By Casey Burgess, Lakehead University
This article was published as part of Reframed: The Journal of Self-Reg Volume 2, Issue 1 (2018)
Burgess, C. (2018) Reframing Autism Spectrum Disorder: ASD through a Neuropsychological Reframe: The Journal of Self-Reg, 2(1),
Autism Spectrum Disorder (ASD) is described in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) according to diagnostic criteria focused on observable, behaviour-based characteristics, including social reciprocity (for example, conversation skills), nonverbal communicative behaviour, relationship development (for example, ability to adjust behaviour to suit social context), stereotyped motor movements, ritualized patterns of behaviour, restricted interests, and hyper- or hypo-reactivity to sensory input. However, it is known in the academic research community through advances in neuroscience that ASD is a neurodevelopmental disorder, and not a disorder of behaviour. A neurodevelopmental or psychophysiological lens encourages a focus on the autonomic states underlying behaviour and communication, rather than on conscious behavioural choice or behaviours themselves, and may therefore facilitate a more scientifically accurate means of conceptualizing ASD. While the DSM-5 diagnostic criteria focus on identifying certain characteristic behaviours, Porges’ Polyvagal Theory, a psychophysiological model of human development, describes differences in the social engagement system that help explain these behaviours. It also points to alternate, and perhaps more successful, approaches to intervention based on neuroscience. Rather than treating the behaviourally based diagnostic characteristics or symptoms of ASD, an intervention focused on the underlying autonomic causes of behaviour allows us to lay developmental foundations that lead children to learn more naturally through engagement with their environments and ultimately follow a more typical developmental trajectory.
Keywords: autism, autism spectrum disorder, ASD, social engagement system, Polyvagal Theory, self-regulation, neurology, neurodevelopmental, psychophysiology, intervention.
Reframing Autism Spectrum Disorder: ASD through a Neuropsychological Lens
Autism Spectrum Disorder (ASD) affects 1 in 68 children and its prevalence continues to increase (Christensen, 2016). The need to support children in more effective and efficient ways is more critical than ever. According to the American Psychiatric Association (2013), ASD is characterized by deficits in social communication and social interaction (social reciprocity, nonverbal communication, and relationship development), as well as by restricted and repetitive patterns of behaviour, interests, or activities (motor movements, speech, inflexibility, intense focus of interests). It is typically diagnosed using tools such as the Childhood Autism Rating Scale (Schopler, Reichler, DeVellis, & Daly, 1980) to guide the measurement of observable behaviours or “symptoms” aligned with the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), a standard manual of diagnoses for North American diagnosticians (American Psychiatric Association, 2013). Public funding for interventions is geared towards behaviourally based support (Government of Ontario, 2017), which has a known evidence base for altering the behavioural symptoms or characteristics of autism and teaching milestone skills across a variety of learning domains.
Clinicians, though, have varied in their theoretical concepts of ASD (Parks, 1983). Founded on science and understanding of neurology, the academic research community knows ASD to be a neurodevelopmental disorder, not one of behaviour. However, our mainstream, publicly funded intervention remains behaviourally based. This paradox in etiology, diagnosis, and mainstream intervention can potentially be reconciled using a more integrated model of the nervous system in understanding ASD and approaching intervention using this lens.
Since Darwin’s early (1872) discussion of the bidirectional neural communication between the brain and the heart (through a nerve he called the pneumogastric nerve, now known as the vagus), research in human development has looked at how the brain and body communicate. Recent research emphasizes the importance of brain–body communication to psychopathology, including epilepsy, depression, and many of the behaviours associated with ASD (Porges, 2011). Porges’ Polyvagal Theory and its described “social engagement system” are based on neurophysiology and provide an alternate and perhaps more plausible account of the functional and developmental challenges faced by individuals with ASD, which leads to a philosophical reframing of how to best support lifelong development, learning, and well-being of individuals with ASD.
The Polyvagal Theory encourages scientists to consider the role of the nervous system in the regulation of biobehavioural processes (Porges, 2007) and thus helps us to better understand ASD. It explains the dysregulation of the organs often seen in ASD (heart rate, gut, and digestion problems), which are regulated by the nervous system. It describes the visceral pain tolerance threshold, connected to the sensory challenges which are part of ASD’s DSM- 5 diagnostic criteria. It provides an explanation for the more complex information processing challenges, such as executive functioning difficulties, that are also known to be key processing challenges in ASD. Lastly, and perhaps most importantly, it accounts for challenges in social engagement that underlie the functioning of the nervous system and the foundational challenges of social communication inherent to ASD diagnosis and later development and learning. Essentially, the diagnostic criteria established in the DSM-5 are specific to behaviours controlled by the Polyvagal Theory’s social engagement system, including eye gaze, facial expression, body postures, joint attention, expressive language, and more (Patriquin, Scarpa, Friedman, & Porges, 2013). Examining ASD from this perspective may lead to interventions focused on the upstream developmental foundations of ASD rather than its downstream behavioural symptoms and skill deficits.
The Polyvagal Theory
The Polyvagal Theory involves the vagus nerve, which is responsible for the bidirectional communication between the state of the body and the nervous system. The theory proposes that there are three aspects of the autonomic nervous system that exert neural control over the heart (Porges, 2011). First, there exists an unmyelinated dorsal motor vagus which regulates the organs below the diaphragm, including the digestive system, and stress- related hormones such as dopamine, serotonin, and cortisol. Second, the sympathetic-adrenal system, which primes us for immediate mobilization without having to consciously think about it when threatened by activating the muscles required for immediate escape or avoidance and inhibiting the sub-diaphragmatic processes, such as digestion, to conserve energy for survival. Lastly, the parasympathetic nervous system’s myelinated vagus, which is more recently evolved in mammals as opposed to other animals, calms us and allows us to engage consciously with the environment around us through social communication to inhibit the fight-or-flight responses and to become involved with our environment in a much more complex way than other animals. This is what is known as the social engagement system (Porges, 2011).
These self-regulatory processes can be examined through vagal tone, measured via respiratory sinus arrhythmia (RSA). RSA is the variation of heart rate with breathing as the body responds to the environment. When the heart rate varies with response, it demonstrates adaptability to stressors and ability of the nervous system to recover from exposure to stressors. Research has shown differences in the RSA of individuals with ASD in response to various stimuli and task demands (Porges, 2011). Children with ASD do not suppress RSA (recover from stressors) as well as their typically developing peers (Hutt, Forrest, & Richer, 1975). There are clear differences in the nervous systems of children with ASD compared with their peers.
Higher amplitude RSA indicates overall functioning (Thayer & Lane, 2009), and the ability to reduce this amplitude is associated with better cognitive function (that is, processing speed, working memory, learning, and receptive language skills) (Beauchaine, 2001). Individuals who show greater RSA suppression when subjected to stress do better in terms of on-task cognitive function, such as executive function (Blair, 2003) and fluid intelligence (Staton, El-Sheikh, & Buckhalt, 2009). The connection between RSA and cognitive function is robust in the research (Patriquin et al., 2013) and demonstrates that ability to suppress RSA (the nervous system’s ability to recover after stress) is adaptive and may impact the cognitive function of individuals with ASD. Higher vagal tone, leading to the ability to suppress RSA, may be a protective factor against some of the challenges of psychopathology (Patriquin et al., 2013). In ASD, RSA has been shown to predict concurrent and future communication skills (Watson, Baranek, Roberts, David, & Perryman, 2010) and is associated with self-regulation, which is critical to social engagement (Porges, 2011). The Polyvagal Theory, RSA, and vagal tone are certainly areas worth expanding on in ASD research. Such research could lead not only to the development of better support for communication and learning skills, but also to improved approaches to health concerns related to digestion and sensory processing that may cause discomfort and become additional stressors on the nervous systems of individuals with ASD, therefore exacerbating their challenges.
Symptoms of ASD Seen through a Neurobiological Lens Digestion
The higher the vagal tone, the better (more resilient) the heart and gut responses to stress, so understanding that individuals with ASD tend to have lower vagal tone explains some of the digestive/gut difficulties that present themselves in many individuals with ASD. Low vagal tone compromises the functioning of the gut, heart, and pancreas – health problems common in ASD (Horvath & Perman, 2002). There are many unsolved questions regarding the relationship of digestive problems to ASD diagnosis, etiology, and treatment, and the Polyvagal Theory provides a framework through which to examine how these digestive difficulties are connected to vagal regulation of the nervous system, which also affects the other aspects of ASD diagnosis (Porges, 2011). Further research into the relationship between vagal regulation and digestive difficulties may provide answers to and direction for some of the inconclusive research on the relationship between digestive disorders and ASD.
The vagus is involved in communicating the state of the body to the brain, allowing us to feel and interpret what the body is feeling through sensory experiences – tactile, visual, auditory, gustatory, olfactory, vestibular, proprioceptive, interoceptive, and neuroceptive (Porges, 2011). Having decreased vagal tone impacts the sensory processing of individuals with ASD. For example, individuals with ASD have shown dampened transitory heart rate responses to a variety of incoming sensory stimuli, including auditory stimuli (Zahn, Rumsey, & Van Kammen, 1987) and socially relevant speech (Palkovitz & Wiesenfeld, 1980). The Polyvagal Theory helps us understand how the sensory component of the DSM-5 diagnostic criteria of ASD connects to other areas of the diagnosis (such as social communication) by understanding ASD as founded in nervous system functioning. The Polyvagal Theory allows us to see that the nervous system processes are disrupted in ASD, and that individuals with ASD have difficulty recruiting the neural circuits responsible for communicating body–brain information through the social engagement system (Porges, 2011). Not being able to regulate this body– brain information results in decreased engagement when the individual processes incoming sensory information as threatening, and it can also lead to fight-or-flight responses that inhibit the natural learning process. This accounts well for some of the developmental challenges that can change someone with ASD’s learning trajectory.
Social Engagement and Behaviours
The Polyvagal Theory examines the brain structures that regulate social and defensive behaviours, known areas of difficulty for individuals with ASD (Porges, 2011). The theory proposes that a person’s neurophysiological state affects their “range of emotional expression, quality of communication, and the ability to regulate bodily and behavioural state” (Porges, 2011, p. 118). Because the theory examines the development of the autonomic nervous system involving “affective experience, emotional expression, facial gestures, vocal communication, and contingent social behaviour” (Porges, 2011, p. 118), it provides an explanation for the communicative, emotional, and social characteristics defining ASD, through the social engagement system.
During embryo development, several cranial nerves develop together through the vagus to form the social engagement system. This system involves a control component in the cortex which regulates the brain stem to control the face and neck muscles responsible for looking, emotional expression, differentiating the human voice, eating, vocalizing, and head-turning for social orientation and social gestures (Porges, 2011). These coordinated muscles determine engagement with the environment and social experience; they allow us to scan for safety cues in
the people and things around us and to remain calm so that our bodies can rest, restore, and recover from stressors and thus maintain the social engagement process. Engagement behaviours such as looking at people, emotional expression, and differentiation of the human voice are connected within the social engagement system. The neural pathways that allow us to raise our eyelids are the same ones that tense the stapedius muscles in the inner ear facilitating the ability to hear the human voice (Borg & Counter, 1989). This neural regulation of the inner ear muscles (shown to be necessary for listening to the human voice) is known to be defective in individuals with ASD (Smith, Miller, & Stewart, 1988; Thomas, Mcmurry, & Pillsbury, 1985). The observed difficulties in ASD may be connected to the same system involved in facial expression as well (Porges, 2011); we can see that individuals with ASD have great difficulty recruiting the neural circuits regulating the social engagement system.
Respiratory sinus arrhythmia (a measure of neural functioning as discussed above) is linked to positive social- cognitive function (Bal et al., 2010; Van Hecke et al., 2009) in children with ASD, and correlates with joint attention, use of social gestures, and receptive language ability (Patriquin et al., 2013). Recent studies have confirmed that RSA correlates with social functioning in children with ASD; children with ASD who have higher baseline RSA show better social skills and fewer behaviour challenges (Van Hecke et al., 2009), and they are better at recognizing emotions (Bal et al., 2010). However, children with ASD have been shown to have lower RSA overall than their typically developing peers (Guy, Souders, Bradstreet, DeLussey, & Herrington, 2014), indicating a lesser ability to regulate their state via the nervous system, which is so critical to later stages of development and learning.
ASD seen through this lens is not a lack of social skill development, but a withdrawal from social contact as an adaptive mechanism (responding to perceived or real environmental threats), which is behaviourally expressed as limited facial expressions, head gestures, ability to discriminate the human voice, and prosody, all elements or diagnostic characteristics of ASD. In other words, our ability to use social cues from the environment helps us calm our bodies and inhibit fight-or-flight responses to learn, but this is not always possible for individuals with ASD. Using social cues to signal safety allows us, from birth forward, to develop neural control of the facial and vocal muscles required for social communication and to engage calmly and more readily with our environments without having to expend our energy on protective fight-or- flight mechanisms. Developmentally, because of this deficit in the social engagement system as shown by measures of vagal tone, children with ASD have difficulty learning from their environments because their nervous systems have deficits which keep them in a state of fight-or-flight rather than calm and alert social engagement. Thus, by targeting the social engagement system as an upstream intervention during development, we open the door to a developmental trajectory where children are socially engaged, and thus learn as their typically developing peers do through their own intrinsic curiosity and engagement with their environments, rather than downstream behaviourally based skill development interventions.
Impact of a Neurobiological Understanding of ASD on Intervention
The vagus nerve “directly supports the behaviours needed to engage and disengage with the environment” (Bridges & Porges, 2015), which are a foundational element of any type of ASD understanding and intervention. When we understand ASD to be a disruption of the nervous system and not a conscious control of behaviour, our approaches and interventions become based on supporting self-regulation rather than on controlling behaviour and teaching concrete skills. Further, we change our approaches when we consider that some of the maladaptive behaviours inherent in ASD are most likely the result of coping with heightened stress. Rather than responding with behaviour modification strategies which may focus on how best to avoid or respond to the behaviour, we can take the approach
of reducing stressors as a prerequisite to trying to reduce the unwanted behaviour (which will likely lead to reduction in maladaptive behaviour anyway). A self-regulation approach, where self-regulation is defined as the process of responding to and recovering from stress, prompts us to focus on the child’s ability, as part of their development from infancy on, to self-regulate. The ability to self-regulate is a foundational ability serving as a precursor to social engagement and later learning and behaviour (Greenspan & Shanker, 2004). The brain–body connection inherent in self-regulation contributes to lifelong development and not just present behavioural repertoire.
Because deficits in the social engagement system create challenges in spontaneous social behaviour, social awareness, affect expression, prosody, and language development, improving neural regulation should help address the challenges of ASD (Porges, 2011). Interventions founded on relevant philosophies of neurodevelopment are gaining momentum in the research as families and clinicians seek alternative approaches to publicly funded behaviour therapies. DIRFloortime (Greenspan & Wieder, 2006) is one such model used to support individuals with ASD through developmental, individual, relationship- based interactions centred around play. Beginning with a foundation of self-regulation, the intervention builds to expand on where and how a child feels safe and engaged, gradually helping him/her to remain regulated through increasingly complex interactions. It is evidence- based, and this area of research is continuing to grow (Casenhiser, Binns, McGill, Morderer, & Shanker, 2015; Casenhiser, Shanker, & Stieben, 2013; Solomon, Necheles, Ferch, & Bruckman, 2007). Another developmental and relationship-based intervention for ASD is Relationship Development Intervention (RDI), which is a parent-based, cognitive-developmental approach where caregivers are taught to provide specific daily opportunities for successful functioning in increasingly challenging ways (Gutstein, Burgess, & Montfort, 2007). RDI purports to create developmental, neurocognitive changes, and includes key aspects of self-regulation and co-regulation which allow the child to engage with his/her environment and those around him/her, and thus to learn more effectively on his/her own in the future. RDI shows some preliminary evidence of success (Gutstein et al., 2007), though more research is needed. Beyond these intensive interventions, simply reframing ASD – seeing it from its neurological foundations, and not from its behavioural symptoms – encourages parents, educators, and others who support individuals with ASD to take an approach to learning and intervention which sees self-regulation as the foundation for child development. Working on self-regulation as a critical foundational skill to learning and development leads to better developmental trajectories and more natural learning across learning domains in the future.
By shifting our focus from the downstream behavioural symptoms of ASD to their underlying upstream etiology from a developmental, neuroscientific perspective, we are led in a promising new direction of intervention based on children’s neural development rather than behavioural milestones. Certainly, we can teach skills and behaviours using behavioural theory, but reframing ASD prompts us to consider how to set the stage developmentally and neurologically as a prerequisite for even more effective skill development. When we focus on self-regulation as the foundation of child development, and see that self- regulation precedes social engagement, learning, and later skills, we allow the nervous system to develop in a way that enhances social engagement and natural learning of critical developmental milestone skills. Further, it decreases maladaptive behaviour by creating a safe environment which supports a calm and adaptive nervous system primed for social engagement, creativity, and natural learning. The prevalence of ASD continues to increase, as does the need for classroom support, developmental skill building, and later adult services, despite the implementation of evidence-based behavioural interventions. Perhaps this is a revolution in thinking that is well overdue.
Continue the Learning
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