Breaking Down Autism: A Look at Causes, Effects, and Insights
- Ishaan S Ahuja
- Jan 27
- 3 min read
Autism is a surprisingly common disability: According to the CDC, 1 in 36 people are on the autism spectrum. Given how widespread it is, I was curious about autism’s causes, effects, characteristics, and treatments. Through this blog, I want to do exactly that. I want to dip my toe into the disability that sparked my initial interest in neuroscience and use this blog as the foundation for a short series focusing on this common disability.
Let’s begin with the neuroscience. Autism, formally known as Autism Spectrum Disorder (ASD), is a neurological disability primarily impacting the four main social regions of the brain: the amygdala, orbitofrontal cortex (OFC), temporoparietal cortex (TFC), and the insula. Since there’s a lot to understand each region, let’s break it down:
The amygdala is a structure in the brain made of about 12 million neurons sitting in the temporal lobe. In individuals with autism, the amygdala rapidly grows at a very early age, typically around 6-12 months of age. This leads to a significant enlargement of the amygdala by age two. This results in characteristics such as:
Not being able to make sense of conditions (hot, cold, etc.)
Disinterest in social relationships, i.e., with friends and peers
Not responding to own name
Hypersensitivity to external factors such as noise, smell, etc.
2. The orbitofrontal cortex (OFC) is located in the anterior ventral part of the frontal cortex and is responsible for processing rewards, evaluating potential outcomes, and decision-making. The OFC is in constant interaction with the amygdala. In Autism, an overall hypoactivation of the OFC has been observed, especially in comparison with people who don’t have the disability. Structurally, there is a slight but noticeable difference in the grey matter volume in the region. These two factors put together result in impaired decision-making and planning in people with Autism.
3. The temporoparietal cortex (TPC) comprises parts of the brain's temporal and adjacent parietal lobes. It is responsible for a large portion of the language-related activities of the brain, including integrating sensory information, language processing, understanding spoken words, decoding and understanding writing, and phonology, or mental sound representation of letters and words. Similar to the OFC, an overall hypoactivation of the TPC has been observed in people with autism.
As you may think, this leads to language-related difficulties, such as difficulties in perceiving and understanding situations, difficulty understanding writing and spoken language, and other language deficits. In addition, the hypoactivation of the TPC can cause impaired body representations and motor struggles such as poor posture, poor gait, and overall clumsiness.
4. The insula is the cortex located in the Sylvian fissure of the brain, covered by the orbitofrontal, frontoparietal, and temporal opercula (flaps of tissue in the Sylvian fissure). It encompasses anterior and posterior lobes. The insula has many functions: emotional processing and perception, decision-making, and sensory information integration. Also similar to the OFC and TPC, meta-analyses have revealed that the insula is significantly hypoactive in people with Autism. In addition, the overall cortical surface area is significantly reduced in the brain with ASD.
I hope this blog gives you insight into the neurological connections that underlie this disability impacting over 5 million adults in the US. Having laid out this foundation of neurological causes of Autism Spectrum Disorder, I hope to explore not only the neurological therapies and genetic factors playing a role in Autism but also address the social stigma around Autism and learn about ways society can support people with the disability. My research and writing will be guided by principles of inclusion and awareness, always with the intention of using privilege to support our whole community.
Sources:
https://educationonline.ku.edu/community/social-difficulties-in-autism-spectrum-disorder#:~:text=Two%20Social difficulties in autism spectrum disorder | KU SOEeffective%20community%2Dbased%20interventions,peers%20who%20share%20similar%20interests.
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