by Rachel Davis
figures by Xiaomeng Han

The Academy Award-winning performance of Dustin Hoffman as an autistic savant in the movie Rain Man brought the condition of autism spectrum disorder (ASD) sharply into the spotlight. While the movie helped raise awareness and research funding for the condition, it also created a misconception that autism is, at its core, tied together with genius. To this day, our collective perceptions of ASD are often muddled and confused. However, academic research combined with the neurodiversity movement have led to a more holistic understanding of this condition. This heightened understanding has informed interventions that benefit people with autism in their everyday lives. So, what does ASD research teach us about the condition, and how can these research findings be translated into real-world interventions?

Autism spectrum disorder

According to the Centers for Disease Control and Prevention (CDC), ASD is a condition diagnosed mainly by observable behaviors. These include repetitive behaviors, difficulty connecting and communicating with people in a typical way, and delays in developmental milestones, such as speech. Even though the initial diagnosis is based entirely on symptomatology, genetic tests can sometimes reveal an underlying genetic driver. Moreover, genetics, biology, and environment are all capable of contributing to the development of ASD (Figure 1). For example, maternal diet, low birthweight, and duplications or deletions within chromosome 16 have all been implicated in ASD.

Figure 1: Development of autism. Similar to the different factors that contribute to a plant’s growth, different factors also contribute to the development of ASD. These include genetics, biology, and a person’s environment. While only one could be a driving force, in many cases there is not one primary condition driver.

Importantly, ASD presents differently in each individual, complicating the delivery of the support necessary for a person with ASD to live their life to its fullest potential. Current interventions for ASD focus on symptom management, which can improve the abilities of people with ASD to connect, communicate, and function independently in society. Treatments range from tailored education plans to behavioral and pharmacological intervention. But for many people within the autistic community, medical interventions are not enough – their desire to reframe the way society thinks about ASD has given rise to the neurodiversity movement.

The neurodiversity movement

Neurodiversity refers to the span of cognitive and neurological differences within the human population. First used primarily in reference to ASD, the term now encompasses other conditions, including attention-deficit/hyperactivity disorder (ADHD), Tourette syndrome, dyslexia, and obsessive-compulsive disorder (OCD). Neurodiversity represents the multitude of ways in which people’s brains can differ from what is considered typical. These can be divergences in the way people think, behave, and process the world around them. In the context of ASD, neurodiversity often means variability in sensory perception and social and emotional behavior.

Since sociologist Judy Singer coined the term in 1997, neurodiversity has evolved into an entire movement, seeking to alter the perception of neurodivergence from a pathology into an accepted, valued difference in cognition that does not necessarily need to be treated or cured. Instead, neurodiversity calls on society to support and adapt for people with ASD, rather than the other way around (Figure 2).

Figure 2: Neurodiversity movement reshapes how we think about ASD. While ASD has historically been considered a disability – something society felt needed to be treated or cured – the neurodiversity movement has started to shift the focus towards acceptance and support.

Research on ASD

Given the call to adapt society to be ASD-accessible, instead of treating the people with ASD, the question becomes: how can society adapt? Some answers can come from scientific research. For example, research that aims to understand the sensory and behavioral differences that accompany ASD can inform adaptations within spaces to allow people with autism to more comfortably exist. According to a review article, atypical sensory perception stemming from altered networks within the brain is likely at the core of behaviors associated with autism. This atypical sensory perception can cause people with ASD to hyperfocus on some aspects of their sensory experience while being blind to others. The review suggests that some people with ASD “[see] the trees, but not the forest,” meaning they are more attuned to the details of smaller, local stimuli than the average person, but less perceptive of the big picture. As research suggests that sensory perception is central to the autistic experience and atypical sensory perception is linked to higher-order cognitive differences in people with ASD, sensory perception can be used as both a diagnostic test and an intervention target. 

Translation of ASD research to the real world

One application of research into sensory perception with autism comes from an article in which researchers made alterations to a classroom with the goal of reducing sensory overload for students with autism. Specifically, they introduced sound-absorbing walls and halogen lighting. The interventions focused on sound and vision because these are common hypersensitivity triggers for people with autism. The sound-absorbing walls decrease the volume of noise that distracts the students, while the halogen lighting, which is softer and more natural, reduces the stress associated with fluorescent lights, decreasing the students’ repetitive behaviors (Figure 3).

Figure 3: Supporting atypical sensory experiences. Research on ASD has led to an understanding of how sensory experiences shape behavior and has informed adaptations to diminish uncomfortable and distracting sensory perceptions in classrooms. One study showed that sound-absorbing walls and halogen lighting lead to improved outcomes for students with ASD.

The study started with a two-week baseline to assess the students’ initial performance, then introduced the two interventions at different stages, reassessing performance at each stage. The researchers measured the students’ performance by analyzing recorded segments of the school day for behaviors associated with attention and inattention. Furthermore, students’ perspectives were gathered through interviews and parents provided sensory profiles of the students, which shed light onto different aspects of the students’ responses to the interventions. Overall, the researchers showed that these adjustments to sound and lighting contributed to all-around positive outcomes for the students, who demonstrated improved mood, comfort, classroom engagement, and school performance.

The scope of this study is limited: only four male students were assessed. Regardless, this study illustrates that fairly simple adjustments to spaces, informed by our understanding of the biological causes of ASD symptomatology, can have profound impacts on the educational experience of students with autism.

Although we have made progress as a society in understanding and adapting for people with ASD, this is just the beginning. Along with classroom changes, other spaces such as theaters and workplaces have started to be cognizant of neurodiversity, especially in regards to sensory sensitivities. Adjustments to everyday places such as these will make the world a more comfortable place for people with ASD. These changes will continue to be reliant on research, with real-world interventions informed by a scientific understanding of the sensory, behavioral, and neurobiological changes associated with ASD.

Rachel Davis is a second year PhD student in the Biological and Biomedical Sciences program at Harvard Medical School.

Xiaomeng Han is a graduate student in the Harvard Ph.D. Program in Neuroscience. She uses correlated light and electron microscopy to study neuronal connectivity.

For More Information:

  • To learn more about what it means to be neurodivergent, check out this website
  • Read here for a 2022 review article on ASD. Check out the active research on neurodiversity/ASD going on at Stanford, Harvard, and MIT
  • For more information about the neurochemistry of ASD, check out this 2020 article.  

This article is part of our special edition on diversity. To read more, check out our special edition homepage!

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