-body experience

People tend to perceive a virtual body standing in front of them as their own if it is either stroked or moving synchronously with their own real body-the out-of-body experience (OBE). We combined synchrony manipulation with two other factors of theoretical interest: the kind of stimulation, visuotactile stimuli or visuomotor correlations, being synchronised and the interoceptive accuracy (IA) of participants, assessed by means of the heartbeat counting task. Results showed that explicit measures of embodiment were systematically affected by synchrony, and this synchrony effect was more pronounced for visuomotor than for visuotactile conditions. The walking drift was affected by IA: In visuotactile conditions, the synchrony effect was pronounced in individuals with low IA, presumably reflecting a stronger impact of the visual information. In visuomotor conditions, however, the synchrony effect was stronger in individuals with high IA, presumably reflecting a stronger impact of re-afferent information generated by the participants' own movements.

Reduced Interoception Abilities in Patients with Restless Legs Syndrome

Background

Restless legs syndrome (RLS) is a complex sensorimotor disorder occurring with a typical circadian fashion. Association with additional features, like alexithymia and nocturnal compulsive behaviors further complicates the framework.

Objectives

To assess interoception in RLS.

Methods

A total of 25 RLS patients and 28 controls underwent the heartbeat tracking task (interoceptive accuracy [IAC]). RLS symptoms' frequency, disturbance and duration, nocturnal behaviors, interoceptive awareness (IAW), alexithymia, depressive and anxiety symptoms were also collected.

Results

RLS patients showed significant lower IAC (P = 0.0003) and IAW (P = 0.012), and reported more nocturnal eating behaviors (P < 0.001). IAC positively correlated with IAW (R = 0.32), and negatively correlated with age (R = -0.58). Nocturnal eating behavior negatively correlated with IAC (R = -0.44) and IAW (R = -0.50).

Conclusions

RLS patients presented reduced interoceptive abilities correlating with higher nocturnal eating behaviors. Future studies are needed to explore the role of interoception in RLS pathophysiology, also in relation to other sensorimotor aspects.

Interoceptive abilities facilitate taking another's spatial perspective

Information can be perceived from a multiplicity of spatial perspectives, which is central to effectively understanding and interacting with our environment and other people. Interoception, the sense of the physiological state of our body, is also a fundamental component contributing to our perception. However, whether the perception of our inner body signals influences our ability to adopt and flexibly change between different spatial perspectives remains poorly understood. To investigate this, 90 participants completed tasks assessing multiple dimensions of interoception (interoceptive sensibility, cardiac interoceptive accuracy and awareness) and the Graphesthesia task to assess tactile spatial perspective-taking and its flexibility. The results revealed that higher cardiac interoceptive awareness is associated with greater consistency in adopting a perspective decentred from the self. Second, higher cardiac interoceptive accuracy was associated with slower and less accurate performance in switching from a decentred to an egocentred perspective. These results show that interoceptive abilities facilitate decentred spatial perspective-taking, likely reflecting stronger perceived boundaries between internal states and the external world.

Interoception Within the Context of Impulsivity and Addiction

Purpose of Review

The goal of this review is to examine the relationship between impulsivity and interoception in addiction, to summarize the current understanding of the topic, identify any gaps in knowledge, and provide directions for future research.

Research Findings

Interoception may be a contributing factor to impulsive behaviour and, thus, addiction. Substance abuse can negatively impact the brain's ability to process interoceptive information and impact the reward system, leading to decreased sensitivity to natural rewards and increased sensitivity to drugs. There is potential for new therapies, such as mindfulness, interoceptive training, brain stimulation, or vagal nerve stimulation to target both impulsivity and interoception in the treatment of addiction.

Summary

Despite a growing interest in interoception in addiction research, further research is needed to better understand the role of interoception in addiction and to develop new methods for studying how individuals with addiction process and perceive internal bodily sensations.

Interoceptive accuracy is associated with benefits in decision making in children

Introduction

Decision making results not only from logical analyses, but seems to be further guided by the ability to perceive somatic information (interoceptive accuracy). Relations between interoceptive accuracy and decision making have been exclusively studied in adults and with regard to complex, uncertain situations (as measured by the Iowa Gambling Task, IGT).

Methods

In the present study, 1454 children (6-11 years) were examined at two time points (approximately 1 year apart) using an IGT as well as a delay-of-gratification task for sweets-items and toy-items. Interoceptive accuracy was measured using a child-adapted version of the Heartbeat Perception Task.

Results

The present results revealed that children with higher, as compared to lower, interoceptive accuracy showed more advantageous choices in the IGT and delayed more sweets-items, but not toy-items, in a delay-of-gratification task at time point 2 but not at time point 1. However, no longitudinal relation between interoceptive accuracy and decision making 1 year later could be shown.

Discussion

Results indicate that interoceptive accuracy relates to decision-making abilities in situations of varying complexity already in middle childhood, and that this link might consolidate across the examined 1-year period. Furthermore, the association of interoceptive accuracy and the delay of sweets-items might have implications for the regulation of body weight at a later age.

Effects of interoceptive accuracy on timing control in the synchronization tapping task

Humans often perform rhythmic synchronized movements. Professional musicians and dancers particularly perform such movement tasks well and have a higher interoceptive accuracy (IAcc) than non-musicians and non-dancers. We thus hypothesized that rhythmic synchronized movements might be enhanced by a higher IAcc. To investigate this hypothesis, this study conducted a heartbeat counting task and a rhythmic synchronization tapping task with normal (easier) and slow (harder) tempi metronomes. Inconsistent with our hypothesis, however, a higher IAcc was negatively correlated with timing control, but only in the slow tempo condition [r (30) = 0.46, p < 0.05]. This suggests that a higher IAcc did not enhance timing control in rhythmic synchronized movements but rather weakened it, resting heart rate variability was not correlated with timing control.

Seeing Through Each Other's Hearts: Inferring Others' Heart Rate as a Function of Own Heart Rate Perception and Perceived Social Intelligence

Successful social interactions require a good understanding of the emotional states of other people. This information is often not directly communicated but must be inferred. As all emotional experiences are also imbedded in the visceral or interoceptive state of the body (i.e., accelerating heart rate during arousal), successfully inferring the interoceptive states of others may open a window into their emotional state. But how well can people do that? Here, we replicate recent results showing that people can discriminate between the cardiac states (i.e., the resting heartrate) of other people by simply looking at them. We further tested whether the ability to infer the interoceptive states of others depends on one's own interoceptive abilities. We measured people's performance in a cardioception task and their self-reported interoceptive accuracy. Whilst neither was directly associated to their ability to infer the heartrate of another person, we found a significant interaction. Specifically, overestimating one's own interoceptive capacities was associated with a worse performance at inferring the heartrate of others. In contrast, underestimating one's own interoceptive capacities did not have such influence. This pattern suggests that deficient beliefs about own interoceptive capacities can have detrimental effects on inferring the interoceptive states of other people.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42761-022-00151-4.

Confounding effects of heart rate, breathing rate, and frontal fNIRS on interoception

Recent studies have established that cardiac and respiratory phases can modulate perception and related neural dynamics. While heart rate and respiratory sinus arrhythmia possibly affect interoception biomarkers, such as heartbeat-evoked potentials, the relative changes in heart rate and cardiorespiratory dynamics in interoceptive processes have not yet been investigated. In this study, we investigated the variation in heart and breathing rates, as well as higher functional dynamics including cardiorespiratory correlation and frontal hemodynamics measured with fNIRS, during a heartbeat counting task. To further investigate the functional physiology linked to changes in vagal activity caused by specific breathing rates, we performed the heartbeat counting task together with a controlled breathing rate task. The results demonstrate that focusing on heartbeats decreases breathing and heart rates in comparison, which may be part of the physiological mechanisms related to "listening" to the heart, the focus of attention, and self-awareness. Focusing on heartbeats was also observed to increase frontal connectivity, supporting the role of frontal structures in the neural monitoring of visceral inputs. However, cardiorespiratory correlation is affected by both heartbeats counting and controlled breathing tasks. Based on these results, we concluded that variations in heart and breathing rates are confounding factors in the assessment of interoceptive abilities and relative fluctuations in breathing and heart rates should be considered to be a mode of covariate measurement of interoceptive processes.

Interoceptive accuracy correlates with precision of time perception in the millisecond range

It has been proposed that accuracy in time perception is related to interoceptive accuracy and vagal activity. However, studies investigating time perception in the supra-second range have provided mixed results, and few studies have investigated the sub-second range. Moreover, there is a lack of studies investigating the relationship between precision in time perception and interoceptive accuracy. A recent meta-analytic review of neuroimaging studies proposed a dynamic interaction between two types of timing processing-an endogenous time keeping mechanism and the use of exogenous temporal cues. Interoceptive accuracy may affect both accuracy and precision of primary temporal representations, as they are generated based on the endogenous time keeping mechanism. Temporal accuracy may vary when adapted to the environmental context. In contrast, temporal precision contains some constant noise, which may maintain the relationship with interoceptive accuracy. Based on these assumptions, we hypothesized that interoceptive accuracy would be associated with temporal precision in the sub-second range, while vagal activity would be associated with temporal accuracy. We used the temporal generalization task, which allowed us to calculate the indices of temporal accuracy and temporal precision in line with the existing research, and also compute the index of participants' sensitivity according to the signal detection theory. Specifically, we investigated whether (1) interoceptive accuracy would correlate with temporal accuracy, temporal precision, or sensitivity and (2) resting-state vagal activity would correlate with temporal accuracy, temporal precision, or sensitivity. The results indicated that interoceptive accuracy was positively correlated with temporal precision as well as sensitivity, but not with temporal accuracy, in the sub-second range time perception. Vagal activity was negatively correlated only with sensitivity. Furthermore, we found a moderation effect of sensitivity on the relationship between vagal activity and perceived duration, which affected the association between vagal activity and temporal accuracy. These findings suggest the importance of precision as an aspect of time perception, which future studies should further explore in relation to interoception and vagal activity, and of the moderation effects of factors such as participants' sensitivity in this context.

Anterior Insula Activation During Cardiac Interoception Relates to Depressive Symptom Severity in HIV-Positive and HIV-Negative Postmenopausal Women

OBJECTIVE

This study aimed to determine whether subclinical symptoms of depression in postmenopausal women are associated with blood oxygen level-dependent (BOLD) activity within the anterior insula during cardiac interoceptive awareness and whether this association differs for persons living with the human immunodeficiency virus (PWH).

METHOD

Twenty-three postmenopausal (mean [standard deviation] age = 56.5 [4.8] years) and 27 HIV-negative women (mean [standard deviation] age = 56.4 [8.0]) underwent functional magnetic resonance imaging while performing a heartbeat detection task. BOLD activation within the bilateral anterior insula based on the contrast of a heartbeat detection condition with and without a distracting tone was entered along with age, HIV status, and psychological stress into two multivariate regression models with self-reported depressive symptom severity as the outcome.

RESULTS

Depressive symptoms did not vary by HIV status, nor was there a main effect or interaction for PWH on insula BOLD activation. Depressive symptoms were positively associated with psychological stress for the left ( β = 0.310, t (49) = 2.352, p = .023) and right brain models ( β = 0.296, t (49) = 2.265, p = .028) as well as the magnitude of BOLD activation in the left insula ( β = 0.290, t (49) = 2.218, p = .032) and right insula ( β = 0.318, t (49) = 2.453, p = .018), respectively. Exploratory analyses revealed that greater magnitude of BOLD activation attributed to exteroceptive noise (tone) was also correlated with self-reported distrust and preoccupation with interoceptive sensations.

CONCLUSIONS

Results support an active interference model for interoceptive awareness wherein greater BOLD signal in the anterior insula in the presence of distracting exteroceptive stimuli may reflect greater prediction error, a feature of depression.

Embodied feelings-A meta-analysis on the relation of emotion intensity perception and interoceptive accuracy

Emotion theories emphasize the relevance of (predicted) bodily changes for the construction of one's own emotions and an extensive overlap of brain regions involved during emotion intensity perception and somatosensory processing. The ability to accurately perceive bodily changes and its impact on the perception of emotion intensity has been studied for at least 40 years. The results of previous studies were summarized in a meta-analysis to examine how closely interoceptive accuracy and emotion intensity are related. After a systematic literature search, 4036 studies were screened for eligibility. Only studies assessing adults from general population samples were considered. Samples recruited to examine mental disorders or neurological conditions were excluded. Thirty studies with a quantifiable measure for the relation of interoceptive accuracy and emotion intensity perception were included in the meta-analysis. Interoceptive accuracy was significantly related with emotion intensity perception, when emotions were experimentally induced (k= 22, r= 0.15). However, the relationship was only found when IAPS images (k= 9, r= 0.33) or facial expressions (k= 3, r= 0.24) were used for emotion induction. No significant relation was found in studies without emotion induction (k= 19, r = -0.007). There was considerable bias, varying dependent on bias assessment method, study protocol and examined risk of bias dimension. We discuss the impact of differences in study protocols, review the operationalization of interoceptive accuracy critically and derive directions for future research.

What counts when heartbeats are counted

Schandry's mental heartbeat tracking task is a widely used measure of interoception, assessing heartbeat perception. We classify the factors that contribute to performance on the task as (i) trait-like characteristics, (ii) expectation-related factors, and (iii) factors showing participants' task set. We recommend conducting further research to better understand what exactly the task measures.

Interindividual differences in interoception modulate behavior and brain responses in emotional inference

Emotional experiences are proposed to arise from contextualized perception of bodily responses, also referred to as interoceptive inferences. The recognition of emotions benefits from adequate access to one's own interoceptive information. However, direct empirical evidence of interoceptive inferences and their neural basis is still lacking. In the present fMRI study healthy volunteers performed a probabilistic emotion classification task with videotaped dynamically unfolding facial expressions. In a first step, we aimed to determine functional areas involved in the processing of dynamically unfolding emotional expressions. We then tested whether individuals with higher interoceptive accuracy (IAcc), as assessed by the Heartbeat detection task (HDT), or higher interoceptive sensitivity (IS), as assessed by the Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), benefit more from the contextually given likelihood of emotional valence and whether brain regions reflecting individual IAcc and/or IS play a role in this. Individuals with higher IS benefitted more from the biased probability of emotional valence. Brain responses to more predictable emotions elicited a bilateral activity pattern comprising the inferior frontal gyrus and the posterior insula. Importantly, individual IAcc scores positively covaried with brain responses to more surprising and less predictable emotional expressions in the insula and caudate nucleus. We show for the first time that IAcc score is associated with enhanced processing of interoceptive prediction errors, particularly in the anterior insula. A higher IS score seems more likely to be associated with a stronger weighting of attention to interoceptive changes processed by the posterior insula and ventral prefrontal cortex.

Interoception as independent cardiac, thermosensory, nociceptive, and affective touch perceptual submodalities

Interoception includes signals from inner organs and thin afferents in the skin, providing information about the body's physiological state. However, the functional relationships between interoceptive submodalities are unclear, and thermosensation as skin-based interoception has rarely been considered. We used five tasks to examine the relationships among cardiac awareness, thermosensation, affective touch, and nociception. Thermosensation was probed with a classic temperature detection task and the new dynamic thermal matching task, where participants matched perceived moving thermal stimuli in a range of colder/warmer stimuli around thermoneutrality. We also examined differences between hairy and non-hairy skin and found superior perception of dynamic temperature and static cooling on hairy skin. Notably, no significant correlations were observed across interoceptive submodality accuracies (except for cold and pain perception in the palm), which indicates that interoception at perceptual levels should be conceptualised as a set of relatively independent processes and abilities rather than a single construct. DATA AVAILABILITY STATEMENT: Data of this study are available as a supplementary file.

Relationship of Interoceptive Accuracy With Risky Decision-Making and Treatment Outcomes in Male Patients With Alcohol Use Disorder

Abstract. Lower levels of interoceptive awareness (IA) may be present in individuals with substance use disorder (SUD), and damage to related brain regions caused by substance use may disrupt IA. Disturbance in the bodily feedback system may fail to engage in effective decision-making. This study focused on the premise that interoceptive accuracy (IAc), as the primary construct of IA, is implicated in SUD and that poor IAc is linked to risky decision-making and adversely affects treatment outcomes. Eighty-five patients with alcohol use disorder (AUD) (current severity: moderate or severe) and 87 healthy control subjects were enrolled in the present study. All participants performed the heart rate tracking task and a computerized version of the Iowa gambling task (IGT). Characteristics of patients’ addiction profiles were assessed with the Addiction Profile Index (API) Clinical Form. IAc and IGT scores of patients with AUD were lower than healthy controls. IGT scores of patients with low IAc were lower than those of patients with high IAc and decreased IAc is predictive of decreased IGT scores. No significant differences were determined in treatment outcomes at 3, 6, and 12 months after hospitalization between the low-IAc and high-IAc patient groups. Our results suggest that IAc is implicated in AUD and that poor IAc is predictive of increased risky decision-making. Risky decision-making that results in substance use may be partly related to a deficit in the interoceptive ability to guide behavior. Focus on IAc without reference to complex clinical case presentations in AUD makes it difficult to draw any definitive conclusions about the role of IAc in clinical outcomes.

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

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

The Cardiac Timing Toolbox (CaTT): Testing for physiologically plausible effects of cardiac timing on behaviour

There is a long history of, and renewed interest in, cardiac timing effects on behaviour and cognition. Cardiac timing effects may be identified by expressing events as a function of their location in the cardiac cycle, and applying circular (i.e. directional) statistics to test cardiac time-behaviour associations. Typically this approach 'stretches' all points in the cardiac cycle equally, but this is not necessarily physiologically valid. Moreover, many tests impose distributional assumptions that are not met by such data. We present a set of statistical techniques robust to this, instantiated within our new Cardiac Timing Toolbox (CaTT) for MATLAB: A physiologically-motivated method of wrapping behaviour to the cardiac cycle; and a set of non-parametric statistical tests that control for common confounds and distributional characteristics of these data. Using a reanalysis of previously published data, we guide readers through analyses using CaTT, aiding researchers in identifying physiologically plausible associations between heart-timing and cognition.

Decision-making, interoceptive awareness and mindful attention awareness in male patients with alcohol use disorder

INTRODUCTION

Decision-making deficits in individuals with alcohol use disorder (AUD) may be partly related to their decreased interoceptive awareness (IA), which is associated with some aspects of mindfulness.

METHODS

52 abstinent male inpatients with AUD (current severity: moderate or severe) and 52 healthy male volunteers performed the heart rate tracking task and a computerised version of the Iowa gambling task (IGT). Trait mindfulness was evaluated with the mindful attention awareness scale (MAAS).

RESULTS

Heartbeat perception (HBP), MAAS, and IGT scores of patients with AUD were significantly lower than those of healthy controls. The difference between groups with respect to IGT scores did not remain significant after controlling for the covariates, and HBP scores were linked significantly to the subjects' IGT performance. HBP scores significantly predicted IGT scores of both the overall sample and patients. MAAS scores did not correlate significantly with HBP and IGT scores in either the patient or control group.

CONCLUSION

It is possible that IA plays a role in decision-making and decreased interoceptive accuracy is a predictor of impaired decision-making in individuals with AUD. More empirical data are needed to develop a better insight into the relationship between IA and multi-dimensional nature of mindfulness.

Interoception and social cognition in chronic low back pain: a common inference disturbance? An exploratory study

Aim: Lower interoceptive abilities are a characteristic of chronic pain conditions. Social support plays an important role in chronic low back pain (cLBP) but social cognitive skills have rarely been investigated. This study aimed to characterize interoceptive and social cognitive abilities in cLBP and to study the relationship between both domains that have been brought closer together by brain predictive coding models. Materials & methods: Twenty-eight patients with cLBP and 74 matched controls were included. Interoceptive accuracy (Heart Beat Perception Task), sensibility/awareness (Multidimensional Assessment of Interoceptive Awareness) and mental-states inference abilities (Mini-Social Cognition and Emotional Assessment) were assessed. Results: cLBP Patients had lower interoceptive accuracy and mentalizing performance. Conclusion: Less efficient interoceptive accuracy and mentalizing abilities were found in cLBP patients without correlation between these performances.