Brain with magnifying glass

Autism is a complex condition that is not yet well understood. However, researchers have made progress in understanding how the brains of people with autism differ from those of neurotypical individuals.

Several brain differences have been identified in people with autism. These include differences in the structure and function of certain brain regions, as well as differences in overall brain size.

Brain differences in people with autism


The cerebellum is a small, round structure located at the back of the brain, beneath the cerebral cortex. It is responsible for coordinating movement and balance and helping to regulate some cognitive functions such as attention and language.

People with autism often have cerebellum size, shape, and function abnormalities. These abnormalities can lead to problems with motor skills, balance, and coordination, as well as difficulties with cognition, social interaction, and communication.

Some research suggests that the cerebellum may be involved in the development of autism. For example, one study found that people with autism have a significantly smaller cerebellum than those without the condition.

Researchers have also found differences in the structure and function of the cerebellum in people with autism. In one study, autistic people showed less activity in the cerebellum during a task that required them to plan and execute movements.

It is not clear exactly how these differences in the cerebellum contribute to the symptoms of autism. However, they may play a role in the development of the condition and its associated difficulties.

Hippocampus and Amygdala

The hippocampus is a seahorse-shaped structure located in the brain’s medial temporal lobe. It is important for memory formation and navigation. The amygdala is a small, almond-shaped structure located in the temporal lobe. It is involved in processing emotions, such as fear and anxiety.

People with autism have differences in both of these structures. The hippocampus is larger in people with autism, while the amygdala is smaller. These differences may be due to genetic factors or differences in early brain development.

The larger hippocampus in people with autism may be related to difficulties forming new memories. This may explain why some people with autism have trouble learning new information or recalling past experiences. 

The smaller amygdala in people with autism may be related to increased anxiety and fearfulness. This may explain why some people with autism avoid social situations or become overly upset when routines are changed.

Lobes of the Cerebrum

The cerebrum is the largest part of the brain. It is divided into two hemispheres – left and right – that are connected by a bundle of nerve fibers, the corpus callosum. Each hemisphere is further divided into four lobes: frontal, parietal, temporal, and occipital.

One common difference is that people with autism tend to have a larger than average corpus callosum. 

A larger corpus callosum has been linked to better communication between the brain’s two hemispheres. This may explain why some people with autism are good at problem-solving and have “left-brain” strengths in addition to their “right-brain” strengths.


The ventricles are the four cavities in the brain that contain cerebrospinal fluid. They are located in the two cerebral hemispheres, as well as in the cerebellum. The ventricles help to protect the brain and spinal cord by cushioning them from impact.

Evidence suggests that people with autism have larger ventricles than those without autism. 

It is not clear why people with autism have larger ventricles. It could be due to a genetic predisposition, or it could be that the ventricles simply grow larger in response to the challenges posed by autism. Regardless of the cause, this difference in brain anatomy may help to explain some of the symptoms associated with autism.

Caudate nucleus

The caudate nucleus is a key structure in the brain that has been linked to autism. A recent study found that people with autism have reduced volumes of the caudate nucleus compared to those without autism.

The caudate nucleus is important for several functions, including learning, memory, reward, motivation, and emotion. It has been suggested that the reduced volume of the caudate nucleus in people with autism may be linked to the impaired social and communication skills characteristic of the condition.


The cortex is the outermost layer of the brain and is responsible for higher-order thinking, such as decision-making and planning. It is also responsible for processing bodily sensory information, such as touch, sight, and sound.

People with autism tend to have a thicker cortex than people without autism. This difference may help to explain why people with autism often have difficulty with social interaction and communication. The thicker cortex may also be associated with the repetitive behaviors and restricted interests characteristic of autism.

Symptoms of autism 

Communication Problems

Most people with autism have difficulty with communication. They may not be able to start a conversation or keep one going. Or, they may say things that are unrelated to what others are saying. 

This can make it hard for them to interact with other people, especially in groups. Many people with autism also have trouble understanding nonverbal communication, such as facial expressions and body language.

Repetitive Motions

Many people with autism engage in repetitive motions, such as rocking back and forth, flapping their hands, or twirling their fingers. They may also become obsessed with parts of a toy or an object, such as the spinning wheels on a car. 

These motions can be soothing to them and help them deal with anxiety or other emotions. But they can also interfere with daily activities, such as eating or getting dressed.

Problems with Social Interactions

People with autism often have trouble with social interactions. They may not understand the give-and-take of conversation. Or they may not be interested in other people at all. 

Many people with autism also have difficulty understanding other people’s feelings or appropriately reacting to them. For example, they may laugh if someone else is sad or hurt.

People with autism may also have difficulty making and maintaining eye contact. And they may prefer to be alone rather than with others.

Key Takeaways

While the exact cause of autism is unknown, the growing body of evidence suggesting differences in brain structure provides a potential explanation for some of the symptoms associated with the condition. 

People with autism often have difficulty with social interaction, communication, and repetitive behaviors. It is possible that the differences in brain structure contribute to these symptoms by affecting the way information is processed.


If you are ready to work with the best ABA therapy provider in New York, New Jersey or Indiana, give us a call at (732) 402-0297. Our dedicated team is ready to help and we will treat you like family.

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