As Dr. Stephen Shore said “Autism is here to stay and may be considered a part of the diversity of the human gene pool.” So why is there a lack of research in this area?
Recent decades have shown a massive increase of those being diagnosed with autism, but that does not mean it did not exist before. The awareness just did not exist. Although advances in autism have been incredible over recent decades, the causation is still largely unknown. However, what we do know is that the disorder depends on the interaction between genes, development and environmental factors.
My brother is autistic and due to this, he is anatomically different to me. Not just because I am a female and he is a male or that there is an age difference between us. It is down to his autism and specifically, how his genes have influenced him over the years, as he has grown up. Due to these anatomical differences, the way he communicates, the behaviours he exhibits, as well as the way he moves are all affected. The research that has been carried out has started to delineate answers for the question of why he is the way he is.
There is an area of the brain called the Planum Temporale, and it has been found to be one of the most important functional areas for language and speech. Those who are autistic lack normal symmetry compared to the average neurotypical individual. The left side of this functional area is reduced in autistic individuals. Researchers believe that due to this, individuals with autism have difficulty perceiving and comprehending language. For example, when my brother was younger, his speech was delayed but still to this day, the way he constructs sentences is still not the way an average person would, nor does his speech make logical sense sometimes. Additionally, he perceives and grasps things very literally, so when speaking to him, others need to choose their words wisely. He didn’t even completely understand sarcasm for a great part of his life, so “jokes” around him had to be made carefully.
In addition to this asymmetrical brain region, research has shown that those who are autistic, as well as those who suffer from disorders that contain repetitive behaviours such as OCD, have an enlarged caudate volume. The caudate is deep inside the brain, near the thalamus, and plays a vital role in neurological functions such as planning the execution of movements, as well as in learning, memory and emotion. The enlarged caudate volume is thought to be the anatomical reason for why autistic people have ritualistic – repetitive behaviours, meaning behaviours that follow a similar pattern every time. So when you think of the stereotyped behaviours an autistic person may present with, there is a chance they are due to this enlarged caudate volume. For example, my brother goes through phases of saying the same phrase or even word over and over again. I remember a time when my family and I heard “macaroni cheese, makka cheese, macaroni cheese” repeated numerous times because these words were just stuck in his head, like a broken record player. Aside from repeating words and phrases, behaviours such as head banging and stimming are also repetitive behaviours. Stimming, otherwise known as self-stimulatory behaviour, is repetitive or unusual body movement or noises often done to regulate the person and their thinking. For example, hand-flapping or rocking back and forward.
Aside from the brain specifically, there has been evidence of disorder of growth of the neural systems and connections among the rest of the body. This has been seen to affect the immune system of autistic people. It is thought that there is initially a problem with growth hormones, so when the body is developing in utero, certain systems and organs’ development are not being regulated properly, causing problems and abnormalities. For example, causing problems with the neuronal connections in the Planum Temporale, which normally occur when someone is speaking to you, and these connections usually help you comprehend what the other person is saying. Cell Therapy is now being looked into in regards to this abnormality, which in turn raises a lot of ethical questions, such as “is it ok to be different and have a disability?”. If we can in the future use Cell Therapy to change these abnormalities, it could possibly enforce this stigma around disabilities and trying to “fix” people who have them.
Research has also been carried out on bone thickness - reduced bone thickness could be one of the many reasons for why autistic people have very poor balance. There have been multiple occasions when my brother has fallen over for no apparent reason, along with not being the best at balancing on a beam in gymnastics. However, the scientific research regarding bone thickness is currently quite weak.
In conclusion, in order for us to fully understand those that are autistic, we need to know where the root of the difference comes from. After all, autism is a part of the human gene pool.
-Carena Guthrie @carenaguthrie
References
https://www.sciencedirect.com/science/article/pii/S0278584699000202
https://www.sciencedirect.com/science/article/pii/S0361923003002235
https://www.hindawi.com/journals/sci/2013/623875/
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