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

Sensorimotor regulation of facial expression - An untouched frontier

Facial expression is a critical form of nonverbal social communication which promotes emotional exchange and affiliation among humans. Facial expressions are generated via precise contraction of the facial muscles, guided by sensory feedback. While the neural pathways underlying facial motor control are well characterized in humans and primates, it remains unknown how tactile and proprioceptive information reaches these pathways to guide facial muscle contraction. Thus, despite the importance of facial expressions for social functioning, little is known about how they are generated as a unique sensorimotor behavior. In this review, we highlight current knowledge about sensory feedback from the face and how it is distinct from other body regions. We describe connectivity between the facial sensory and motor brain systems, and call attention to the other brain systems which influence facial expression behavior, including vision, gustation, emotion, and interoception. Finally, we petition for more research on the sensory basis of facial expressions, asserting that incomplete understanding of sensorimotor mechanisms is a barrier to addressing atypical facial expressivity in clinical populations.

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.

The Physiological and Clinical-Behavioral Effects of Heart Rate Variability Biofeedback in Adolescents with Autism: A Pilot Randomized Controlled Trial

Adolescents with autism present lower levels of cardiac vagal modulation. It was hypothesized that Heart Rate Variability Biofeedback (HRVB) increases cardiac vagal modulation in adolescents with autism, resulting in positive effects on physiological and psychosocial parameters. It was also hypothesized that home-based HRVB training is feasible. In a single-blind, randomized sham-controlled pilot trial, adolescents with autism performed supervised HRVB (n = 24) or sham training (n = 20). Subsequently, half of the adolescents received HRVB training at home, whereas the other subset did not practice. Physiological, cortisol and behavioral data were collected during stress-provoking assessments before and after each training period. Supervised HRVB resulted in a late increase in cardiac vagal modulation in adolescents with autism. Heart rate increased and cortisol decreased significantly immediately after supervised HRVB, but none of these effects remained after follow-up. Following supervised HRVB, no significant change in psychosocial functioning was found. Home-based HRVB was feasible, adolescents reported lower symptoms of stress, but a significant decrease in compliance rate was found. HRVB is feasible and effective in adolescents with autism given the late-emerging increases in cardiac vagal modulation and decrease in stress symptoms. Replicating this study with a larger sample and further exploration of the working mechanisms of HRVB are recommended. ClinicalTrials.gov , NCT04628715.

'It seems like a luxury to be able to offer that': Factors influencing the implementation of annual health checks for autistic people in England

LAY ABSTRACT

Autistic people are more likely to have mental and physical health problems than non-autistic people. Annual health checks could reduce these problems by finding and treating them early. Annual health checks are yearly medical appointments where a primary healthcare provider (such as a doctor or nurse) can check things like a patient's weight and heart rate and ask if they have any worries about their health. In this study, we wanted to understand what might encourage primary healthcare providers to use annual health checks with their autistic patients. First, we spoke to 10 autistic people and 11 primary healthcare providers. Using the findings from these conversations, we created an online survey for primary healthcare providers in England. We used the findings from the interviews and survey to help us understand what would encourage primary healthcare providers to offer annual health checks for autistic people. Our participants said that a lack of time and staff would make it hard to provide health checks. To help, they said other members of staff (such as nurses and healthcare assistants) could do the health checks, rather than doctors. They also said parts of the process could be made automatic to save time (e.g. sending automatic reminders). Knowledge about autism was important too (e.g. knowing about the common conditions autistic people have, and how to best support autistic patients). Participants said training on these topics, produced and delivered with autistic people, could encourage them to use annual health checks with their autistic patients.

Mental health challenges faced by autistic people

Mental health challenges impede the well-being of autistic people. This Review outlines contributing neurodevelopmental and physical health conditions, rates and developmental trajectories of mental health challenges experienced by autistic people, as well as unique clinical presentations. A framework is proposed to consider four contributing themes to aid personalized formulation: social-contextual determinants, adverse life experiences, autistic cognitive features, and shared genetic and early environmental predispositions. Current evidence-based and clinical-knowledge-informed intervention guidance and ongoing development of support are highlighted for specific mental health areas. Tailored mental health support for autistic people should be neurodivergence-informed, which is fundamentally humanistic and compatible with the prevailing bio-psycho-social frameworks. The personalized formulation should be holistic, considering physical health and transdiagnostic neurodevelopmental factors, intellectual and communication abilities, and contextual-experiential determinants and their interplay with autistic cognition and biology, alongside resilience. Supporting family well-being is integral. Mutual empathic understanding is fundamental to creating societies in which people across neurotypes are all empowered to thrive.

Forwarding the Science of Sensory Features in Autism and Related Conditions

This editorial accompanies the JADD Special Issue on Sensory Features in Autism and Related Conditions: Developmental Approaches, Mechanisms and Targeted Interventions. The editorial is a commentary on the state of the science in sensory features in autism and related conditions and provides a synopsis of the information contained in the special issue including provocative thoughts about moving the field forward in this area.

Acute physical-activity related increases in interoceptive ability are not enhanced with simultaneous interoceptive attention

Interoception, the sense of the internal body, is proposed to support self-regulation, and consequently influence mental health. Researchers have therefore shown interest in improving the ability to accurately monitor internal signals (i.e., interoceptive accuracy, IAcc). Research suggests that cardiac IAcc is modifiable by both manipulations of interoceptive attention (guided attention towards the internal body), and interoceptive exposure (strategically inducing somatic signals e.g., via physical activity). Whilst successful in isolation, it is unclear whether a combined approach (i.e., directing attention towards the internal body when signals are more salient) could elicit greater benefits. In a 2 × 2 within-subject design, 48 healthy adults (M_age = 25.98 ± 4.73 years, 50% female) completed four 20-min conditions varying in both attentional focus (interoceptive vs exteroceptive) and physical activity (active vs rest), with cardiac IAcc measured immediately after. Results revealed a main effect for physical activity (p < 0.001), however, there was no effect for attentional focus (p = 0.397), and no interaction effect (p = 0.797). Differential analyses showed that a higher sporting background increased sensitivity to physical activity-related increases in cardiac IAcc (p = 0.031). Findings indicate that (irrespective of attentional focus) moderate-vigorous physical activity-based interventions have the potential to increase cardiac IAcc, with certain individuals potentially benefiting more.