Autism Spectrum Disorder: How Differences in Brain Function contribute to Symptomatic Behavior

Posted by J Huffine on February 26, 2020

1j resizedAs a wilderness therapist at Evoke Cascades, I often work with adolescent males who have been diagnosed with Autism Spectrum Disorder (ASD). A couple of years ago, I wrote a blog on this disorder and how wilderness therapy can help.

In this current blog I discuss some research on the biological basis or underpinnings of ASD. Knowledge of these factors can contribute to the understanding of why individuals on the autism spectrum exhibit certain social, emotional, and behavioral difficulties. Understanding the cause of any disorder can lead both to an understanding of the symptom presentation as well as guide treatment planning such as selecting the most effective approach to help such individuals function more effectively in society.

First, some statistics:
 About 1 in 59 children has been identified with autism spectrum disorder
(ASD) according to estimates from CDC’s Autism and Developmental
Disabilities Monitoring (ADDM) Network.
 ASD is reported to occur in all racial, ethnic, and socioeconomic groups.
 ASD is about 4 times more common among boys than among girls.
 Studies in Asia, Europe, and North America have identified individuals with
ASD with an average prevalence of between 1% and 2%.

There are a number of areas and ways in which individuals with ASD typically
-social impairment
-sensory integration issues
-narrow range of interest
-high need for routine
-emotional dysregulation
-speech and language peculiarities
-non-verbal communication problems
-gross motor skill delays
I would like to talk specifically about some of the underlying biological bases that
contribute to the social, emotional, and communication difficulties.

ASD is thought to be caused by complex interactions among genetics, certain prenatal and perinatal factors, as well as environmental factors. Whatever the combination of circumstances, these contributing factors result in neurological and anatomical anomalies in the central nervous system. Brain imaging studies indicate that cortical
circuits appear to be altered in several disorders, including autism, specifically in brain areas that mediate cognitive, emotional and social behaviors.

Much of the research into neurological causes has been on the amygdala, which is the area of the brain that dictates the emotional response to specific situations in which an individual is placed. The amygdala selects emotional responses from the limbic system and relays them to the cerebral cortex. Brain studies conducted on people with ASD indicate that the connections between these brain regions are altered and not fully functional due to “aberrant wiring.” The result is that people with ASD can experience extreme emotional reactions even to seemingly trivial objects or events, especially if the event occurs suddenly and unexpectedly. This “over reacting” creates significant
distress for the individual as well as for other people present.

Neuroimaging studies also find abnormal patterns in brain activity in dorsal parietal regions associated with the ability to switch from one activity to another in several major neurological and psychiatric disorders including autism. This research may explain why people who have ASD favor routines, since routines and patterns provide both predictability and a perception of being in control. Unexpected changes, and even expected transitions are often very difficult. In fact, any event that requires emotional processing can be difficult to manage internally. That is why so many individuals with ASD have patterns of behavior that are viewed as controlling, a need to “have it my way.” Controlling external events, people, situations, objects, etc. is a way to achieve some internal control of feelings, though it may present as oppositional. (

Another area of research has examined the role of mirror neurons, which enable an individual to mirror another person’s actions. A mirror neuron is what enables a baby to smile in reaction to a mother’s smile, for example. More elaborate neuropathways are created by mirror neurons that may contribute to higher brain functioning and development such as language, learning from others, and the ability to recognize emotional states in others (and self) as an individual develops. Studies of children with ASD have discovered that mirror neurons in ASD individuals respond in a different manner than in the general population, resulting in difficulties interpreting the
emotional states of others as well as identifying emotional states in one’s self. ASD individuals often “say the wrong thing,” misinterpret situations and act in ways that are inappropriate for the situation. Their own non-verbal responses, e.g., facial expressions and body language, may appear odd, stiff or awkward because they haven’t learned through a neurotypical learning process of mimicking.

These are a few examples of how differences in brain anatomy and physiology contribute to symptoms often associated with ASD: social difficulties, emotional regulation problems, need for adherence to routine, controlling behavior, a focus on one specific interest. Much of what is considered negative, oppositional or problematic behavior is actually an attempt to control one’s own anxiety. In mild to moderate ASD these biological differences do not prevent someone from learning more effective coping skills and a better understanding of social situations - it just makes the learning process harder, the learning curve steeper. And the learning usually doesn’t occur through the natural course of living. In fact, the reaction of others can be quite negative towards the individual which, unfortunately, gives that person beliefs that s/he is inadequate, bad or defective, thus leading to internalized shame.

The “treatment” for helping individuals develop skills to function more effectively often needs to be a step by step, direct process. If someone is not a natural at something, say foreign languages, then they may never learn the unfamiliar language merely by being immersed in a setting where it is spoken. It must be learned in an often tedious, but effective step by step manner. I believe it is important to understand that individuals with ASD are not being difficult “just because they want to be.” They benefit from understanding and patience just like everyone else. Maybe more so.

 Purves et al, Neuroscience, sixth edition, Oxford University Press, 2018.


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