Investigating interoception and body awareness in adults with and without autism spectrum disorder

The relationship between subjective difficulty in interoceptive processing and accuracy of heartbeat perception in autistic individuals

Most autistic people experience difficulties in sensory processing, including interoceptive processing. For example, they often report subjective difficulties in the interoceptive processing of interoceptive input, such as difficulty in interpreting bodily signals, including hunger, thirst, and fatigue. However, whether these subjective interoceptive difficulties are from underlying problems in interoceptive accuracy remains unclear. This study investigated the relationship between subjective interoceptive difficulty and behavioral interoceptive accuracy in autistic adults and a control group. Subjective interoceptive accuracy was measured using an interoceptive sensitivity questionnaire, and behavioral interoceptive accuracy was measured using a heartbeat counting task. The results showed no significant relationship between subjective interoceptive difficulty and behavioral interoceptive accuracy in the autistic or control groups. This suggests that subjective interoceptive difficulty and behavioral interoceptive accuracy reflect different aspects of interoceptive processing. One possible interpretation is that autistic adults can identify individual local sensory inputs, such as heartbeats, however, they have difficulty integrating multiple inputs and recognizing internal body states such as hunger and fatigue.

Prefrontal Functional Connectivities in Autism Spectrum Disorders: A Connectopathic Disorder Affecting Movement, Interoception, and Cognition

The prefrontal cortex is included in a neuronal system that includes the basal ganglia, the thalamus, and the cerebellum. Most of the higher and more complex motor, cognitive, and emotional behavioral functions are thought to be found primarily in the frontal lobes. Insufficient connectivity between the medial prefrontal cortex (mPFC) and other regions of the brain that are distant from each other involved in top-down information processing rely on the global integration of data from multiple input sources and enhance low level perception processes (bottom-up information processing). The reduced deactivation in mPFC and in the rest of the Default Network during global task processing is consistent with the integrative modulatory role served by the mPFC. We stress the importance of understanding the degree to which sensory and movement anomalies in individuals with autism spectrum disorder (ASD) can contribute to social impairment. Further investigation on the neurobiological basis of sensory symptoms and its relationship to other clinical features found in ASD is required Treatment perhaps should not be first behaviorally based but rather based on facilitating sensory motor development.

Emotional Dysfunction and Interoceptive Challenges in Adults with Autism Spectrum Disorders

People with autism spectrum disorder (ASD) frequently show impaired sensory processing in different senses, including the interoceptive system. Recent findings suggest that interoception is a fundamental component of emotional experience and that impaired interoception is associated with alexithymia. This study aims to explore the association and interrelation between interoceptive confusion, alexithymia, and the capacity for emotional regulation among a sample of 33 adults with ASD compared to a control group of 35 adults with neurotypical development and its mutual impact. The participants answered a series of questionnaires addressing these three variables. The results showed (1) significant differences between the groups in all dimensions, with dysfunctional emotional regulation, impaired interoception, and alexithymia in the ASD group, (2) significant correlations between interoceptive confusion, emotional clarity, and alexithymia in the ASD group but only positive correlations between interoceptive confusion and alexithymia in the CG, and (3) that emotional clarity, alexithymia, and autism explain 61% of the variance in interoceptive confusion. These results are in line with previous studies and suggest that training interoceptive ability may enhance emotional clarity and reduce alexithymia among those diagnosed with ASD, with significant implications in the planning of treatment.

Relationships between alexithymia, interoception, and emotional empathy in autism spectrum disorder

LAY ABSTRACT

Empathy, the ability to understand and share the emotions of others, is a necessary skill for social functioning and can be categorized into cognitive and emotional empathy. There is evidence to suggest that individuals with autism spectrum disorder have difficulties with cognitive empathy, the ability to imagine how another person is thinking or feeling. However, it is unclear if individuals with autism spectrum disorder struggle with emotional empathy, the ability to share and feel emotions others are experiencing. Self-report and interview data were collected to explore the relationships between interoception (individuals' self-reported awareness of sensation from their body such as thirst, heartbeat, etc.), alexithymia (an individual's ability to describe and distinguish between their own emotions), and emotional empathy in 35 youth with autism spectrum disorder and 40 typically developing youth. Greater personal distress to others' emotions and greater difficulty describing and recognizing self-emotions were associated with reporting fewer physical sensations in the body when experiencing emotion in the autism spectrum disorder group. The results of this study suggest that while autism spectrum disorder youth with concomitant alexithymia may experience emotional empathy differently, it should not be characterized as an absence of a capacity for emotional empathy.

Prevalence of autistic traits in functional neurological disorder and relationship to alexithymia and psychiatric comorbidity

INTRODUCTION

In a cohort of adults with Functional Neurological Disorder (FND), we aim to: METHODS: 91 patients participating in a FND 5-week outpatient program completed baseline self-report questionnaires for total phobia, somatic symptom severity, attention deficit hyperactivity disorder (ADHD) and dyslexia. Patients were grouped by Autism Spectrum Quotient (AQ-10) score of <6 or ≥ 6 and compared for significant differences in tested variables. This analysis was repeated with patients grouped by alexithymia status. Simple effects were tested using pairwise comparisons. Multistep regression models tested direct relationships between autistic traits and psychiatric comorbidity scores, and mediation by alexithymia.

RESULTS

36 patients (40%) were AQ-10 positive (scoring ≥6 on AQ-10). A further 36 patients (across AQ-10 positive and AQ-10 negative groups) (40%) screened positive for alexithymia. AQ-10 positive patients scored significantly higher for alexithymia, depression, generalised anxiety, social phobia, ADHD, and dyslexia. Alexithymia positive patients scored significantly higher for generalised anxiety, depression, somatic symptoms severity, social phobia, and dyslexia. Alexithymia score was found to mediate the relationship between autistic trait and depression scores.

CONCLUSION

We demonstrate a high proportion of autistic and alexithymic traits, in adults with FND. A higher prevalence of autistic traits may highlight a need for specialised communication approaches in FND management. Mechanistic conclusions are limited. Future research could explore links with interoceptive data.

Characterizing Interoceptive Differences in Autism: A Systematic Review and Meta-analysis of Case-control Studies

Interoception, the body's perception of its own internal states, is thought to be altered in autism, though results of empirical studies have been inconsistent. The current study systematically reviewed and meta-analyzed the extant literature comparing interoceptive outcomes between autistic (AUT) and neurotypical (NT) individuals, determining which domains of interoception demonstrate robust between-group differences. A three-level Bayesian meta-analysis compared heartbeat counting performance, heartbeat discrimination performance, heartbeat counting confidence ratings, and self-reported interoceptive attention between AUT and NT groups (15 studies; n_AUT = 467, n_NT = 478). Autistic participants showed significantly reduced heartbeat counting performance [g = - 0.333, CrI_95% (- 0.535, - 0.138)] and higher confidence in their heartbeat counting abilities [g = 0.430, CrI_95% (0.123, 0.750)], but groups were equivalent on other meta-analyzed outcomes. Implications for future interoception research in autism are discussed.

Emotional regulation deficits in autism spectrum disorder: The role of alexithymia and interoception

The aim of this study was to analyze emotional regulation, alexithymia and interoception in a group of people diagnosed with ASD (n = 27), a normative population with a technical academic training (n = 30), and another group with a humanities/health training (n = 20). Results showed significantly higher scores in alexithymia and emotional regulation problems, and lower scores in interoception in the ASD group. Also, alexithymia was found to correlate with emotional regulation, which was found to be significant in all three groups. In addition, interoception correlated negatively with alexithymia in the ASD group. Finally, the scores of the group with the technical training were closer to those of the ASD group compared to the humanities/health group.

Validation of the Japanese version of the Interoception Sensory Questionnaire for individuals with autism spectrum disorder

The Interoception Sensory Questionnaire (ISQ) is a self-report instrument used to assess the characteristics of interoceptive processing in individuals with autism spectrum disorder (ASD). Previous studies have shown that scores of the ISQ are more appropriate than other subjective measures for evaluating difficulties in interoceptive processing in individuals with ASD. Yet, no prior research has demonstrated the validation of the ISQ in Japanese samples. This study attempted to validate the Japanese version of the ISQ (ISQ-J) by examining its psychometric properties. We confirmed the score distribution, internal consistency, and factor structure in Japanese samples. We also examined the relationships with other interoceptive questionnaires. In addition, we compared the scores of the ISQ-J between adolescents and adults with ASD participants and control participants. Results of confirmatory factor analyses showed that the reliability of the ISQ-J in adults with ASD reached an acceptable level of a one-factor structure with excellent internal consistency (α = 0.963). The result of the ISQ-J showed a significant positive correlation with the measure of awareness of interoceptive sensitivity for localized bodily states; on the other hand, a significant negative correlation was found with those integrated bodily states. In addition, the ISQ-J scores were significantly higher in the ASD group than in the control group. The current findings depend on self-report data (including a diagnosis of ASD) to measure validity constructs. Additionally, since the ISQ-J was surveyed in adults with ASD, it is unclear whether similar the results would be obtained if the ISQ-J were conducted with children. These results indicate the validity and reliability of the ISQ-J and provide a tool for assessing confusion of interoceptive information in Japanese adults with ASD.

The associations between autistic traits and disordered eating/drive for muscularity are independent of anxiety and depression in females but not males

Previous research has shown a positive correlation between autistic traits and eating disorder symptoms, and this relationship appears to be independent of co-occurring mental health status. The current study followed a pre-registered analysis plan with the aim to investigate a previously unconsidered factor in the relationship between autistic traits and disorders of eating and body image: the drive for muscularity. Participants (N = 1068) completed the Autism Spectrum Quotient (AQ), Hospital Anxiety and Depression Scale (HADS), Eating Attitudes Test-26 (EAT-26) and Drive for Muscularity Scale (DMS). Positive correlations between AQ and EAT-26 and AQ and DMS were observed. In females, AQ remained significantly correlated with EAT-26 and DMS when controlling for co-occurring anxiety and depression symptoms, but this was not the case in males. These findings demonstrate the moderating role of sex, and the need to consider autistic traits in individuals diagnosed with, or at a heightened risk for, disorders of eating and body image.

A capabilities approach to understanding and supporting autistic adulthood

There is little comprehensive research into autistic adulthood, and even less into the services and supports that are most likely to foster flourishing adult autistic lives. This limited research is partly because autism is largely conceived as a condition of childhood, but this focus of research has also resulted from the orthodox scientific approach to autism, which conceptualizes autistic experience almost entirely as a series of biologically derived functional deficits. Approaching autism in this way severely limits what is known about this neurodevelopmental difference, how research is conducted and the services and supports available. In this Review, we adopt an alternative research strategy: we apply Martha Nussbaum’s capabilities approach, which focuses on ten core elements of a thriving human life, to research on autistic adulthood. In doing so, we identify areas where autistic adults thrive and where they often struggle, and highlight issues to which researchers, clinicians and policymakers should respond. The resulting picture is far more complex than conventional accounts of autism imply. It also reveals the importance of engaging autistic adults directly in the research process to make progress towards genuinely knowing autism and supporting flourishing autistic lives.

The focus on functional deficits in conventional autism research constrains understanding of autistic lives. In this Review, Pellicano et al. appraise research on autistic adulthood through a capabilities lens to identify areas where autistic adults thrive, and where more research and services are needed to enhance their quality of life.

Alexithymia and intolerance of uncertainty predict somatic symptoms in autistic and non-autistic adults

LAY ABSTRACT

Autistic people have more physical health problems than non-autistic people. We were interested in whether autistic people experience more discomfort in their bodies than non-autistic people and whether certain psychological traits contribute to that. A survey was completed online by older adolescents and adults, 51 of whom were autistic, 32 of whom thought they might be autistic but were not diagnosed and 119 who were not autistic. They completed measures of somatic symptoms (daily experience of pain, discomfort, dizziness), alexithymia (difficulty identifying and expressing feelings), interoception (how much people are aware of their bodies) and intolerance of uncertainty (how people handle doubt or uncertainty), and reported any physical or mental health conditions. We found that the autistic participants had more physical and mental health conditions than the non-autistic participants, but even when we took account of this, they experienced higher levels of somatic symptoms. We looked at which psychological factors influenced levels of somatic symptoms across the whole sample, and found that alexithymia, intolerance of uncertainty, having physical health problems, being female and the number of mental health conditions predicted somatic symptoms, while interoception and autism diagnosis did not. The findings suggest that people may be more likely to experience physical discomfort if they are female, and have difficulty identifying and expressing feeling and difficulty tolerating doubt. As these psychological factors are more prominent in autism, we think this is important for physical and mental health providers to know about, so that these psychological factors can be considered when assessing and treating autistic people.

Understanding Challenging Behaviors in Autism Spectrum Disorder: A Multi-Component, Interdisciplinary Model

A multi-component, interdisciplinary model is described which explains the presence of, and in other cases the lack of, many challenging behaviors associated with autism spectrum disorder (ASD). More specifically, the model expands the operant behavioral conditioning paradigm by taking into account medical comorbidities and interoceptive processing.

Relationships between autistic traits, taste preference, taste perception, and eating behaviour

Individuals with autism spectrum disorder exhibit atypical taste perception and eating behaviours. However, little is known about the effect of autistic traits on eating behaviours in the general population. This study explored the relationships between autistic traits, taste preferences, taste perceptions, and eating behaviours among Japanese population using an online questionnaire survey. The results showed significant effect of autistic traits on eating behaviours, that people with higher autistic traits tended to have higher selective eating behaviours, such as increased sensitivity to food texture and mixed flavours. Moreover, selective eating behaviours were correlated with the preference for sour taste and aftertaste sensitivity. Those results suggest that eating behaviours can be influenced by the relationship between autistic traits, taste perceptions, and taste preferences. We discuss these results in the context of previous findings, and future investigations into the possibility of solving selective eating problems in individuals with autism.

Autistic traits were significantly correlated with eating behaviours.

People with higher autistic traits tended to have higher selective eating behaviours, such as increased sensitivity to food texture and mixed flavours.

People who like sour tastes tended to have less selective eating behaviours.

People who are sensitive to aftertaste perception tended to have greater selective eating behaviours.

Autistic traits, taste perceptions, and taste preferences play a role in the development of a number of selective eating behaviours.

Emoji Identification and Emoji Effects on Sentence Emotionality in ASD-Diagnosed Adults and Neurotypical Controls

We investigated ASD-diagnosed adults' and neurotypical (NT) controls' processing of emoji and emoji influence on the emotionality of otherwise-neutral sentences. Study 1 participants categorised emoji representing the six basic emotions using a fixed-set of emotional adjectives. Results showed that ASD-diagnosed participants' classifications of fearful, sad, and surprised emoji were more diverse and less 'typical' than NT controls' responses. Study 2 participants read emotionally-neutral sentences; half paired with sentence-final happy emoji, half with sad emoji. Participants rated sentence + emoji stimuli for emotional valence. ASD-diagnosed and NT participants rated sentences + happy emoji as equally-positive, however, ASD-diagnosed participants rated sentences + sad emoji as more-negative than NT participants. We must acknowledge differential perceptions and effects of emoji, and emoji-text inter-relationships, when working with neurodiverse stakeholders.

The role of interoception in the overlap between eating disorders and autism: Methodological considerations

Significant comorbidity has been demonstrated between feeding and eating disorders and autism. Atypical interoception (perception of bodily signals) may, at least in part, be responsible for this association, as it has been implicated in the aetiology of both conditions. However, significant methodological limitations are impeding progress in this area. This paper provides a brief overview of how interoception has been linked to autism and feeding and eating disorders in both adolescent and adult populations before identifying several issues with current measures of interoception. We suggest that methodological issues may be contributing to the inconsistency in the empirical literature, and provide suggestions for future research.

Atypical interoception is linked to both feeding and eating disorders, and autism and may contribute to the comorbidity between the two.

Existing measures of interoception across cardiac, gastric and respiratory domains are severely limited.

Novel and better‐validated measures of interoception will allow us to better understand the clinical potential of interoceptive training.

Gastrointestinal concerns in children with autism spectrum disorder: A qualitative study of family experiences

LAY ABSTRACT

Gastrointestinal problems are common in the autism spectrum disorder community and may affect both the person with autism spectrum disorder and their families. However, little research is available on the experiences of families who have a child with both autism spectrum disorder and gastrointestinal symptoms. We held one-on-one interviews with 12 parents of children who had both autism spectrum disorder and gastrointestinal symptoms. We analyzed the raw text responses from these interviews and identified four main themes. First, parents shared that their children had trouble verbally communicating when they were experiencing gastrointestinal symptoms (Theme 1). This led parents to use bodily signs, such as changes in the stool, and non-verbal behaviors, such as irritability, to recognize when their child was having gastrointestinal symptoms. Next, gastrointestinal issues affected both the child's well-being and their ability to attend class and extracurricular or social activities (Theme 2). The gastrointestinal issues also affected the family's routines, overall well-being, and their ability to go out and do activities together as a family (Theme 3). Finally, parents often had challenges receiving accessible and quality healthcare for their child's gastrointestinal problems (Theme 4). Together, these findings highlight the enormous burden that gastrointestinal symptoms have on the wellness of children with autism spectrum disorder and their families.

What Is Social about Autism? The Role of Allostasis-Driven Learning

Scientific research on neuro-cognitive mechanisms of autism often focuses on circuits that support social functioning. However, autism is a heterogeneous developmental variation in multiple domains, including social communication, but also language, cognition, and sensory-motor control. This suggests that the underlying mechanisms of autism share a domain-general foundation that impacts all of these processes. In this Perspective Review, we propose that autism is not a social deficit that results from an atypical "social brain". Instead, typical social development relies on learning. In social animals, infants depend on their caregivers for survival, which makes social information vitally salient. The infant must learn to socially interact in order to survive and develop, and the most prominent learning in early life is crafted by social interactions. Therefore, the most prominent outcome of a learning variation is atypical social development. To support the hypothesis that autism results from a variation in learning, we first review evidence from neuroscience and developmental science, demonstrating that typical social development depends on two domain-general processes that determine learning: (a) motivation, guided by allostatic regulation of the internal milieu; and (b) multi-modal associations, determined by the statistical regularities of the external milieu. These two processes are basic ingredients of typical development because they determine allostasis-driven learning of the social environment. We then review evidence showing that allostasis and learning are affected among individuals with autism, both neurally and behaviorally. We conclude by proposing a novel domain-general framework that emphasizes allostasis-driven learning as a key process underlying autism. Guided by allostasis, humans learn to become social, therefore, the atypical social profile seen in autism can reflect a domain-general variation in allostasis-driven learning. This domain-general view raises novel research questions in both basic and clinical research and points to targets for clinical intervention that can lower the age of diagnosis and improve the well-being of individuals with autism.

Interoceptive training to target anxiety in autistic adults (ADIE): A single-center, superiority randomized controlled trial

BACKGROUND

This trial tested if a novel therapy, Aligning Dimensions of Interoceptive Experience (ADIE), reduces anxiety in autistic adults. ADIE targets the association of anxiety with mismatch between subjective and behavioral measures of an individual's interoceptive sensitivity to bodily signals, including heartbeats.

METHODS

In this superiority randomized controlled trial, autistic adults (18-65 years) from clinical and community settings in Southern England were randomly assigned (1:1) to receive six sessions of ADIE or an active 'exteroceptive' control therapy (emotional prosody identification). Researchers conducting outcome assessments were blind to allocation. ADIE combines two modified heartbeat detection tasks with performance feedback and physical activity manipulation that transiently increases cardiac arousal. Participants were followed-up one-week (T1) and 3-months post-intervention (T2). The primary outcome was Spielberger Trait Anxiety Score (STAI-T) at T2. Outcomes were assessed on an intention-to-treat basis using multiple imputation for dealing with missing values. This trial was registered at International Standard Randomized Controlled Trial Registry, ISRCTN14848787.

FINDINGS

Between July 01, 2017, and December 31, 2019, 121 participants were randomly allocated to ADIE (n = 61) or prosody (n = 60) intervention groups. Data at T1 was provided by 85 (70%) participants (46 [75%] ADIE; 39 [65%] prosody). Data at T2 was provided by 61 (50%) participants (36 [59%] ADIE; 25 [42%] prosody). One adverse event (cardiac anxiety following ADIE) was recorded. A statistically significant group effect of ADIE on trait anxiety continued at T2 (estimated mean difference 3•23 [95% CI 1•13 to 5•29]; d = 0•30 [95% CI 0•09 to 0•51]; p = 0•005) with 31% of ADIE group participants meeting trial criteria for recovery (compared to 16% in the control group).

INTERPRETATION

ADIE can reduce anxiety in autistic adults, putatively improving regulatory control over internal stimuli. With little reliance on language and emotional insight, ADIE may constitute an inclusive intervention.

FUNDING MQ

Transforming Mental Health PsyImpact Grant.

Psychometric validation and refinement of the Interoception Sensory Questionnaire (ISQ) in adolescents and adults on the autism spectrum

BACKGROUND

Individuals on the autism spectrum are reported to display alterations in interoception, the sense of the internal state of the body. The Interoception Sensory Questionnaire (ISQ) is a 20-item self-report measure of interoception specifically intended to measure this construct in autistic people. The psychometrics of the ISQ, however, have not previously been evaluated in a large sample of autistic individuals.

METHODS

Using confirmatory factor analysis, we evaluated the latent structure of the ISQ in a large online sample of adults on the autism spectrum and found that the unidimensional model fit the data poorly. Using misspecification analysis to identify areas of local misfit and item response theory to investigate the appropriateness of the seven-point response scale, we removed redundant items and collapsed the response options to put forth a novel eight-item, five-response choice ISQ.

RESULTS

The revised, five-response choice ISQ (ISQ-8) showed much improved fit while maintaining high internal reliability. Differential item functioning (DIF) analyses indicated that the items of the ISQ-8 were answered in comparable ways by autistic adolescents and adults and across multiple other sociodemographic groups.

LIMITATIONS

Our results were limited by the fact that we did not collect data for typically developing controls, preventing the analysis of DIF by diagnostic status. Additionally, while this study proposes a new 5-response scale for the ISQ-8, our data were not collected using this method; thus, the psychometric properties for the revised version of this instrument require further investigation.

CONCLUSION

The ISQ-8 shows promise as a reliable and valid measure of interoception in adolescents and adults on the autism spectrum, but additional work is needed to examine its psychometrics in this population. A free online score calculator has been created to facilitate the use of ISQ-8 latent trait scores for further studies of autistic adolescents and adults (available at https://asdmeasures.shinyapps.io/ISQ_score/ ).

Exploring Social Biomarkers in High-Functioning Adults with Autism and Asperger's Versus Healthy Controls: A Cross-Sectional Analysis

Biomarkers for autism spectrum disorder (ASD) are lacking but would facilitate drug development for the core deficits of the disorder. We evaluated markers proposed for characterization of differences in social communication and interaction in adults with ASD versus healthy controls (HC) for utility as biomarkers. Data pooled from an observational study and baseline data from a placebo-controlled study were analyzed. Between-group differences were observed in eye-tracking tasks for activity monitoring, biomotion, human activity preference, composite score (p = 0.0001-0.037) and pupillometry (various tasks, p = 0.017-0.05). Impaired olfaction was more common in the ASD sample versus HC (p = 0.018). Our preliminary results suggest the potential use for stratification and response sub-analyses outcome-prediction of specific eye-tracking tasks, pupillometry and olfaction tests in ASD trials.

A Contemplative Biofeedback Intervention for Adults with Autism Spectrum Disorder: Feasibility of a Community-Based Treatment

As the number of diagnosed adults living with autism spectrum disorder (ASD) continues to grow, a lack of resources and lack of available interventions exacerbate their low quality of life, including low levels of education and employment, and high levels of co-morbid anxiety and depression. Here we build upon existing research showing the effectiveness of contemplative interventions on individuals with ASD, to provide a low-cost biofeedback-enhanced training which can be implemented by non-professional staff, and may help autistic individuals grasp abstract contemplative techniques. We hypothesize that the intervention will decrease participants' anxiety and autism symptoms, and increase their self-awareness, self-determination, and empathy. Fourteen adults with ASD, residing in assisted living, were provided with 16 weekly half-hour contemplative-biofeedback sessions with non-professional trainers, in which they learned to reduce their arousal levels through combined biofeedback and contemplative techniques, and apply those to everyday life. Quantitative and qualitative data was collected pre- and post-intervention, to determine changes in participants' self-awareness, self-determination, anxiety, autism symptoms, and empathy. Participants were capable of successfully improving their physiological arousal levels on the biofeedback setup, indicating feasibility of the technique. Further, we found initial indications for reduction in autism symptoms and increased self-determination. Qualitative reports by participants and counselors revealed that participants applied the techniques in many real-life situations, and these had far-ranging effects on their emotional regulation, work and social motivation, and self-determination. The study provides proof-of-concept for a low-cost, community-based intervention which can ameliorate the lives of adults with ASD.

First-Hand Accounts of Interoceptive Difficulties in Autistic Adults

Interoceptive awareness refers to one's ability to detect, discriminate, and regulate internal bodily and mental processes. Interoceptive challenges in ASD remain under researched and poorly understood. In this study, we analyzed texts of adults who self-identify as autistic describing their interoceptive challenges. Many individuals described limited awareness of hunger, satiation, or thirst, which contributed to eating disordered behavior in some instances. Others described limited awareness or difficulty understanding affective arousal, pain or illness, and difficulty differentiating benign body signals from signals that represent medical concerns. Findings from this study call for increased research attention on this topic, and a need for valid and objective measures for assessing interoception in ASD.

Neural Correlates of Cardiac Interoceptive Focus Across Development: Implications for Social Symptoms in Autism Spectrum Disorder

Interoception involves the processing of sensory information relevant to physiological functioning and is integral to building self-awareness, emotional states, and modulating social behaviors. With the role of interoception in emotional processing and social functioning, there is growing interest in characterizing interoception in autism spectrum disorder (ASD), yet, there are mixed results regarding cardiac interoceptive accuracy in ASD. In this study, we explored the neural basis of cardiac interoception using an fMRI heartbeat-counting task in order to assess neural correlates of primary interoception. We predicted that interoceptive-specific response in the insula, a "hub" for interoception, would be related to ASD symptomatology. We investigated the relationship of insula responses during cardiac interoceptive focus and a self/caregiver-reported autism-related symptom scale (Social Responsiveness Scale-2 (SRS)). Participants included 46 individuals with autism spectrum disorder (ASD) (age 8-54, mean = 19.43 ± 10.68 years) and 54 individuals with typical development for comparison (TC, age 8-53, mean = 21.43 ± 10.41 years). We found no significant difference in cardiac interoceptive accuracy or neural response to cardiac interoception focus in ASD. Several insula subdivisions had a curvilinear relationship to age, peaking in early adulthood. Interoceptive-specific insula response was associated with adult self-report SRS scores; this association differed by diagnostic group and was not present for caregiver-reported scores. This work suggests that (a) there is no global deficit in cardiac interoception in ASD, but integrating interoceptive cues with social information may distinguish individuals with ASD, and (b) there is a developmental trajectory for interoceptive processing in the insula that may be relevant for socio-emotional health. Autism Res 2020, 13: 908-920. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We use internal sensory information from the body, such as signals from the heart, to understand our emotional response to the external world. We measured how accurately people with autism feel their heartbeat and how the brain responds to this type of information. We found no differences between the autism and comparison groups in how the brain senses heartbeats, or in how accurately people feel their heartbeats. However, for people with autism, brain responses while sensing heartbeats were related to social difficulties. This work suggests people with autism may use internal and external information in a different way.

Complementary and Alternative Treatments for Autism Spectrum Disorders: A Review for Parents and Clinicians

Complementary and alternative therapy (CAT) methods for children with autism spectrum disorders (ASD) are widespread in European countries and the Russian Federation; however, their efficacy and safety is not routinely considered by parents and clinicians when recommended or used. The current narrative review presents the most widely known CAT interventions for children with ASD synthesizing data from meta-analyses, systematic reviews, and randomized controlled trials obtained from the PubMed database based on the safety-efficacy model. We have found that, of the reviewed CATs, only the melatonin intervention can be considered safe and effective for children with ASD with comorbid sleep problems. The methods that were classified as safe but had inconclusive efficacy are recommended to be implemented only when they do not interfere with front line treatment for ASD, Applied Behavior Analysis (ABA). Methods with the lack of current evidence for the efficacy such as auditory integration therapies, bioacoustic correction, sensory integration therapy, micropolarization, animal assisted therapy, and dietary interventions should not be recommended as alternative treatments and can only be used as complimentary to ABA-based interventions. We advise against the use of chelation, hyperbaric oxygen therapy, and holding therapy due their documented harmful psychological and physical effects. When considering CAT for ASD we recommend parents and clinicians use the criteria suggested by Lofthouse and colleagues [59]: only the therapies that are safe, easy, cheap, and sensible can be recommended and used, as opposed to therapies that are risky, unrealistic, difficult, or expensive that should not be recommended or utilized.

Guided self-help for depression in autistic adults: the ADEPT feasibility RCT

BACKGROUND

Co-occurring depression frequently occurs in autism. Evidence-based psychological interventions have been successfully adapted to treat co-occurring anxiety, but there is little evidence about the usefulness of adapted cognitive-behavioural therapy for depression. To the authors' knowledge, to date there have been no randomised trials investigating the usefulness of low-intensity cognitive-behavioural therapy for depression in autism.

OBJECTIVES

The objectives of the study were to (1) develop a low-intensity psychological intervention for depression adapted for autism, (2) assess the feasibility and patient and therapist acceptability of the intervention, (3) estimate the rates of recruitment and retention for a full-scale randomised controlled trial and (4) identify an appropriate measure of depression to be used in a full-scale randomised controlled trial.

DESIGN

The study comprised a randomised controlled trial (n = 70) with a nested qualitative evaluation (n = 21). Seventy eligible and consenting participants were randomly allocated to guided self-help or to treatment as usual.

SETTING

Adult autism services in two NHS regions.

PARTICIPANTS

Adults with a diagnosis of autism spectrum disorder with depression, that is, a Patient Health Questionnaire-9 items score of ≥ 10. People who had attended more than six sessions of cognitive-behavioural therapy in the previous 6 months were excluded.

INTERVENTIONS

The low-intensity intervention (guided self-help) comprised materials for nine individual sessions, based on behavioural activation adapted for autism, facilitated by therapist guides (coaches) who were graduate-level psychologists who attended training and regular supervision. Treatment as usual was standard NHS care for depression.

MAIN OUTCOME MEASURES

Outcomes were measured 10, 16 and 24 weeks post randomisation using self-report and interview measures of depression, anxiety, obsessive-compulsive symptoms, social function and quality of life, and a health-care and service use questionnaire. As this was a feasibility study also designed to identify the most appropriate measure of depression, it was not possible to specify the primary outcome measure or outcome point a priori.

RESULTS

The aims of the study were met in full. The guided self-help intervention was feasible and well received by participants and coaches. The majority of allocated participants attended the intervention in full. The most practical outcome point was determined to be 16 weeks. There were differential rates of attrition across the treatment groups: 86% of the guided self-help group remained in the study at 24 weeks, compared with 54% of treatment as usual group. The qualitative study suggested that guided self-help had enhanced credibility with participants at the point of randomisation. Inter-rater reliability of the interview measure of depression was less than adequate, limiting the conclusions that can be drawn from the prespecified sensitivity to change analyses.

CONCLUSIONS

The intervention was feasible and well received. Although this feasibility study was not a fully powered trial, it provided some evidence that the guided self-help intervention was effective in reducing depressive symptoms. A full-scale clinical effectiveness and cost-effectiveness trial of the intervention is warranted.

FUTURE WORK

Improvements to the intervention materials as a result of qualitative interviews. Stakeholder consultation to consider future trial design, consider strategies to improve retention in a treatment as usual arm and select a self-report measure of depression to serve as the primary outcome measure.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN54650760.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 68. See the NIHR Journals Library website for further project information. This study was also supported by the NIHR Biomedical Research Centre at the University Hospitals Bristol NHS Foundation Trust and the University of Bristol.

The Feeling of Me Feeling for You: Interoception, Alexithymia and Empathy in Autism

Following recent evidence for a link between interoception, emotion and empathy, we investigated relationships between these factors in autism spectrum disorder (ASD). 26 adults with ASD and 26 healthy participants completed tasks measuring interoception, alexithymia and empathy. ASD participants with alexithymia demonstrated lower cognitive and affective empathy than ASD participants without alexithymia. ASD participants showed reduced interoceptive sensitivity (IS), and also reduced interoceptive awareness (IA). IA was correlated with empathy and alexithymia, but IS was related to neither. Alexithymia fulfilled a mediating role between IA and empathy. Our findings are suggestive of an alexithymic subgroup in ASD, with distinct interoceptive processing abilities, and have implications for diagnosis and interventions.

Four Social Brain Regions, Their Dysfunctions, and Sequelae, Extensively Explain Autism Spectrum Disorder Symptomatology

Autism spectrum disorder (ASD) is a challenging neurodevelopmental disorder with symptoms in social, language, sensory, motor, cognitive, emotional, repetitive behavior, and self-sufficient living domains. The important research question examined is the elucidation of the pathogenic neurocircuitry that underlies ASD symptomatology in all its richness and heterogeneity. The presented model builds on earlier social brain research, and hypothesizes that four social brain regions largely drive ASD symptomatology: amygdala, orbitofrontal cortex (OFC), temporoparietal cortex (TPC), and insula. The amygdala's contributions to ASD largely derive from its major involvement in fine-grained intangible knowledge representations and high-level guidance of gaze. In addition, disrupted brain regions can drive disturbance of strongly interconnected brain regions to produce further symptoms. These and related effects are proposed to underlie abnormalities of the visual cortex, inferior frontal gyrus (IFG), caudate nucleus, and hippocampus as well as associated symptoms. The model is supported by neuroimaging, neuropsychological, neuroanatomical, cellular, physiological, and behavioral evidence. Collectively, the model proposes a novel, parsimonious, and empirically testable account of the pathogenic neurocircuitry of ASD, an extensive account of its symptomatology, a novel physiological biomarker with potential for earlier diagnosis, and novel experiments to further elucidate the mechanisms of brain abnormalities and symptomatology in ASD.

Oxytocin and Prader-Willi Syndrome

In the chapter, we explore the relationship between the peptide hormone, oxytocin (OT), and behavioral and metabolic disturbances observed in the genetic disorder Prader-Willi Syndrome (PWS). Phenotypic and genotypic characteristics of PWS are described, as are the potential implications of an abnormal OT system with respect to neural development including the possible effects of OT dysfunction on interactions with other regulatory mediators, including neurotransmitters, neuromodulators, and hormones. The major behavioral characteristics are explored in the context of OT dysfunction, including hyperphagia, impulsivity, anxiety and emotion dysregulation, sensory processing and interoception, repetitive and restrictive behaviors, and dysfunctional social cognition. Behavioral overlaps with autistic spectrum disorders are discussed. The implications of OT dysfunction on the mechanisms of reward and satiety and their possible role in informing behavioral characteristics are also discussed. Treatment implications and future directions for investigation are considered.

Balance Performance in Autism: A Brief Overview

Children with autism not only have limited social and communicative skills but also have motor abnormalities, such as poor timing and coordination of balance. Moreover, impaired gross motor skills hamper participation with peers. Balance control is interesting from a cognitive science perspective, since it involves a complex interplay between information processing, motor planning, and timing and sequencing of muscle movements. In this paper, we discuss the background of motor problems in children with autism, focusing on how posture is informed by sensory information processing. We also discuss the neurobiological basis of balance problems, and how this is related to anxiety in this group. We then discuss possible avenues for treatment of autism spectrum disorder (ASD) symptoms, especially as regards movement-related interventions. Finally, we present a theoretical outlook and discuss whether some of the symptoms in ASD can be understood from an embodied cognition perspective.

Language and alexithymia: Evidence for the role of the inferior frontal gyrus in acquired alexithymia

The clinical relevance of alexithymia, a condition associated with difficulties identifying and describing one's own emotion, is becoming ever more apparent. Increased rates of alexithymia are observed in multiple psychiatric conditions, and also in neurological conditions resulting from both organic and traumatic brain injury. The presence of alexithymia in these conditions predicts poorer regulation of one's emotions, decreased treatment response, and increased burden on carers. While clinically important, the aetiology of alexithymia is still a matter of debate, with several authors arguing for multiple 'routes' to impaired understanding of one's own emotions, which may or may not result in distinct subtypes of alexithymia. While previous studies support the role of impaired interoception (perceiving bodily states) in the development of alexithymia, the current study assessed whether acquired language impairment following traumatic brain injury, and damage to language regions, may also be associated with an increased risk of alexithymia. Within a sample of 129 participants with penetrating brain injury and 33 healthy controls, neuropsychological testing revealed that deficits in a non-emotional language task, object naming, were associated with alexithymia, specifically with difficulty identifying one's own emotions. Both region-of-interest and whole-brain lesion analyses revealed that damage to language regions in the inferior frontal gyrus was associated with the presence of both this language impairment and alexithymia. These results are consistent with a framework for acquired alexithymia that incorporates both interoceptive and language processes, and support the idea that brain injury may result in alexithymia via impairment in any one of a number of more basic processes.

Autism spectrum disorder and interoception: Abnormalities in global integration?

Research over the past three decades has seen a revived interest in the way the human body—and the way in which it is perceived—interacts with aspects of our experience. Consequently, interoception (i.e. the perception of physiological feedback from the body) has recently been shown to be associated with a wide range of cognitive, emotional, and affective functions, making it broadly relevant to the study of autism spectrum disorder. Although limited qualitative accounts and empirical studies suggest that individuals with autism spectrum disorder encounter abnormalities when perceiving and integrating physiological feedback from their bodies, other studies have suggested that people with/without autism spectrum disorder do not differ in interoceptive ability after accounting for alexithymia. In this article, we discuss the newly recognized importance of interoception in autism spectrum disorder with a focus on how deficits in the perception of bodily feedback might relate to the core features and co-occuring psychopathology of autism spectrum disorder. Finally, a new integrated theory is advanced which posits that people with autism spectrum disorder may experience a reduced capacity to integrate interoceptive information that may result in a narrow attentional bodily focus and reduced motivational and behavioral drives.

Brief Report: Body Image in Autism: Evidence from Body Size Estimation

Individuals with autism spectrum disorder (ASD) have difficulties with social interaction and communication. First-hand accounts written by individuals with ASD have shown the existence of other atypical characteristics such as difficulties with body awareness. However, few studies have examined whether such atypicalities are found more generally among individuals with ASD. We examined body image (i.e., self-body awareness) by asking individuals with ASD and typically developing (TD) individuals to estimate their own body size (shoulder width). Results show that TD individuals estimated their shoulder width more accurately than individuals with ASD. This study suggests that individuals with ASD often experience misperceptions in their body size.

Disrupted integration of exteroceptive and interoceptive signaling in autism spectrum disorder

In addition to deficits in social communication, individuals diagnosed with Autism Spectrum Disorder (ASD) frequently exhibit changes in sensory and multisensory function. Recent evidence has focused on changes in audiovisual temporal processing, and has sought to relate these sensory-based changes to weaknesses in social communication. These changes in audiovisual temporal function manifest as differences in the temporal epoch or "window" within which paired auditory and visual stimuli are integrated or bound, with those with ASD exhibiting expanded audiovisual temporal binding windows (TBWs). However, it is unknown whether this impairment is unique to audiovisual pairings, perhaps because of their relevance for speech processing, or whether it generalizes across pairings in different sensory modalities. In addition to the exteroceptive senses, there has been growing interest in ASD research in interoception (e.g., the monitoring of respiration, heartbeat, hunger, etc.), as these internally directed sensory processes appear to be altered as well in autism. In the current study, we sought to examine both exteroception and interoception in individuals with ASD and a group of typically developing (TD) matched controls, with an emphasis on temporal perception of audiovisual (exteroceptive) and cardiovisual (interoceptive to exteroceptive) cues. Results replicate prior findings showing expanded audiovisual TBWs in ASD in comparison to TD. In addition, strikingly, cardiovisual TBWs were fourfold larger in ASD than in TD, suggesting a putative complete lack of cardiovisual temporal acuity in ASD individuals. Results are discussed in light of recent evidence indicating a reduced tendency to rely on sensory priors in ASD. Autism Res 2018, 11: 194-205. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

Studies have shown that individuals with autism have difficulty in separating auditory and visual events in time. People with autism also weight sensory evidence originating from the external world and from their body differently. We measured simultaneity judgments regarding visual and auditory events and between visual and heartbeat events. Results suggest that while individuals with autism show unusual temporal function across the senses in a general manner, this deficit is greater when pairings bridged between the external world and the internal body.

Sensory Clusters of Adults With and Without Autism Spectrum Conditions

We identified clusters of atypical sensory functioning adults with ASC by hierarchical cluster analysis. A new scale for commonly self-reported sensory reactivity was used as a measure. In a low frequency group (n = 37), all subscale scores were relatively low, in particular atypical sensory/motor reactivity. In the intermediate group (n = 17) hyperreactivity, sensory interests and sensory/motor issues were significantly elevated in relation to the first group, but not hyporeactivity. In a high frequency subgroup (n = 17) all subscale scores were significantly elevated and co-occurrence of hyper- and hyporeactivity was evident. In a population sample, a cluster of low scorers (n = 136) and high scorers relative to the other cluster (n = 26) was found. Identification of atypical sensory reactivity is important for targeting support.

Neurodevelopmental Hypothesis about the Etiology of Autism Spectrum Disorders

Previous models or hypotheses of autism spectral disorder (ASD) failed to take into full consideration the chronological and causal developmental trajectory, leading to the emergence of diverse phenotypes through a complex interaction between individual etiologies and environmental factors. Those phenotypes include persistent deficits in social communication and social interaction (criteria A in DSM-5), and restricted, repetitive patterns of behavior, interests, or activities (criteria B in DSM-5). In this article, we proposed a domain-general model that can explain criteria in DSM-5 based on the assumption that the same etiological mechanism would trigger the various phenotypes observed in different individuals with ASD. In the model, we assumed the following joint causes as the etiology of autism: (1) Hypoplasia of the pons in the brainstem, occurring immediately following neural tube closure; and (2) Deficiency in the GABA (γ-aminobutyric acid) developmental switch during the perinatal period. Microstructural abnormalities of the pons directly affect both the structural and functional development of the brain areas strongly connected to it, especially amygdala. The impairment of GABA switch could not only lead to the deterioration of inhibitory processing in the neural network, but could also cause abnormal cytoarchitecture. We introduced a perspective that atypical development in both brain structure and function can give full explanation of diverse phenotypes and pathogenetic mechanism of ASD. Finally, we discussed about neural mechanisms underlying the phenotypic characteristics of ASD that are not described in DSM-5 but should be considered as important foundation: sleep, global precedence, categorical perception, intelligence, interoception and motor control.

Intrainsular connectivity and somatosensory responsiveness in young children with ASD

BACKGROUND

The human somatosensory system comprises dissociable paths for discriminative and affective touch, reflected in separate peripheral afferent populations and distinct cortical targets. Differences in behavioral and neural responses to affective touch may have an important developmental role in early social experiences, which are relevant for autism spectrum disorder (ASD).

METHODS

Using probabilistic tractography, we compared the structural integrity of white matter pathways for discriminative and affective touch in young children with ASD and their typically developing (TD) peers. We examined two tracts: (1) a tract linking the thalamus with the primary somatosensory cortex, which carries discriminative tactile information, and (2) a tract linking the posterior insula-the cortical projection target of unmyelinated tactile afferents mediating affective touch-with the anterior insula, which integrates sensory and visceral inputs to interpret emotional salience of sensory stimuli. We investigated associations between tract integrity and performance on a standardized observational assessment measuring tactile discrimination and affective responses to touch.

RESULTS

Both the thalamocortical and intrainsular tracts showed reduced integrity (higher mean diffusivity) in the ASD group compared to those in the TD group. Consistent with the previous findings, the ASD group exhibited impaired tactile discriminative ability, more tactile defensiveness, and more sensory seeking (e.g., enthusiastic play or repetitive engagement with a specific tactile stimulus). There was a significant relation between intrainsular tract integrity and tactile seeking. The direction of this relation differed between groups: higher intrainsular mean diffusivity (MD) (reflecting decreased tract integrity) was associated with increased tactile seeking in the TD group but with decreased tactile seeking in the ASD group. In the TD group, decreased tactile defensiveness was also associated with higher intrainsular MD, but there was no relation in the ASD group. Discriminative touch was not significantly associated with integrity of either tract in either group.

CONCLUSIONS

These results support previous findings suggesting a central role for the insula in affective response to touch. While both discriminative and affective touch and both somatosensory tracts are affected in ASD, the restriction of brain-behavior associations to the intrainsular tract and tactile seeking suggests more complex and perhaps higher-order influence on differences in tactile defensiveness and discrimination.

Associations Between Interoceptive Cognition and Age in Autism Spectrum Disorder and Typical Development

Interoceptive awareness is linked to emotional and social cognition, which are impaired in individuals with autism spectrum disorder (ASD). It is unknown how this ability is associated with age in either typical or atypical development. We used a standard test of interoceptive accuracy (IA) to investigate these questions in children and adults with and without ASD. Perceived number of heartbeats over 4 time intervals was compared with actual heart rate to determine IA. Effects of group, age, IQ, heart rate, and mental counting ability on accuracy were assessed using multiple regression. Post hoc correlations were performed to clarify significant interactions. Age was unrelated to IA in both groups when IQ ≥115. When IQ <115, this relationship was positive in typical development and negative in ASD. These results suggest that cognitive ability moderates the effect of age on IA differently in autism and typical development.

Emotional decision-making in autism spectrum disorder: the roles of interoception and alexithymia

The way choices are framed influences decision-making. These “framing effects” emerge through the integration of emotional responses into decision-making under uncertainty. It was previously reported that susceptibility to the framing effect was reduced in individuals with autism spectrum disorder (ASD) due to a reduced tendency to incorporate emotional information into the decision-making process. However, recent research indicates that, where observed, emotional processing impairments in ASD may be due to co-occurring alexithymia. Alexithymia is thought to arise due to impaired interoception (the ability to perceive the internal state of one’s body), raising the possibility that emotional signals are not perceived and thus not integrated into decision-making in those with alexithymia and that therefore reduced framing effects in ASD are a product of co-occurring alexithymia rather than ASD per se. Accordingly, the present study compared framing effects in autistic individuals with neurotypical controls matched for alexithymia. Results showed a marked deviation between groups. The framing effect was, in line with previous data, significantly smaller in autistic individuals, and there was no relationship between alexithymia or interoception and decision-making in the ASD group. In the neurotypical group, however, the size of the framing effect was associated with alexithymia and interoception, even after controlling for autistic traits. These results demonstrate that although framing effects are associated with interoception and alexithymia in the neurotypical population, emotional and interoceptive signals have less impact upon the decision-making process in ASD.

Active interoceptive inference and the emotional brain

We review a recent shift in conceptions of interoception and its relationship to hierarchical inference in the brain. The notion of interoceptive inference means that bodily states are regulated by autonomic reflexes that are enslaved by descending predictions from deep generative models of our internal and external milieu. This re-conceptualization illuminates several issues in cognitive and clinical neuroscience with implications for experiences of selfhood and emotion. We first contextualize interoception in terms of active (Bayesian) inference in the brain, highlighting its enactivist (embodied) aspects. We then consider the key role of uncertainty or precision and how this might translate into neuromodulation. We next examine the implications for understanding the functional anatomy of the emotional brain, surveying recent observations on agranular cortex. Finally, we turn to theoretical issues, namely, the role of interoception in shaping a sense of embodied self and feelings. We will draw links between physiological homoeostasis and allostasis, early cybernetic ideas of predictive control and hierarchical generative models in predictive processing. The explanatory scope of interoceptive inference ranges from explanations for autism and depression, through to consciousness. We offer a brief survey of these exciting developments.

This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’.

Alexithymia, not autism, is associated with impaired interoception

It has been proposed that Autism Spectrum Disorder (ASD) is associated with difficulties perceiving the internal state of one's body (i.e., impaired interoception), causing the socio-emotional deficits which are a diagnostic feature of the condition. However, research indicates that alexithymia - characterized by difficulties in recognizing emotions from internal bodily sensations - is also linked to atypical interoception. Elevated rates of alexithymia in the autistic population have been shown to underpin several socio-emotional impairments thought to be symptomatic of ASD, raising the possibility that interoceptive difficulties in ASD are also due to co-occurring alexithymia. Following this line of inquiry, the present study examined the relative impact of alexithymia and autism on interoceptive accuracy (IA). Across two experiments, it was found that alexithymia, not autism, was associated with atypical interoception. Results indicate that interoceptive impairments should not be considered a feature of ASD, but instead due to co-occurring alexithymia.