Most of us know about the seven senses – sight, hearing, smell, taste, touch, vestibular, and proprioception. There is also a lesser-known sense, the eighth sense, called interoception. This sense helps a person understand what is going on inside of the body like hunger, thirst, feeling hot or cold, fatigue, or a full bladder. It also affects the ability to interpret emotions; butterflies in the stomach may not be felt as anxiety or nervousness. Not understanding this sense can make self-regulation a challenge. It can also be the cause of eating and toileting difficulties, something we frequently see in people with autism.
Muscles and joints have receptors that tell you where your body parts are. Interoception works much the same way, but the receptors are in your organs including your skin. These receptors send messages about the body to the brain, helping to regulate vital functions such as hunger, thirst, digestion, or heart rate.
Understanding these bodily feelings can help with interpretation of what’s going on inside the body. If your bladder is full, you need to urinate. If your heart is beating fast, you may need to take a few deep breathes to slow it down.
People with ASD may have difficulty making sense of this information. They may not be able to tell when they are feeling pain or fatigue. An itch may be felt as pain or pain may feel ticklish. They may not get the feeling of having to defecate and hold on to a bowel movement, which can lead to constipation.
Interoception also affects the interpretation of emotions. Emotions may not be “felt”. If you can’t tune in to the body cues that help interpret emotion, it’s harder to identify the emotion. It’s important to understand this aspect, because not feeling emotions affects a person’s behavior. For example, a child may not recognize fear because he doesn’t recognize that tense muscles, shallow breathing and a racing heart equals fear. My daughter recently told me that when she was in elementary school, she could only feel happiness or just “blank”. This lack of interoceptive awareness could explain explosive behavior because it’s not until the emotions are so big that an eruption occurs.
This is a short introductory video on interoception that explains what it’s all about.
Interoceptive challenges will also affect the ability to self-regulate. If you don’t know that you’re hungry, thirsty or have a full bladder, you may feel uncomfortable but not know why. Frustration can build when you can’t explain what is troubling you.
When the interoceptive sense is impaired, certain responses may not be regulated. For example, this could be the reason why an older child wets the bed. Not feeling “off” can lead to a meltdown. The real source of discomfort can’t be pinpointed. It’s important to be aware of this fact in order to discover the source of unexplained behavior. For example, when someone tells me a person is chewing on a hard object like wood, the first question I ask is about dental care. Could there be a cavity? Tender gums? A piece of food stuck between the teeth?
I can remember my good friend, Judy Endow, telling me about a 9 year old girl who kept banging her head so much that she required a helmet for head protection. She actually had head lice that no one had detected. Once that was solved, the head banging stopped.
My daughter once pulled her hair out all around one ear, completely bald. She was later diagnosed with an ear infection. She had never complained or cried to me about the pain.
Understanding interoception can be the key to interpreting unexplained behavior or difficulties with bodily functions. With more research occurring around this topic, we will certainly understand more about this eighth sense and the role it plays in individuals with ASD in the years to come.
Thank you to Maureen Bennie, Director of The Autism Awareness Center for your kind permission to use this article.