Alexithymia, not autism, is associated with impaired interoception

Atypical interoception as a common risk factor for psychopathology: A review

The inadequacy of a categorial approach to mental health diagnosis is now well-recognised, with many authors, diagnostic manuals and funding bodies advocating a dimensional, trans-diagnostic approach to mental health research. Variance in interoception, the ability to perceive one's internal bodily state, is reported across diagnostic boundaries, and is associated with atypical functioning across symptom categories. Drawing on behavioural and neuroscientific evidence, we outline current research on the contribution of interoception to numerous cognitive and affective abilities (in both typical and clinical populations), and describe the interoceptive atypicalities seen in a range of psychiatric conditions. We discuss the role that interoception may play in the development and maintenance of psychopathology, as well as the ways in which interoception may differ across clinical presentations. A number of important areas for further research on the role of interoception in psychopathology are highlighted.

Alexithymia and Autistic Traits: Associations With Social and Emotional Challenges Among College Students

Background: Alexithymia is a multifaceted personality construct defined by marked difficulties in identifying and describing feelings and in externally oriented thinking. Given its intrinsic role in social-emotional processing, alexithymia is now recognized as a trans-diagnostic trait in a range of neurodevelopmental disorders, including autism. Research has pinpointed to the co-occurrence of autism with characteristics typical of alexithymic normative samples, such as social-communication difficulties and decreased emotion regulation abilities. Nonetheless, the role of individual facets of alexithymia in predicting challenges in social communication functioning is still understudied. Methods: In total, 275 young adults completed the Toronto Alexithymia Scale, the Autism Spectrum Quotient (short form), the Interpersonal Competence Questionnaire, and the Difficulties in Emotion Regulation Scale self-reported questionnaires for assessing alexithymic and autistic traits, social-communication abilities, and emotion regulation difficulties. We used regression models to establish cross-sectional associations between autism, alexithymia, and social-emotional difficulties. Also, we ran a parallel mediation analysis to determine whether the relationship between autistic traits and emotion regulations challenges are mediated by Alexithymia facets. Results: Analysis showed a significant positive association between autistic traits and alexithymic traits and between autistic traits and emotion regulation difficulties while, as expected, autistic traits were negatively correlated with social skills. A significant relationship was found among the participants' levels of alexithymia and their interpersonal skills with two of three alexithymic subscales significantly contributing to the model. Similarly, a significant relationship was found among alexithymia subscales and emotion regulation difficulties with all three alexithymia subscales being statistically significant. Finally, analysis on two mediator models indicated a significant effect of autistic traits on social skills mediated by alexithymic traits as well as a significant indirect effect of autistic traits on emotion regulation difficulties mediated by alexithymic traits. Conclusion: The results of this study provide evidence of the influence of different alexithymic facets on the relationship between autistic traits and social-emotional challenges in young adults. Longitudinal studies may explore further alexithymia and its associations with social-emotional difficulties in autism as well as the potential implications of these findings in intervention and treatment programs.

Interoceptive Accuracy as a Function of Hypnotizability

This study aimed to measure the interoceptive accuracy (IA) of individuals with high (highs), medium (mediums), and low hypnotizability (lows) through the heartbeat-counting task during 3 relaxation trials. Participants completed the Multidimensional Assessment of Interoceptive Awareness (MAIA), ECG and skin conductance (SC) were monitored, and the experienced difficulty in counting was reported. Results showed similar counting difficulty and number of actual heartbeats in highs, mediums, and lows. SC decreased in highs during all trials, in mediums and lows only in the third trial. IA measured as [1 - (ǀrecorded heartbeats-counted heartbeatsǀ)/recorded heartbeats] was negatively correlated with hypnotizability and not correlated with interoceptive sensitivity (IS) measured by MAIA scales. Among mediums, IA was higher in males than in females.

Weaker implicit interoception is associated with more negative body image: Evidence from gastric-alpha phase amplitude coupling and the heartbeat evoked potential

Interoception refers to the processing of internal bodily stimuli, while body image refers to appearance-related perceptions, affect, and cognitions. Previous research has found that body image is associated with self-reported and behavioural indices of interoception. Here, we extended this research by examining associations between measures of positive (i.e., body appreciation, functionality appreciation) and negative body image (i.e., body shame, weight preoccupation) and two electrophysiological indices of interoceptive processing, namely the heartbeat evoked potential (HEP) and gastric-alpha phase-amplitude coupling (PAC), in a sample of 36 adults. Significant negative associations were identified between the indices of negative body image and the interoception variables. Specifically, more negative HEP amplitude and lower gastric-alpha PAC were both associated with greater body shame and weight preoccupation. However, no significant associations were identified for the indices of positive body image. These findings extend previous work by demonstrating that there are significant associations between negative body image and previously unexplored components of cardiac and gastric interoception. This, in turn, could have important clinical applications, such as the HEP and gastric-alpha PAC both serving as biomarkers of negative body image.

Autism, music and Alexithymia: A musical intervention to enhance emotion recognition in adolescents with ASD

BACKGROUND

Difficulties identifying and describing emotions in Autism Spectrum Disorder (ASD) have been linked with an increased prevalence of Type 2 Alexithymia. Alexithymia is associated with difficulties in interpreting and verbally labelling physiological arousal. Children and adults with ASD show typical patterns of physiological arousal to music and can attribute verbal labels to musical emotions.

AIM

This pilot study aimed to develop a music-based intervention to improve facial and vocal emotion recognition (ER) and Alexithymia in adolescents with ASD.

METHODS AND PROCEDURES

Adolescents with ASD completed 5 music sessions and pre and post-tests of Alexithymia, ER and language. Each intervention began with a researcher-led group analysis of the emotions expressed in a series of musical excerpts, followed by a group-led discussion of the participants' experiences of these emotions and the ways they may be communicated. Finally, the likely causes and outward expression of these emotions were discussed.

OUTCOME AND RESULTS

Results showed that at pre-test, chronological age (CA) and receptive vocabulary were significantly associated with recognition of facial and verbal emotions and Not hiding emotions. At post-test, older children showed a greater increase in recognition of voices and in emotional bodily awareness. Correlations suggested a trend towards increased ER in voices and faces in children with lower language scores.

CONCLUSIONS AND IMPLICATIONS

Music-based interventions may enhance ER in adolescents with ASD and Alexithymia. Limitations and recommendations for future investigations are discussed.

Relationship between interoceptive sensibility and somatoform disorders in adults with autism spectrum traits. The mediating role of alexithymia and emotional dysregulation

OBJECTIVE

The purpose of the study is to analyses the relationship between interoceptive sensibility and somatoform disorders among persons with Autism Spectrum Disorder (ASD). It has been assumed that the interoceptive sensibility is accompanied by a high level of alexithymia and emotion dysregulation in somatoform disorders.

METHODS

Persons under the care of the foundation helping people with ASD were asked to participate in the study. In total, 205 people took part in the research. The participants aged from 18 to 63 (M = 34.91; SD = 8.44). The ASD group comprised 79 persons (38.5% of subjects). The control group comprised 126 individuals (61.5% of subjects). Participants completed self-report questionnaires measuring autism (AQ), interoceptive sensibility (BPQ), alexithymia (TAS20), emotional dysregulation (DERS), and somatoform disorder (SDQ).

RESULTS

The analyses showed a moderation effect of the group, which indicates the existence of a relationship between interoceptive sensibility and somatoform disorders to the greater extent in the clinical group than in the control group. In addition, the serial multiple mediation model analysis allowed to verify the mediating effect of emotion dysregulation and alexithymia on the abovementioned relationship. The indirect effect, which assumed the mediating role of alexithymia turned out to be significant, contrary to the indirect effect where emotion dysregulation was a mediator in a situation where both variables were applied simultaneously.

CONCLUSIONS

Interoceptive sensibility correlated with level of alexithymia, in particular, difficulties in identifying and verbalizing emotions and emotion dysregulation in the lack of emotional awareness and lack of emotional clarity and is associated with somatoform disorders in the investigated group regardless of participants' belonging to the ASD or control group.

On the construct validity of interoceptive accuracy based on heartbeat counting: Cardiovascular determinants of absolute and tilt-induced change scores

Interoceptive accuracy (IAcc) as assessed with the heartbeat counting task (IAcc_HBCT) may be affected by a range of factors including (1.) the ability to adequately detect cardiac signals, indicated by IAcc in a heartbeat discrimination task (IAcc_HBDT), (2.) cardiac signal properties, affected by sympathetic and parasympathetic tone, and (3.) non-interoceptive processes, including time estimation accuracy (TEAcc). In the current study we investigated the contribution of these factors to absolute and Δ IAcc_HBCT scores, induced by passive head-up and head-down tilt in 49 healthy individuals. A set of hierarchical regression models showed IAcc_HBDT scores as the strongest and, across different orthostatic (tilt) conditions, most stable (positive) predictor of absolute and Δ IAcc_HBCT scores. Neither indicators of cardiac signal properties (except for HR in head-down-tilt), nor TEAcc predicted absolute or Δ IAcc_HBCT scores. These findings support the convergent and discriminant validity of absolute and Δ IAcc_HBCT scores.

Measuring interoception: The phase adjustment task

Interoception, perception of one's bodily state, has been associated with mental health and socio-emotional processes. However, several interoception tasks are of questionable validity, meaning associations between interoception and other variables require confirmation with new measures. Here we describe the novel, smartphone-based Phase Adjustment Task (PAT). Tones are presented at the participant's heart rate, but out of phase with heartbeats. Participants adjust the phase relationship between tones and heartbeats until they are synchronous. Data from 124 participants indicates variance in performance across participants which is not affected by physiological or strategic confounds. Associations between interoception and anxiety, depression and stress were not significant. Weak associations between interoception and mental health variables may be a consequence of testing a non-clinical sample. A second study revealed PAT performance to be moderately stable over one week, consistent with state effects on interoception.

Diseases, Disorders, and Comorbidities of Interoception

Interoception, the sense of the body's internal physiological state, underpins homeostatic reflexes, motivational states, and sensations contributing to emotional experiences. The continuous nature of interoceptive processing, coupled to behavior, is implicated in the neurobiological construction of the sense of self. Aberrant integration and control of interoceptive signals, originating in the brain and/or the periphery, can perturb the whole system. Interoceptive abnormalities are implicated in the pathophysiology of psychiatric disorders and in the symptomatic expression of developmental, neurodegenerative, and neurological disorders. Moreover, interoceptive mechanisms appear central to somatic disorders of brain-body interactions, including functional digestive disorders, chronic pain, and comorbid conditions. The present article provides an overview of disorders of interoception and suggests future directions for better understanding, diagnosis, and management of these disorders.

Improving the measurement of alexithymia in autistic adults: a psychometric investigation of the 20-item Toronto Alexithymia Scale and generation of a general alexithymia factor score using item response theory

BACKGROUND

Alexithymia, a personality trait characterized by difficulties interpreting emotional states, is commonly elevated in autistic adults, and a growing body of literature suggests that this trait underlies several cognitive and emotional differences previously attributed to autism. Although questionnaires such as the 20-item Toronto Alexithymia Scale (TAS-20) are frequently used to measure alexithymia in the autistic population, few studies have investigated the psychometric properties of these questionnaires in autistic adults, including whether differential item functioning (I-DIF) exists between autistic and general population adults.

METHODS

This study is a revised version of a previous article that was retracted due to copyright concerns (Williams and Gotham in Mol Autism 12:1-40). We conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 cognitively able autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in a large international psychological study. The factor structure of the TAS-20 was examined using confirmatory factor analysis, and item response theory was used to generate a subset of the items that were strong indicators of a "general alexithymia" factor. Correlations between alexithymia and other clinical outcomes were used to assess the nomological validity of the new alexithymia score in the SPARK sample.

RESULTS

The TAS-20 did not exhibit adequate model fit in either the autistic or general population samples. Empirically driven item reduction was undertaken, resulting in an 8-item general alexithymia factor score (GAFS-8, with "TAS" no longer referenced due to copyright) with sound psychometric properties and practically ignorable I-DIF between diagnostic groups. Correlational analyses indicated that GAFS-8 scores, as derived from the TAS-20, meaningfully predict autistic trait levels, repetitive behaviors, and depression symptoms, even after controlling for trait neuroticism. The GAFS-8 also presented no meaningful decrement in nomological validity over the full TAS-20 in autistic participants.

LIMITATIONS

Limitations of the current study include a sample of autistic adults that was majority female, later diagnosed, and well educated; clinical and control groups drawn from different studies with variable measures; only 16 of the TAS-20 items being administered to the non-autistic sample; and an inability to test several other important psychometric characteristics of the GAFS-8, including sensitivity to change and I-DIF across multiple administrations.

CONCLUSIONS

These results indicate the potential of the GAFS-8 to robustly measure alexithymia in both autistic and non-autistic adults. A free online score calculator has been created to facilitate the use of norm-referenced GAFS-8 latent trait scores in research applications (available at https://asdmeasures.shinyapps.io/alexithymia ).

Development and Psychometric Properties of a New Questionnaire to Assess Mental Health and Concerning Behaviors in Children and Young People with Autism Spectrum Disorder (ASD): The Assessment of Concerning Behavior (ACB) Scale

Although 70% of autistic children and young people meet criteria for co-occurring psychiatric conditions, there are few screening measures specifically for autistic individuals. We describe the development and validation of the Assessment of Concerning Behavior (ACB), an instrument co-developed with the autistic community to assess mental health and problematic/risky behaviors. Items include descriptions to facilitate symptom recognition by autistic people, and carers/professionals. The ACB was completed by 255 parents, 149 autistic children and young people and 30 teachers. Internal consistency, stability and validity was assessed. The ACB parent-version fit a two-factor model (internalizing and externalizing problems) and showed adequate test-retest reliability, internal consistency and construct validity. The ACB is a promising new measure for research and clinical use in autism.

A Developmental Framework for Embodiment Research: The Next Step Toward Integrating Concepts and Methods

Embodiment research is at a turning point. There is an increasing amount of data and studies investigating embodiment phenomena and their role in mental processing and functions from across a wide range of disciplines and theoretical schools within the life sciences. However, the integration of behavioral data with data from different biological levels is challenging for the involved research fields such as movement psychology, social and developmental neuroscience, computational psychosomatics, social and behavioral epigenetics, human-centered robotics, and many more. This highlights the need for an interdisciplinary framework of embodiment research. In addition, there is a growing need for a cross-disciplinary consensus on level-specific criteria of embodiment. We propose that a developmental perspective on embodiment is able to provide a framework for overcoming such pressing issues, providing analytical tools to link timescales and levels of embodiment specific to the function under study, uncovering the underlying developmental processes, clarifying level-specific embodiment criteria, and providing a matrix and platform to bridge disciplinary boundaries among the involved research fields.

Objective and Subjective Measurement of Alexithymia in Adults with Autism

High rates of alexithymia, a condition characterised by difficulties identifying and describing emotions, are frequently reported in both children and adults with autism spectrum disorder (ASD). However, the dilemma of measuring alexithymia via self-report has rarely been addressed. In this study, we compared objective and subjective measures of alexithymia in adults with ASD and typically developing adults. We found significantly higher levels of alexithymia in the ASD sample as measured by both self-report on the Toronto Alexithymia Scale (TAS-20) and by the observer rated Alexithymia Provoked Response Scale (APRQ). However, the two measures did not correlate with each other. We explore the different facets of the alexithymia construct that these two measures may be distinguishing.

Disentangling interoceptive abilities in alexithymia

In recent years, research on interoceptive abilities (i.e., sensibility, accuracy, and awareness) and their associations with emotional experience has flourished. Yet interoceptive abilities in alexithymia—a personality trait characterized by a difficulty in the cognitive interpretation of emotional arousal, which impacts emotional experience—remain under-investigated, thereby limiting a full understanding of subjective emotional experience processing. Research has proposed two contrasting explanations thus far: in one model, the dimensions of interoceptive sensibility and accuracy in alexithymia would increase; in the other model, they would decrease. Surprisingly, the contribution of interoceptive awareness has been minimally researched. In this study (N = 182), the relationship between participants’ level of alexithymia and the three interoceptive dimensions was tested. Our results show that the higher the level of alexithymia is, the higher interoceptive accuracy and sensibility (R² = 0.29 and R² = 0.14); conversely, the higher the level of alexithymia is, the lower interoceptive awareness (R² = 0.36). Moreover, an ROC analysis reveals that interoceptive awareness is the most accurate predictor of alexithymia, yielding over 92% accuracy. Collectively, these results support a coherent understanding of interoceptive abilities in alexithymia, whereby the dissociation of interoceptive accuracy and awareness may explain the underlying psycho-physiological mechanisms of alexithymia. A possible neurocognitive mechanism is discussed which suggests insurgence of psychosomatic disorders in alexithymia and related psychotherapeutic approaches.

Are Autistic and Alexithymic Traits Distinct? A Factor-Analytic and Network Approach

Despite the heterogeneity in autism, socioemotional difficulties are often framed as universal. Increasing evidence, however, suggests that socioemotional difficulties may be explained by alexithymia, a distinct yet frequently co-occurring condition. If, as some propose, autistic traits are responsible for socioemotional impairments, then alexithymia may itself be a symptom of autism. We aimed to determine whether alexithymia should be considered a product of autism or regarded as a separate condition. Using factor-analytic and network approaches, we provide evidence that alexithymic and autistic traits are distinct. We argue that: (1) models of socioemotional processing in autism should conceptualise difficulties as intrinsic to alexithymia; and (2) assessment of alexithymia is crucial for diagnosis and personalised interventions.

Underlying Thinking Pattern Profiles Predict Parent-Reported Distress Responses in Autism Spectrum Disorder

Appreciating autistic neurodiversity is important when supporting autistic people who experience distress. Specifically, use of a profiling model can reveal less visible autistic differences, including strengths and abilities. Binary logistic regressions showed that the likelihood of extreme distress responses could be interpreted based on parent-reported autistic thinking pattern profiles for 140 young people. Perspective-taking (specifically empathy), extreme demand avoidance, and over-sensory sensitivity each contributed to the combined regression models. From the clinical perspective of autism as a multi-dimensional and inter-connected construct, there may be implications for planning support and building positive self-understanding. Individually tailored adjustments and support strategies may be identified more easily after delineating variables found across four core aspects: sensory coherence, flexible thinking, perspective-taking, and regulation.

The inside of me: interoceptive constraints on the concept of self in neuroscience and clinical psychology

Humans are unique in their ability to think about themselves and carry a more or less clear notion of who they are in their mind. Here we review recent evidence suggesting that the birth, maintenance, and loss of the abstract concept of 'self' is deeply tied to interoception, the sense of internal physiological signals. Interoception influences multiple facets of the self-concept, cutting across its material, social, moral, and agentive components. Overall, we argue that interoception contributes to the stability of the self-concept over time, unifying its layers and constraining the degree to which it is susceptible to external influences. Hence, the core features of the self-concept are those that correlate more with inner bodily states. We discuss the implications that this may have for theories of embodied cognition as well as for the understanding of psychiatric disorders in which the concept of self appears fragmented or loose. Finally, we formulate some empirical predictions that could be tested in future studies to shed further light on this emerging field.

Evidence toward the potential absence of relationship between temporal and spatial heartbeats perception

Many interoceptive tasks (i.e. measuring the sensitivity to bodily signals) are based upon heartbeats perception. However, the temporal perception of heartbeats-when heartbeats are felt-varies among individuals. Moreover, the spatial perception of heartbeats-where on the body heartbeats are felt-has not been characterized in relation to temporal. This study used a multi-interval heartbeat discrimination task in which participants judged the timing of their own heartbeats in relation to external tones. The perception of heartbeats in both time and spatial domains, and relationship between these domains was investigated. Heartbeat perception occurred on average ~ 250 ms after the ECG R-wave, most frequently sampled from the left part of the chest. Participants' confidence in discriminating the timing of heartbeats from external tones was maximal at 0 ms (tone played at R-wave). Higher confidence was related to reduced dispersion of sampling locations, but Bayesian statistics indicated the absence of relationship between temporal and spatial heartbeats perception. Finally, the spatial precision of heartbeat perception was related to state-anxiety scores, yet largely independent of cardiovascular parameters. This investigation of heartbeat perception provides fresh insights concerning interoceptive signals that contribute to emotion, cognition and behaviour.

Individual differences in sensory and expectation driven interoceptive processes: a novel paradigm with implications for alexithymia, disordered eating and obesity

Those with disordered eating and/or obesity often express difficulties in sensing or interpreting what is happening in the body (interoception). However, research is hindered by conceptual confusion, concerns surrounding domain specificity, and an inability to distinguish sensory (bottom-up) and expectation driven (top-down) interoceptive processes. A paradigm was therefore developed from an active inference perspective. Novel indices were computed and examined in those with alexithymia: a personality associated with interoceptive deficits and disordered eating. The paradigm successfully identified individuals driven by sensations rather than expectations: alexithymia was characterized by attenuated prior precision (a larger divergence between pre-prandial and post-prandial satiety, and low expectation confidence), and increased prediction error (a higher correlation between changes in hunger and blood glucose, and greater rebound hunger after a sensory incongruent drink). In addition, those with a higher BMI were less confident and had a larger anticipated satiety divergence. These findings demonstrate the need to move beyond existing paradigms such as the Satiety Quotient and Heartbeat Counting Task which may have limited our understanding of eating behaviour.

Transcranial direct current stimulation for empathy: A systematic review and meta-analysis

Transcranial Direct Current Stimulation (tDCS) has been used to modulate empathy, but no studies have meta-analyzed the evidence base for its efficacy. This study aimed to determine the efficacy of tDCS at modulating empathy. We conducted a systematic review and meta-analysis of randomized controlled trials involving anodal or cathodal versus sham tDCS to modulate empathy in healthy adults and clinical populations. Random-effects modelling was applied to pooling overall efficacy estimates using standardized mean differences (Hedge's g) and 95% confidence intervals. Outcome measures for tasks designed to measure empathy were reaction time and accuracy. Anodal tDCS appears to improve lab-based computerized measures of cognitive empathy in healthy adult volunteers. While the evidence provided by this review may be of relevance to individuals with impaired empathic capabilities, the generalizability of our findings is geared towards nonclinical populations given the preponderance of healthy volunteers in our review. Hence, it is not clear if moderate improvements in speed and accuracy on lab-based computerized empathy measures would lead to meaningful clinical improvements. Future studies should consider the use of tDCS to modulate empathy in clinical populations.

Improving the measurement of alexithymia in autistic adults: a psychometric investigation and refinement of the twenty-item Toronto Alexithymia Scale

BACKGROUND

Alexithymia, a personality trait characterized by difficulties interpreting one's own emotional states, is commonly elevated in autistic adults, and a growing body of literature suggests that this trait underlies a number of cognitive and emotional differences previously attributed to autism, such as difficulties in facial emotion recognition and reduced empathy. Although questionnaires such as the twenty-item Toronto Alexithymia Scale (TAS-20) are frequently used to measure alexithymia in the autistic population, few studies have attempted to determine the psychometric properties of these questionnaires in autistic adults, including whether differential item functioning (I-DIF) exists between autistic and general population adults.

METHODS

We conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 verbal autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in a large international psychological study (the Human Penguin Project). The factor structure of the TAS-20 was examined using confirmatory factor analysis, and item response theory was used to further refine the scale based on local model misfit and I-DIF between the groups. Correlations between alexithymia and other clinical outcomes such as autistic traits, anxiety, and quality-of-life were used to assess the nomological validity of the revised alexithymia scale in the SPARK sample.

RESULTS

The TAS-20 did not exhibit adequate global model fit in either the autistic or general population samples. Empirically driven item reduction was undertaken, resulting in an eight-item unidimensional scale (TAS-8) with sound psychometric properties and practically ignorable I-DIF between diagnostic groups. Correlational analyses indicated that TAS-8 scores meaningfully predict autistic trait levels, anxiety and depression symptoms, and quality of life, even after controlling for trait neuroticism.

LIMITATIONS

Limitations of the current study include a sample of autistic adults that was overwhelmingly female, later-diagnosed, and well-educated; clinical and control groups drawn from different studies with variable measures; and an inability to test several other important psychometric characteristics of the TAS-8, including sensitivity to change and I-DIF across multiple administrations.

CONCLUSIONS

These results indicate the potential of the TAS-8 as a psychometrically robust tool to measure alexithymia in both autistic and non-autistic adults. A free online score calculator has been created to facilitate the use of norm-referenced TAS-8 latent trait scores in research applications (available at http://asdmeasures.shinyapps.io/TAS8_Score ).

Interoception and stress in patients with Functional Neurological Symptom Disorder

INTRODUCTION

Research suggests that patients with Functional Neurological Symptom Disorder (pwFND) struggle to identify their own emotions and associated physiological cues (interoceptive sensitivity, IS). However, it is not known how this deficit interacts with stress. This study aimed to assess IS in pwFND at baseline and following stress induction, and relate the findings to self-reported emotion processing difficulties.

METHODS

Twenty-six pwFND and 27 healthy controls performed the Heart Beat Detection Task pre- and post-stress induction with the Cold Pressor Test. Participants also completed questionnaires assessing anxiety (GAD-7) and depressive symptomology (PHQ-9), as well as emotion processing (EPS-25).

RESULTS

Patients reported deficits in emotion processing (p < . 001) and had lower IS (p = .032) than healthy controls. IS improved following stress induction across both groups (p = .003) but patients' IS was lower than that of healthy controls' pre-and post-stress induction. Exploratory analyses revealed that patients reporting sensory symptoms had lower IS at baseline than patients who did not.

CONCLUSION

Our findings suggest that pwFND are relatively impaired in the identification of their emotions at baseline and following stress induction. This may be related to the experience of functional sensory symptoms and has implications for the psychological treatment of emotion dysregulation in this population.

Alexithymia is related to poor social competence in autistic and nonautistic children

Alexithymia is characterized by difficulties identifying and describing one's own emotions and the emotions of others. These challenges with understanding emotions in people with alexithymia may give rise to difficulties with social interactions. Given that alexithymia frequently co-occurs with autism spectrum disorder (ASD), and that both populations have difficulties with social interactions, it is of interest to determine whether alexithymia can help to parse some of the heterogeneity in social competence in autistic and nonautistic individuals. The caregivers of 241 children (6-14 years old), including 120 autistic, and 121 nonautistic, rated their child's social competence using the Multidimensional Social Competence Scale (MSCS), autism traits using the Autism Spectrum Quotient (AQ), and alexithymia traits using the Children's Alexithymia Measure (CAM). Regression analyses indicated that age, IQ, sex, AQ, and CAM scores accounted for 40.2% of the variance in autistic children's, and 68.2% of the variance in nonautistic children's, parent-reported social competence. Importantly, after controlling for age, IQ, sex, and AQ scores, CAM scores alone accounted for an additional 16.2% of the variance in autistic children's, and 17.4% of the variance in nonautistic children's social competence. These results indicate that higher alexithymia traits predict lower levels of social competence, suggesting that increased difficulty in identifying and describing one's own emotions and the emotions of others is associated with poorer social competence. Furthermore, CAM scores were found to partially mediate the relationship between autistic traits and social competence, suggesting that comorbid alexithymia traits may be partially responsible for poor social competence in individuals with high autistic traits. This research contributes to the understanding of the factors associated with the development of social competence and highlights alexithymia as a potential target for identification and intervention to improve social competence. LAY SUMMARY: Alexithymia is a condition where people find it hard to think and talk about their (and others') feelings. About 50% of autistic people have alexithymia. This might be why they have social and emotional difficulties. Parents answered questions about alexithymia and social difficulties their children have. Children with more alexithymia problems had poorer social skills. Thus, alexithymia may be related to social problems faced by autistic and nonautistic children.

On the Relationship of Interoceptive Accuracy and Attention: A Controlled Study With Depressed Inpatients and a Healthy Cohort

Objective

Previous research has shown reduced interoceptive accuracy (IAcc) in depression. Attention deficit represents a key symptom of depression. Moreover, IAcc is positively correlated with attention. There is no study that investigates the effect of depression on IAcc and attention. The aim of this study is to examine the mediating effect of IAcc on depression and attention.

Methods

Thirty-six depressed patients from the Psychosomatic Clinic in Windach were matched with 36 healthy controls according to age and sex and were assessed at Ulm University. All participants completed the Beck Depression Inventory-II, the heartbeat perception task to examine IAcc, and the d2 test assessing selective attention.

Results

Depressed patients showed attention deficits—both for general visual attention and IAcc—compared to healthy controls. The mediation analyses revealed that the relationship between depression and attention is not mediated via IAcc. Furthermore, depression predicts IAcc and attention, but these effects are direct and largely unaffected by the respective other variable.

Discussion

The results of the present study highlight both interoceptive as well as attention deficits in depressed patients. No clear mediation between these variables could be shown in this study. More elaborative research is needed to clarify whether different approaches to improve IAcc are effective for these deficits in depressed patients and could therefore be of importance as an additional aspect of therapy in depression.

How Closely Related Are Parent and Child Reports of Child Alexithymia?

Alexithymia is a subclinical trait involving difficulty describing and identifying emotions. It is common in a number of psychiatric conditions. Alexithymia in children is sometimes measured by parent report and sometimes by child self-report, but it is not yet known how closely related the two measures are. This is an important question both theoretically and practically, in terms of research design and clinical practice. We conducted a preliminary study to investigate this question in a sample of 6- to 11-year-old neurotypical children and their parents (N = 29 dyads). Parent and child reports were not correlated, and 93% of parents under-estimated their child’s level of alexithymia relative to the child’s self-report. Based on these results, we hypothesize that when asked to report on the child’s alexithymia, children and parents may not be reporting on the same phenomenon, and thus these two measures may not be interchangeable. These provocative findings, however, must be considered preliminary: our analyses were sufficiently powered to detect a strong relation between the two types of report had one existed, but our analyses were not sufficiently powered to distinguish between a small relation and no relation at all.

Autonomic dysfunction in autism: The roles of anxiety, depression, and stress

Autism spectrum disorder (ASD) is associated with atypical autonomic nervous system (ANS) function. However, little is known about this relationship, while accounting for co-occurring mental health conditions (e.g. anxiety) that are also associated with ANS dysfunction. In addition, research on the ANS has typically involved physiological measurements, without using more clinically meaningful measures of ANS dysfunction, such as the self-reported frequency of ANS-related physical health symptoms. Furthermore, very little is known about ANS function in autistic adults, given that previous research has focused on ANS dysfunction in children with ASD. Addressing these gaps in the literature, we compared ANS function in adults with(out) ASD (Study 1). Although autistic adults reported greater ANS dysfunction than matched neurotypical controls, this difference was not significant after controlling for anxiety and depression. Similarly, in a large nonclinical sample (Study 2), we found that anxiety and stress mediated the relationship between autistic traits and ANS dysfunction. Together, we conclude that ANS dysfunction is not a feature of ASD per se, but instead attributable to the high levels of anxiety and stress in autistic adults. We discuss the clinical relevance of these findings for managing ANS dysfunction and other physical and mental health concerns in autistic adulthood.

Lay abstract

The autonomic nervous system (ANS) is responsible for the functioning of the heart, bladder, pupils and several other bodily functions. Therefore, when the ANS functions abnormally, individuals can experience a number of physical symptoms, including dizziness, abnormal sweating and digestive difficulties. Currently, it is unclear if autistic adults experience ANS dysfunction. Therefore, in this study, we investigated whether autistic adults report more ANS-related physical symptoms, indicating greater ANS dysfunction, and whether this may be related to autism, or rather anxiety, depression, or stress. The findings suggest that ANS dysfunction, where found in autism, is due to co-occurring stress and anxiety. We therefore propose that treating stress and anxiety may be an effective way to ameliorate ANS-related health problems in autistic adults.

Interoception moderates the relation between alexithymia and risky-choices in a framing task: A proposal of two-stage model of decision-making

Decision-making depends on the context (frame) in which questions and alternatives are presented. Moreover, research has showed that the ability to detect bodily sensations (interoception) and being able to attribute these changes to emotions correctly (alexithymia) influence how we make decisions. The aim of the present research was to study how interoception and alexithymia might affect the Framing effect (FE), a cognitive bias closely related to emotional system. 42 healthy participants completed the Risky-choice Framing task and their interoception and alexithymia levels were measured. Results showed that the participants were more risk-taking under the negative frames in comparison to the positive ones. In addition, we found that alexithymia and interoception were negatively and positively correlated with the FE, respectively. Finally, the moderation analyses revealed that alexithymia predicted a lower FE only when the interoception was high. Based on previous literature and in our results, we propose a two-stage model of intuitive decision-making.

Reduced differentiation of emotion-associated bodily sensations in autism

LAY ABSTRACT

More research has been conducted on how autistic people understand and interpret other people's emotions, than on how autistic people experience their own emotions. The experience of emotion is important however, because it can relate to difficulties like anxiety and depression, which are common in autism. In neurotypical adults and children, different emotions have been associated with unique maps of activity patterns in the body. Whether these maps of emotion are comparable in autism is currently unknown. Here, we asked 100 children and adolescents, 45 of whom were autistic, to color in outlines of the body to indicate how they experienced seven emotions. Autistic adults and children sometimes report differences in how they experience their internal bodily states, termed interoception, and so we also investigated how this related to the bodily maps of emotion. In this study, the autistic children and adolescents had comparable interoception to the non-autistic children and adolescents, but there was less variability in their maps of emotion. In other words, they showed more similar patterns of activity across the different emotions. This was not related to interoception, however. This work suggests that there are differences in how autistic people experience emotion that are not explained by differences in interoception. In neurotypical people, less variability in emotional experiences is linked to anxiety and depression, and future work should seek to understand if this is a contributing factor to the increased prevalence of these difficulties in autism.

Heart Rate Variability Modulates Interoceptive Accuracy

Our emotional experiences depend on our interoceptive ability to perceive and interpret changes in our autonomous nervous system. An inaccurate perception and interpretation of autonomic changes impairs our ability to understand and regulate our emotional reactions. Impairments in emotion understanding and emotion regulation increase our risk for mental disorders, indicating that interoceptive deficits play an important role in the etiology and pathogenesis of mental disorders. We, thus, need measures to identify those of us whose interoceptive deficits impair their emotion understanding and emotion regulation. Here, we used cardiac measures to investigate how our ability to engage prefrontal and (para-)limbic brain region regions affects our ability to perceive and interpret cardiac changes. We administered a heartbeat detection task to a sample of healthy individuals (n = 113) whose prefrontal-(para-) limbic engagement had been determined on basis of a heart rate variability recording. We found a positive association between heartbeat detection and heart rate variability, implying that individuals with higher heart rate variability were more accurate in heartbeat detection than individuals with lower heart rate variability. These findings suggest that our interoceptive accuracy depends on our prefrontal-(para-)limbic engagement during the perception and interpretation of cardiac changes. Our findings also show that cardiac measures may be useful to investigate the association between interoceptive accuracy and prefrontal-(para-)limbic engagement in a time- and cost-efficient manner.

Linking perception of bodily states and cognitive control: the role of interoception in impulsive behaviour

Interoception and impulsivity are two multi-dimensional constructs and although the role of interoception in impulsiveness has been previously reported, it is not clear whether their different facets are related to each other. In the present study, we aimed at bridging this gap by investigating the relationships between interoception and impulsivity in the light of their multi-dimensional nature. To this aim, we conducted a cross-task comparison and assessed in the same sample of healthy participants, interoceptive accuracy, by the heartbeat perception task, interoceptive sensibility, by a self-reported measure, "hot" impulsivity, by a behavioural task of risk taking, and "cool" impulsivity, by a go/no-go task. Also, we assessed trait impulsivity by a self-report measure. We found that interoceptive sensibility contributed to "hot" impulsivity, while interoceptive accuracy was related to non-planning trait impulsivity. These findings underscore the need to investigate at a finer grain the relationships between these two complex, multi-dimensional constructs.

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.

Frontotemporal Dementia: A Window to Alexithymia

Alexithymia is pervasive among psychiatric patients, but its neurobiological mechanism is unclear. Patients with alexithymia cannot "read emotions," a process involving interoception, or the perception of the body's internal state, primarily in the insulae. The frontotemporal dementias are also associated with inability to correctly read emotions; hence, these dementias can provide a window into the mechanism of alexithymia. Patients with behavioral variant frontotemporal dementia (bvFTD) have a weak emotional signal with impaired emotional recognition, hypoemotionality, and decreased physiological arousal. bvFTD affects the insulae, and the weak emotional signal facilitates impaired interoceptive accuracy, resulting in an overreliance on cognitive appraisal rather than on internal sensations. In contrast, patients with semantic dementia, another frontotemporal dementia syndrome, can have intact interoception, but they have disturbed cognitive appraisal of the meaning of their bodily sensations. This "alexisomia" in semantic dementia can lead to misinterpreted somatic symptoms. Together, the findings in alexithymic patients and frontotemporal dementia syndromes support the model of impaired interoceptive accuracy as the mechanism of alexithymia, possibly from dysfunction in the insulae.

Interoception and alexithymia are related to differences between the self-reported and the objectively measured physical activity in patients with chronic musculoskeletal pain

OBJECTIVE

Patients with chronic musculoskeletal pain (CMP) have difficulty estimating their level of physical activity (PA). Factors associated with this difficulty have yet to be identified; however, identification could allow for increased accuracy in large-scale PA surveys, and enhanced self-management. The purpose of this study was to determine the relationship of interoception and alexithymia with differences between self-reported and objectively measured PA, and investigate factors as they relate to accurately self-reporting PA.

METHODS

A cross-sectional survey of 33 patients with CMP and 32 healthy individuals was conducted from July 2018 to June 2019. We measured differences in Moderate to Vigorous Physical Activity (D-MVPA) using an accelerometer and self-report. A heartbeat tracking task (HTT) was used to measure interoception, and alexithymia was measured using the 20-item Toronto Alexithymia Scale (TAS-20).

RESULTS

The CMP group (median 43.5 min/day, IQR 20.6-77.6) showed significantly higher D-MVPA values than the control group (median 22.5 min/day, IQR 6.7-34.9) (p < .001). In patients with CMP, D-MVPA positively correlated with TAS-20 (rho = 0.470, p = .006) and correlated negatively with HTT (rho = -0.390, p = .025).

CONCLUSION

Inaccurate self-reported measurements of PA in patients with CMP are associated with alexithymia and interoception. This finding suggests that behavioral interventions targeting alexithymia and interoception in CMP patients could lead to improved self-monitoring.

Exploring the Multidimensional Links Between Trait Mindfulness and Trait Empathy

Empathy and mindfulness are currently major topics of scientific interest. Although it is well-known that mindfulness-typically as an outcome related to meditation-generates empathy at the state level, only a small number of studies have documented the trait (i.e., personality) level association between mindfulness and empathy. Furthermore, the underlying mechanisms (subcomponents and mediator variables) that support this association remain unclear. Thus, here, with a focus on the trait level, we investigated relationships among multiple subcomponents of trait mindfulness and trait empathy (Study 1). Next, we reexamined the aforementioned relationships in an independent sample, with the further aim of investigating relevant mediation factors (Study 2). We found that two attention-related components of trait mindfulness-observing and acting with awareness-reliably and positively related to both affective and cognitive dimensions of trait empathy (i.e., empathic concern and perspective taking). Furthermore, we found that effortful control, reappraisal, and trait alexithymia mediated relationships between the aforementioned attention-related components of trait mindfulness and empathic concern. Taken together, our results suggest that the links between mindfulness and empathy are multidimensional and complex. These findings may ultimately contribute to an understanding of the mechanisms underlying the positive effects of meditation on empathy.

Multidimensional Assessment of Interoceptive Abilities, Emotion Processing and the Role of Early Life Stress in Inflammatory Bowel Diseases

Perception of internal bodily sensations includes three dissociable processes: interoceptive accuracy, interoceptive sensibility, and interoceptive awareness. Interoceptive abilities play a crucial role in emotion processing and impairments of these processes have been reported in several psychiatric disorders. Studies investigating interoceptive abilities and their role in emotional experience in individuals with somatic disorders such as inflammatory bowel diseases (IBD) are sparse. Recent findings suggested an association between adverse childhood experiences (ACE) and the development of gastrointestinal disorders. The aim of the current study was to investigate the associations between the different dimensions of interoception and emotional processing in IBD while taking ACE into account. We recruited IBD patients in clinical remission (n = 35) and 35 healthy control participants (HC) matched for age, education and IQ. Interoception was measured as a three-dimensional construct. Interoceptive accuracy was assessed with the heartbeat tracking task and interoceptive sensibility with a self-report measure (Multidimensional Assessment of Interoceptive Awareness questionnaire). Emotional processing was measured using an experimental task, where participants were asked to rate the subjectively perceived valence and arousal when presented with positive, neutral and negative visual stimuli. IBD patients significantly differed in two interoceptive sensibility domains, Emotional awareness and Not-distracting. Patients reported greater awareness of the connection between bodily sensations and emotional states, while showing a stronger tendency to use distraction from unpleasant sensations compared with HC. Higher emotional awareness was linked to higher perceived intensity and arousal of negative stimuli. The strength of this relation was dependent on the severity of ACE, with severer traumatization being associated with a stronger association between emotional awareness and perceived valence and arousal. Our findings suggest that it is the subjective component of interoception, especially the one assessing interoceptive abilities within the scope of emotional experience, which affects emotional processing in IBD. This is the first study providing evidence that IBD patients did not differ in their perception of visceral signals per se but only in the subjective ability to attribute certain physical sensations to physiological manifestations of emotions. Our findings support the hypothesis that ACE affect the association between interoception and emotional processing.

Suicidality in Adults with Autism Spectrum Disorder: The Role of Depressive Symptomatology, Alexithymia, and Antidepressants

People with autism spectrum disorder (ASD) have an increased risk of suicidality. However, the risk factors remain under-investigated. This study explored factors that increase suicidality risk in ASD. Through an online survey, 150 adults with ASD were compared to 189 control adults. Autistic traits, depressive symptomatology, alexithymia, and antidepressant intake were assessed on their contribution predicting suicidality. Among people with ASD, 63% scored above the cutoff for high suicidality risk. Increased autistic traits, depressive symptomatology, and antidepressant intake significantly predicted suicidality. Furthermore, among those with high levels of autistic traits, the risk of suicidality was increased if they also had high levels of alexithymia. These results highlight the importance of considering depression, antidepressants, and alexithymia to prevent suicidality in ASD.

Using bodily postures to reduce anxiety and improve interoception: A comparison between powerful and neutral poses

BACKGROUND

Previous research has shown that anxiety syndromes are highly prevalent among university students. Effective treatments are needed to reduce the burden of anxiety in this population. Powerful postures have been found to impact affective states, as well as interoception (i.e. the ability to perceive inner bodily signals). However, no previous study has compared the effects of powerful- and neutral postures in regards to anxiety and interoceptive ability.

METHODS

The first part of the study measured the single-session effect of adopting powerful- vs. neutral postures on students' (n = 57) interoceptive ability and state anxiety. The second part of the study measured the effect of adopting powerful or neutral postures twice daily for two weeks, on individuals' interoceptive ability and trait anxiety.

RESULTS

State anxiety decreased in both conditions whereas interoceptive accuracy only increased in the power posing condition after a single session. Interoceptive accuracy increased in both groups after two weeks of training.

LIMITATIONS

The study included no comparison to a condition where individuals adopted their natural (i.e. usual) bodily posture.

CONCLUSIONS

Embodiment interventions that include elements of adopting an open or expansive bodily posture whilst maintaining a self-focus, can help to reduce state anxiety and improve interoceptive accuracy in student populations. Power posing does not seem to be superior to holding a neutral posture to improve interoceptive accuracy or anxiety. One reason therefore could be that both conditions include the manipulation of self-focus and a postural change that diverges from individuals' normal posture.

Using bodily postures in the treatment of anorexia nervosa: Effects of power posing on interoception and affective states

OBJECTIVE

Power posing involves the adoption of an expansive bodily posture. This study examined whether power posing could benefit individuals with anorexia nervosa (AN) and women with normal weight in regards to interoceptive ability and affective states.

METHOD

Participants included 50 inpatients and outpatients with AN as well as 51 normal-weight women. Interoceptive accuracy (IAcc), measured by the heartbeat tracking task and interoceptive sensibility (IS), measured by confidence ratings, were assessed at baseline, after a single power posing session and after 1 week of daily training. Also, the short-term effects of power posing on subjective feelings of dominance, pleasantness, and arousal were investigated.

RESULTS

Both groups increased in their IAcc after one power posing session. Also, there was a significant main effect of time on feelings of dominance and pleasantness in the short-term. Women with AN displayed lower levels of IS, dominance, and pleasantness as well as higher levels of arousal than women without AN.

DISCUSSION

These findings suggest that power posing has the potential to increase IAcc, subjective feelings of power and pleasant affect in the short-term. Further research should investigate which mechanisms foster the effectiveness of this intervention to tailor it to the needs of women with AN.

No preference for direct versus averted gaze in autistic adults: a reinforced preferential looking paradigm

Background

With the overarching objective to gain better insights into social attention in autistic adults, the present study addresses three outstanding issues about face processing in autism. First, do autistic adults display a preference for mouths over eyes; second, do they avoid direct gaze; third, is atypical visual exploration of faces in autism mediated by gender, social anxiety or alexithymia?

Methods

We used a novel reinforced preferential looking paradigm with a group of autistic adults (n = 43, 23 women) pairwise matched on age with neurotypical participants (n = 43, 21 women). Participants watched 28 different pairs of 5 s video recordings of a speaking person: the two videos, simultaneously displayed on the screen, were identical except that gaze was directed at the camera in one video and averted in the other. After a 680 ms transition phase, a short reinforcement animation appeared on the side that had displayed the direct gaze.

Results

None of the groups showed a preference for mouths over eyes. However, neurotypical participants fixated significantly more the stimuli with direct gaze, while no such preference emerged in autistic participants. As the experiment progressed, neurotypical participants also increasingly anticipated the appearance of the reinforcement, based on the location of the stimulus with the direct gaze, while no such anticipation emerged in autistic participants.

Limitations

Our autistic participants scored higher on the social anxiety and alexithymia questionnaires than neurotypicals. Future studies should match neurotypical and autistic participants on social anxiety and alexithymia and complement questionnaires with physiological measures of anxiety.

Conclusions

The absence of preference for direct versus averted gaze in the autistic group is probably due to difficulties in distinguishing eye gaze direction, potentially linked to a reduced spontaneous exploration or avoidance of the eye region. Social attention and preference for direct versus averted gaze correlated with alexithymia and social anxiety scores, but not gender.

Alexithymic and autistic traits: Relevance for comorbid depression and social phobia in adults with and without autism spectrum disorder

LAY ABSTRACT

Adults with autism often develop mental health problems such as depression and social phobia. The reasons for this are still unclear. Many studies found that alexithymia plays an important role in mental health problems like depression. People with alexithymia have difficulties identifying and describing their emotions. Almost every second person with autism has alexithymia. Therefore, we explored in this study whether alexithymia is linked to worse mental health in autistic people. We looked at two common diagnoses, depression and social phobia. We found that alexithymia increased symptoms of depression, while autistic traits increased symptoms of social phobia. Our results suggest that alexithymia and autistic traits can increase the risk of mental health problems. An early assessment could help prevent mental health problems and improve quality of life.

Anxiety in autistic individuals who speak few or no words: A qualitative study of parental experience and anxiety management

Anxiety is a common co-occurring condition in autism and impacts quality of life of autistic individuals and their families; autistic individuals who speak few or no words represent an under-researched group. This qualitative study aimed to understand more about parental recognition and management of anxiety in autistic individuals who speak few or no words. Semi-structured interviews were conducted with parents/carers of 17 autistic individuals (m_age = 14.29) recruited from an existing participant database and social media adverts. Using thematic analysis, 15 themes were placed under three a-priori grand themes: parental recognition of anxiety; parental management of anxiety; and anxiety impact on the autistic individual and their family. Due to reduced verbal language use and overlap with other behaviours, parents described difficulties recognising anxiety in their child. However, they also described use of a number of management strategies, including some which overlap with components of evidence-based interventions for emotional and behavioural problems in autistic individuals (e.g. exposure/sensory calming). Despite this, parents reported that anxiety continues to have significant impact on quality of life. The findings of this study can help to inform the development of targeted intervention and assessment measures for anxiety in autistic individuals who speak few or no words.

Shitsu-taikan-sho (alexisomia): a historical review and its clinical importance

“Shitsu-taikan-sho” is a clinical concept that refers to characteristics of having difficulty in the awareness and expression of somatic feelings or sensations. This concept was first proposed in 1979 by Dr. Yujiro Ikemi, the founder of psychosomatic medicine in Japan, as a characteristic observed in patients with psychosomatic diseases, i.e. physical diseases in which psychosocial factors are closely involved in their onset and progress. Soon after Dr. Ikemi introduced to Japan the concept of alexithymia, coined by P. E. Sifneos in 1973, he noticed that patients with psychosomatic diseases have difficulty in describing not only their emotions, but also somatic feelings and sensations. Dr. Ikemi proposed naming the concept of the trait of lacking somatic awareness “shitsu-taikan-sho” in Japanese (“alexisomia” in English), meaning “shitsu” a lack, “taikan” bodily feelings/sensations, and “sho” condition/symptoms. Dr. Ikemi observed characteristics of both alexithymia and alexisomia in patients with psychosomatic diseases, but considered alexisomia to have a more fundamental pathophysiological role in the understanding of psychosomatic diseases. He also emphasized the importance of treating alexisomia when treating psychosomatic diseases.

Recently, alexisomia has again come into focus for various reasons. One is the availability of the Shitsu-taikan-sho Scale (STSS), a self-rating questionnaire to evaluate alexisomic tendency. Another is recent advances in basic research on interoception. The former will facilitate clinical studies on alexisomia, and the latter will enable a deeper understanding of alexisomia.

This article is an overview of the historical development of the concept of alexisomia which was conceptualized by Dr. Ikemi, introduces the STSS, and discusses the current understanding and clinical importance of alexisomia in psychosomatic medicine.

The Anticipation and Perception of Affective Touch in Women with and Recovered from Anorexia Nervosa

Disruptions in reward processing and anhedonia have long been observed in Anorexia Nervosa (AN). Interoceptive deficits have also been observed in AN, including reduced tactile pleasure. However, the extent to which this tactile anhedonia is specifically liked to an impairment in a specialised, interoceptive C-tactile system originating at the periphery, or a more top-down mechanism in the processing of tactile pleasantness remains debated. Here, we investigated differences between patients with and recovered from AN (RAN) and healthy controls (HC) in the perception of pleasantness of touch delivered in a CT-optimal versus a CT-non-optimal manner, and in their top-down, anticipatory beliefs about the perceived pleasantness of touch. To this end, we measured the anticipated pleasantness of various materials touching the skin and the perceived pleasantness of light, dynamic touch applied to the forearm of 27 women with AN, 24 women who have recovered and 30 HCs using C Tactile (CT) afferents-optimal (slow) and non-optimal (fast) velocities. Our results showed that both clinical groups anticipated tactile experiences and rated delivered tactile stimuli as less pleasant than HCs, but the latter difference was not related to the CT optimality of the stimulation. Instead, differences in the perception of CT-optimal touch were predicted by differences in top-down beliefs, alexithymia and interoceptive sensibility. Thus, tactile anhedonia in AN might persist as a trait even after otherwise successful recovery of AN and it is not linked to a bottom-up interoceptive deficit in the CT system, but rather to a learned, defective top-down anticipation of tactile pleasantness.

Alexithymia may explain the relationship between autistic traits and eating disorder psychopathology

BACKGROUND

Autistic people are disproportionately vulnerable to anorexia nervosa and other eating disorders (ED), and within the general population, autistic traits correlate with ED psychopathology. A putative mechanism which may underpin this heightened risk is alexithymia, a difficulty identifying and describing emotional states which is observed in both autism and ED. In two experiments with independent non-clinical samples, we explored whether alexithymia might mediate the heightened risk of eating psychopathology in individuals high in autistic traits.

METHODS

Our first experiment used the PROCESS macro for SPSS to examine relationships between alexithymia (measured by the Toronto Alexithymia Scale (TAS-20)), autistic traits (autism quotient (AQ)), and eating psychopathology (Eating Attitudes Test (EAT-26)) in 121 participants. Our second experiment (n = 300) replicated and furthered this analysis by examining moderating effects of sex and controlling for anxiety and depression as covariates. We also included an additional performance-based measure of alexithymia, the Levels of Emotional Awareness Scale (LEAS).

RESULTS

Study 1 suggested that TAS-20 scores mediated the relationship between heightened autistic traits and eating psychopathology. Replication and further scrutiny of this finding, in study 2, revealed that this mediation effect was partial and specific to the female participants in this sample. The mediation effect appeared to be carried by the difficulty identifying feelings subscale of the TAS-20, even when depression and anxiety were controlled for. LEAS scores, however, were not significantly related to autistic traits or eating psychopathology.

LIMITATIONS

Cross-sectional data prevents any conclusions around the direction and causality of relationships between alexithymia, autistic traits, and eating psychopathology (alongside depression and anxiety), necessitating longitudinal research. Our non-clinical sample was predominantly Caucasian undergraduate students, so it remains to be seen if these results would extrapolate to clinical and/or autistic samples. Divergence between the TAS-20 and LEAS raises crucial questions regarding the construct validity of these measures.

CONCLUSIONS

Our findings with respect to autistic traits suggest that alexithymia could partially explain the prevalence of ED in autistic people and may as such be an important consideration in the pathogenesis and treatment of ED in autistic and non-autistic people alike. Further research with clinical samples is critical to explore these ideas. Differences between men and women, furthermore, emphasize the importance of looking for sex-specific as well as generic risk factors in autistic and non-autistic men and women.

Vagus Nerve Stimulation as a Gateway to Interoception

The last two decades have seen a growing interest in the study of interoception. Interoception can be understood as a hierarchical phenomenon, referring to the body-to-brain communication of internal signals, their sensing, encoding, and representation in the brain, influence on other cognitive and affective processes, and their conscious perception. Interoceptive signals have been notoriously challenging to manipulate in experimental settings. Here, we propose that this can be achieved through electrical stimulation of the vagus nerve (either in an invasive or non-invasive fashion). The vagus nerve is the main pathway for conveying information about the internal condition of the body to the brain. Despite its intrinsic involvement in interoception, surprisingly little research in the field has used Vagus Nerve Stimulation to explicitly modulate bodily signals. Here, we review a range of cognitive, affective and clinical research using Vagus Nerve Stimulation, showing that it can be applied to the study of interoception at each level of its hierarchy. This could have considerable implications for our understanding of the interoceptive dimension of cognition and affect in both health and disease, and lead to development of new therapeutic tools.

Alexithymia Profile in Relation to Negative Affect in Parents of Autistic and Typically Developing Young Children

In our study, we explored the construct of alexithymia in parents of children with and without ASD using a multi-method approach based on self-rated and external rater assessment. We also assessed the level of self-report measures of negative affect states such as trait anxiety and depression, and investigated the correlation between the alexithymia construct, trait anxiety, and depression within the broader autism phenotype (BAP). A total sample of 100 parents (25 mothers and 25 fathers in each group) were administered the TAS-20 and the TSIA to measure self-reported and observer-rated alexithymia traits, as well as self-report measures of anxiety and depression. Study results showed that the TSIA but not the TAS-20 was able to detect significant group differences in alexithymia traits among parents of children with and without ASD, with parents of ASD children displaying significantly higher levels of alexithymia. Furthermore, differently from the TAS-20, no significant correlations between the TSIA and measures of anxiety and depression were detected. Taken together, our results suggest the importance of using multi-method approaches to control for potential measurement bias and to detect psychological constructs such as alexithymia in subclinical samples such as parents of children with ASD.

Facial emotion recognition in autistic adult females correlates with alexithymia, not autism

Research on predominantly male autistic samples has indicated that impairments in facial emotion recognition typically associated with autism spectrum conditions are instead due to co-occurring alexithymia. However, whether this could be demonstrated using more realistic facial emotion recognition stimuli and applied to autistic females was unclear. In all, 83 females diagnosed with autism spectrum condition completed online self-report measures of autism spectrum condition severity and alexithymia, and afacial emotion recognition deficit that assessed their ability to identify multimodal displays of complex emotions. Higher levels of alexithymia, but not autism spectrum condition severity, were associated with less accurate facial emotion recognition. Difficulty identifying one’s own feelings and externally oriented thinking were the components of alexithymia that were specifically related to facial emotion recognition accuracy. However, alexithymia (and autism spectrum condition severity) was not associated with speed of emotion processing. The findings are primarily discussed with the theoretical view that perceiving and experiencing emotions share the same neural networks, thus being able to recognise one’s own emotions may facilitate the ability to recognise others’. This study is in line with previous similar research on autistic males and suggests impairments in facial emotion recognition in autistic females should be attributed to co-occurring alexithymia.