Reducing auditory hypersensitivities in autistic spectrum disorder: preliminary findings evaluating the listening project protocol

The vagal paradox: A polyvagal solution

Although there is a consistent literature documenting that vagal cardioinhibitory pathways support homeostatic functions, another less frequently cited literature implicates vagal cardioinhibitory pathways in compromises to survival in humans and other mammals. The latter is usually associated with threat reactions, chronic stress, and potentially lethal clinical conditions such as hypoxia. Solving this 'vagal paradox' in studies conducted in the neonatal intensive care unit served as the motivator for the Polyvagal Theory (PVT). The paradox is resolved when the different functions of vagal cardioinhibitory fibers originating in two anatomically distinguishable brainstem areas are recognized. One pathway originates in a dorsal area known as the dorsal motor nucleus of the vagus and the other in a ventral area of the brainstem known as nucleus ambiguus. Unlike mammals, in all ancestral vertebrates from which mammals evolved, cardioinhibitory vagal fibers primarily originate in the dorsal motor nucleus of the vagus. Thus, in mammals the vagus nerve is 'poly' vagal because it contains two distinct efferent pathways. Developmental and evolutionary biology identify a ventral migration of vagal cardioinhibitory fibers that culminate in an integrated circuit that has been labeled the ventral vagal complex. This complex consists of the interneuronal communication of the ventral vagus with the source nuclei involved in regulating the striated muscles of the head and face via special visceral efferent pathways. This integrated system enables the coordination of vagal regulation of the heart with sucking, swallowing, breathing, and vocalizing and forms the basis of a social engagement system that allows sociality to be a potent neuromodulator resulting in calm states that promote homeostatic function. These biobehavioral features, dependent on the maturation of the ventral vagal complex, can be compromised in preterm infants. Developmental biology informs us that in the immature mammal (e.g., fetus, preterm infant) the ventral vagus is not fully functional and myelinization is not complete; this neuroanatomical profile may potentiate the impact of vagal cardioinhibitory pathways originating in the dorsal motor nucleus of the vagus. This vulnerability is confirmed clinically in the life-threatening reactions of apnea and bradycardia in human preterm newborns, which are hypothetically mediated through chronotropic dorsal vagal pathways. Neuroanatomical research documents that the distribution of cardioinhibitory neurons representing these two distinct vagal source nuclei varies among mammals and changes during early development. By explaining the solution of the 'vagal paradox' in the preterm human, the paper highlights the functional cardioinhibitory functions of the two vagal source nuclei and provides the scientific foundation for the testing of hypotheses generated by PVT.

Clinical stance on response initiation in autistic adults: co-creating an integrative approach based on theory and lived experiences to act from language, via motor movement to wellbeing

Getting 'stuck', literally and figuratively, is a common experience for autistic people. Literally 'stuck' means exhibiting limited response initiation due to immobility with tense muscles and inability to move. Figuratively 'stuck' means loneliness, passivity or captivity in activities that do not offer long-term satisfaction. To further conceptualize this complex phenomenon of limited response initiation in autistic individuals, we performed qualitative interviews and focus groups with autistic people and their family members, followed by brainstorm sessions and a Delphi study with input from a larger panel of experts from multiple backgrounds. We aimed to co-create the outline of an integrative approach to support autistic people in moving away from this 'stuck state' to more flexible, limber 'supple states' in order to live freer, more meaningful, satisfying and peaceful lives. Over time, in interaction with all participants, our shared insight grew. Based on this, we here stipulate a conceptual framework, in which the described 'stuck state' at the micro-level of the muscles/behavior of one individual, probably is caused by feeling/being 'stuck' or 'cramped' at several overarching (i.e., meso and macro) levels. For instance, stuck in relationships with unhealthy dynamics, stuck at home creating short-term calm, trance-like states (e.g., gaming), stuck at an educational level that might fit the individuals' current social-emotional state rather than their potential cognitive level, stuck in a job that pays the bills but does not feel meaningful, nor contributes to a satisfying life with opportunities for personal development. Stuck in a mental/public health care system where ever ongoing changes in policies hinder sustained support to suit care-needs. Stuck in a regulated societal system making it likely to repeatedly get stuck. Is this phenomenon specific to autism? Formally we have only conducted interviews with this population, but in another smaller, related project we also spoke to people from the general population with careers that are considered successful in the general society. These people actually voiced similar experiences. Therefore, we hypothesize that this numbing state of being or feeling 'stuck' may be a prevalent phenomenon that needs to be addressed. In this article, we discuss several types of interventive approaches (i.e., language-based talking therapies, affective experiential expressive therapies, physical therapies and systemic therapies), prevention as well as intervention programs, directed at different primary stakeholders, that can complement and enrich each other in an integrative policy, that leads to tailor-made, personalized trajectories of interdisciplinary support to enable people to live satisfying, meaningful, dignified and peaceful lives.

Initial Outcomes of the Safe and Sound Protocol on Patients with Adult Autism Spectrum Disorder: Exploratory Pilot Study

Sensory impairments are common features of autism spectrum disorder (ASD) and are associated with its social impairments. However, there is no established treatment for these impairments in adults with ASD. The Safe & Sound Protocol (SSP) is a listening program designed to improve social communication skills by reducing auditory hypersensitivity. We investigated the effectiveness of the SSP for adults with ASD. We administered the SSP to six participants with ASD aged 21-44 years old, and the effects were assessed using the Social Responsiveness Scale, Second Edition (SRS-2). Secondary outcomes were assessed using the Center for Epidemiological Studies Depression Scale (CES-D), State-Trait Anxiety Inventory (STAI), WHO Quality of Life 26 (WHOQOL-BREF), and Adolescent/Adult Sensory Profile (A/ASP). In this study, only the Social Awareness scale of the SRS-2 Family-Report showed a significant improvement after the intervention. In addition, it was significantly correlated with physical health of WHOQOL-BREF (r = -0.577, p = 0.012), state and trait anxiety of STAI (r = 0.576, p = 0.012; r = 0.708, p = 0.00009, respectively), and CES-D (r = 0.465, p = 0.05). In conclusion, the SSP has a partial effect on social impairments in adults with ASD, specifically on the Social Awareness subscale of the SRS-2.

Polyvagal Theory: A Science of Safety

Contemporary strategies for health and wellbeing fail our biological needs by not acknowledging that feelings of safety emerge from internal physiological states regulated by the autonomic nervous system. The study of feelings of safety has been an elusive construct that has historically been dependent upon subjectivity. Acknowledging that feelings of safety have a measurable underlying neurophysiological substrate would shift investigations of feelings of safety from a subjective to an objective science. Polyvagal Theory provides an innovative scientific perspective to study feelings of safety that incorporates an understanding of neuroanatomy and neurophysiology. This perspective identifies neural circuits that downregulate neural regulation of threat reactions and functionally neutralize defensive strategies via neural circuits communicating cues of safety that enable feelings of safety to support interpersonal accessibility and homeostatic functions. Basically, when humans feel safe, their nervous systems support the homeostatic functions of health, growth, and restoration, while they simultaneously become accessible to others without feeling or expressing threat and vulnerability. Feelings of safety reflect a core fundamental process that has enabled humans to survive through the opportunistic features of trusting social engagements that have co-regulatory capacities to mitigate metabolically costly defense reactions. Through the study of neural development and phylogeny, we can extract foundational principles and their underlying mechanisms through which the autonomic nervous system leads to feelings of safety and opportunities to co-regulate. Several principles highlight the validity of a science of safety that when implemented in societal institutions, ranging from healthcare to education, would enhance health, sociality, and lead to greater productivity, creativity, and a sense of wellbeing. By respecting our need to feel safe as a biological imperative linked to survival, we respect our phylogenetic heritage and elevate sociality as a neuromodulator that functionally provides the scientific validation for a societal focus on promoting opportunities to experience feelings of safety and co-regulation.

Intersubjectivity: Conceptual Considerations in Meaning-Making With a Clinical Illustration

This manuscript explores intersubjectivity through a conceptual construct for meaning-making that emphasizes three major interrelated elements-meaning making in interaction, making meaning with the body as well as the mind, and meaning making within an open dynamic system. These three elements are present in the literature on intersubjectivity with a wide range of terms used to describe various theoretical formulations. One objective of this manuscript is to illustrate how such a construct can be useful to understand the meaning-making observed in psychoanalysis, such as in the treatment of a young child on the autistic spectrum. The challenges in establishing an intersubjective state with a child on the autistic spectrum serve to highlight important features of intersubjectivity. As an important background to this clinical illustration, we illustrate the construct with the scientific paradigm of the well-known face-to-face still-face.

Prevalence of Decreased Sound Tolerance (Hyperacusis) in Individuals With Autism Spectrum Disorder: A Meta-Analysis

OBJECTIVES

Hyperacusis, defined as decreased tolerance to sound at levels that would not trouble most individuals, is frequently observed in individuals with autism spectrum disorder (ASD). Despite the functional impairment attributable to hyperacusis, little is known about its prevalence or natural history in the ASD population. The objective of this study was to conduct a systematic review and meta-analysis estimating the current and lifetime prevalence of hyperacusis in children, adolescents, and adults with ASD. By precisely estimating the burden of hyperacusis in the ASD population, the present study aims to enhance recognition of this particular symptom of ASD and highlight the need for additional research into the causes, prevention, and treatment of hyperacusis in persons on the spectrum.

DESIGN

We searched PubMed and ProQuest to identify peer-reviewed articles published in English after January 1993. We additionally performed targeted searches of Google Scholar and the gray literature, including studies published through May 2020. Eligible studies included at least 20 individuals with diagnosed ASD of any age and reported data from which the proportion of ASD individuals with current and/or lifetime hyperacusis could be derived. To account for multiple prevalence estimates derived from the same samples, we utilized three-level Bayesian random-effects meta-analyses to estimate the current and lifetime prevalence of hyperacusis. Bayesian meta-regression was used to assess potential moderators of current hyperacusis prevalence. To reduce heterogeneity due to varying definitions of hyperacusis, we performed a sensitivity analysis on the subset of studies that ascertained hyperacusis status using the Autism Diagnostic Interview-Revised (ADI-R), a structured parent interview.

RESULTS

A total of 7783 nonduplicate articles were screened, of which 67 were included in the review and synthesis. Hyperacusis status was ascertained in multiple ways across studies, with 60 articles employing interviews or questionnaires and seven using behavioral observations or objective measures. The mean (range) age of samples in the included studies was 7.88 years (1.00 to 34.89 years). The meta-analysis of interview/questionnaire measures (k(3) = 103, nASD = 13,093) estimated the current and lifetime prevalence of hyperacusis in ASD to be 41.42% (95% CrI, 37.23 to 45.84%) and 60.58% (50.37 to 69.76%), respectively. A sensitivity analysis restricted to prevalence estimates derived from the ADI-R (k(3) = 25, nASD = 5028) produced similar values. The estimate of current hyperacusis prevalence using objective/observational measures (k(3) = 8, nASD = 488) was 27.30% (14.92 to 46.31%). Heterogeneity in the full sample of interview/questionnaire measures was substantial but not significantly explained by any tested moderator. However, prevalence increased sharply with increasing age in studies using the ADI-R (BF10 = 93.10, R2Het = 0.692).

CONCLUSIONS

In this meta-analysis, we found a high prevalence of current and lifetime hyperacusis in individuals with ASD, with a majority of individuals on the autism spectrum experiencing hyperacusis at some point in their lives. The high prevalence of hyperacusis in individuals with ASD across the lifespan highlights the need for further research on sound tolerance in this population and the development of services and/or interventions to reduce the burden of this common symptom.

Polyvagal Theory: A biobehavioral journey to sociality

A polyvagal perspective clarifies the neurobiological and biobehavioral shifts that occurred during evolutionary transition from asocial reptiles to social mammals. This transition enabled mammals, unlike their reptilian ancestors, to derive a biological benefit from social interactions. This innovation enabled social behavior to function as a neuromodulator that could efficiently regulate and optimize autonomic function to support homeostatic processes. This journey is highlighted by the phylogenetic transition during which the autonomic nervous system was repurposed to suppress defensive strategies to support and express sociality. The product of this transition was an autonomic nervous system with capacities to self-calm, to spontaneous socially engage others, and to mitigate threat reactions in ourselves and others through social cues. Thus, social behavior became embedded with specific neurobiological processes that had capabilities to support homeostatic functions leading to optimized health, growth, and restoration. Polyvagal Theory emphasizes sociality as the core process in mitigating threat reactions and supporting mental and physical health.

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Sociality in mammals co-evolved with a repurposed autonomic nervous system.

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Evolution repurposed the mammalian ventral vagal complex in the brainstem to support sociality.

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Social behavior functions as a neuromodulator optimizing behavioral, autonomic, and emotional state regulation.

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Neuroception reflexively detects risk or safety without awareness and shifts autonomic state to support adaptive behaviors.

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Unlike their reptilian ancestors, mammals have a neuroception to safety that fosters sociality by calming autonomic state.

Effectiveness of Noise-Attenuating Headphones on Physiological Responses for Children With Autism Spectrum Disorders

Objective: The purpose of this study was to evaluate the proof of concept of an intervention to decrease sympathetic activation as measured by skin conductivity (electrodermal activity, EDA) in children with an autism spectrum disorder (ASD) and auditory hypersensitivity (hyperacusis). In addition, researchers examined if the intervention provided protection against the negative effects of decibel level of environmental noises on electrodermal measures between interventions. The feasibility of implementation and outcome measures within natural environments were evaluated.

Method: A single-subject multi-treatment design was used with six children, aged 8–16 years, with a form of Autism (i.e., Autism, PDD-NOS). Participants used in-ear (IE) and over-ear (OE) headphones for two randomly sequenced treatment phases. Each child completed four phases: (1) a week of baseline data collection; (2) a week of an intervention; (3) a week of no intervention; and (4) a week of the other intervention. Empatica E4 wristbands collected EDA data. Data was collected on 16–20 occasions per participant, with five measurements per phase.

Results: Separated tests for paired study phases suggested that regardless of intervention type, noise attenuating headphones led to a significance difference in both skin conductance levels (SCL) and frequency of non-specific conductance responses (NS-SCRs) between the baseline measurement and subsequent phases. Overall, SCL and NS-SCR frequency significantly decreased between baseline and the first intervention phase. A protective effect of the intervention was tested by collapsing intervention results into three phases. Slope correlation suggested constant SCL and NS-SCR frequency after initial use of the headphones regardless of the increase in environmental noises. A subsequent analysis of the quality of EDA data identified that later phases of data collection were associated with better data quality.

Conclusion: Many children with ASD have hypersensitivities to sound resulting in high levels of sympathetic nervous system reactivity, which is associated with problematic behaviors and distress. The findings of this study suggest that the use of noise attenuating headphones for individuals with ASD and hyperacusis may reduce sympathetic activation. Additionally, results suggest that the use of wearable sensors to collect physiological data in natural environments is feasible with established protocols and training procedures.

Assessing body awareness and autonomic reactivity: Factor structure and psychometric properties of the Body Perception Questionnaire-Short Form (BPQ-SF)

Body awareness and reactivity dysfunction are characteristic of a range of psychiatric disorders. Although the neural pathways communicating between the body and brain that contribute to these experiences involve the autonomic nervous system, few research tools for studying subjective bodily experiences have been informed by these neural circuits. This paper describes the factor structure, reliability, and convergent validity of the Body Awareness and Autonomic Reactivity subscales of the Body Perception Questionnaire-Short Form (BPQ-SF). Exploratory and confirmatory factor analyses were applied to data from three samples collected via the internet in Spain and the US and a college population in the US (combined n = 1320). Body awareness was described by a single factor. Autonomic reactivity reflected unique factors for organs above and below the diaphragm. Subscales showed strong reliability; converged with validation measures; and differed by age, sex, medication use, and self-reported psychiatric disorder. Post hoc analyses were used to create the 12-item Body Awareness Very Short Form. Results are discussed in relation to the distinct functions of supra- and sub-diaphragmatic autonomic pathways as proposed by the Polyvagal Theory and their potential dysfunction in psychiatric disorders.

Interventions Targeting Sensory Challenges in Autism Spectrum Disorder: A Systematic Review

CONTEXT

Sensory challenges are common among children with autism spectrum disorder (ASD).

OBJECTIVE

To evaluate the effectiveness and safety of interventions targeting sensory challenges in ASD.

DATA SOURCES

Databases, including Medline and PsycINFO.

STUDY SELECTION

Two investigators independently screened studies against predetermined criteria.

DATA EXTRACTION

One investigator extracted data with review by a second. Investigators independently assessed risk of bias and strength of evidence (SOE), or confidence in the estimate of effects.

RESULTS

Twenty-four studies, including 20 randomized controlled trials (RCTs), were included. Only 3 studies had low risk of bias. Populations, interventions, and outcomes varied. Limited, short-term studies reported potential positive effects of several approaches in discrete skill domains. Specifically, sensory integration-based approaches improved sensory and motor skills-related measures (low SOE). Environmental enrichment improved nonverbal cognitive skills (low SOE). Studies of auditory integration-based approaches did not improve language (low SOE). Massage improved symptom severity and sensory challenges in studies with likely overlapping participants (low SOE). Music therapy studies evaluated different protocols and outcomes, precluding synthesis (insufficient SOE). Some positive effects were reported for other approaches, but findings were inconsistent (insufficient SOE).

LIMITATIONS

Studies were small and short-term, and few fully categorized populations.

CONCLUSIONS

Some interventions may yield modest short-term (<6 months) improvements in sensory- and ASD symptom severity-related outcomes; the evidence base is small, and the durability of the effects is unclear. Although some therapies may hold promise, substantial needs exist for continuing improvements in methodologic rigor.