Written in January 2022

You can be forgiven for not knowing what interoception is. As I type this, the word is underlined in squiggly red, so not even the Open Office dictionary knows what it is.

Interoception is one of the senses; there are many more than the standard five. Some people will say there are eight, while others claim to be able to name over twenty. I'm in the “eight” camp but open to learning more (just like you if you're reading this).

Interoception is the sense which allows us to experience internal feelings and sensations, like hunger, thirst, needing the toilet, and even emotions. It's partly linked to the touch sense (taking touch a little further, helping us determine whether we like or loathe a certain touch-feeling) but is separate from the main external stimulus-processing senses we are familiar with. Many of the internal systems of the body feed into interoception, including our cardiovascular system, digestive, thermal regulation, immune and respiratory systems. Our interoceptive sense also automatically processes the messages and effects an action, or at least it does when its working normally.

A disconnected interoceptive sense is involved in a number of conditions including anxiety, eating disorders and neurodiverse conditions - “normal/healthy” people are mostly not even aware of their interoceptive sense because everything's working as it should. For most people it's a subconscious system which sends messages to the brain and effects action. We know autistic people often have a delay in sensory processing, an impairment, or even overactive sensory processing, so it follows that we experience difficulties in interoceptive processing.

An example is needing the toilet. For most people they experience the message from the interoceptive sense that they need to go, and will stop what they're doing to attend to the need. For people with interoceptive difficulties these messages are scrambled, so they may never get the message that they need to go, or may be unable to act on that message and initiate the task. In autistic people the interoceptive sense can be suspended or blocked when we are engaged with our special interest (spin), leading to us spending hours on a task, totally engrossed and needing a reminder to eat, drink, and use the loo.

My interoception (on a sensory experience and processing level) is mildly impaired, with some aspects more impaired than others. When I am getting a message from my interoceptive sense it can be hard to initiate the actual task and I may lose focus on what I'm doing when the message breaks through. This often means I have to immediately attend to the message before I can focus on anything else. You may experience the “hangry” feeling where you can't do anything until you eat, and it's a bit like this (except more distressing).

My thermal regulation is terrible, and it can take me hours to cool down after exercise or a shower. I don't get hunger signals like most people, and either don't experience them at all, or have very sudden onset of intense hunger and an inability to sort out food because of the all-encompassing flood of “HUNGRY” signals I'm getting. I have tried to bypass the automation of interoception by consciously thinking about whether I am hungry, but this doesn't work, I don't get an answer from inside.

In dangerous situations, most people rely on their interoception to raise the heart rate, release adrenaline and effect the fight or flight response. My reaction in similar situations is completely different and I don't get these effects. They can appear much later, or not at all.
 

Interoception is also partly responsible for dissociation. That feeling that you're in autopilot and not in control of what you're doing or what is happening is the interoceptive sense not being able to get messages through. The dissociation that people with anxiety, PTSD and autism spectrum conditions experience is directly linked to a malfunctioning interoceptive sense. Interoception can be impaired either through a natal condition, or as the result of trauma.
 

There is some research around whether improving people's relationship with their interoceptive sense can help fight addiction, anxiety and depression, and even improve socialisation by giving people the tools to interpret and decode interoceptive signals more effectively. A study of autistic adults conducted by Professor Hugo Critchley showed that people who consciously studied their heartbeat showed a reduced incidence of anxiety three months after the study ended compared to the control group; 31% of participants were actually considered to have recovered from an anxiety disorder at this stage.

Being more aware of the messages our bodies are sending us is useful for everyone, regardless of neurotype. People living with chronic pain and fatigue conditions can improve their symptoms and quality of life by listening to their bodies and acting on the messages that are being sent. This helps with pacing and activity choice which can ensure people don't overdo it and suffer more symptoms as a result.

For autistic people, a conscious focus on receiving and interpreting interoceptive signals can improve symptoms (and therefore our quality of life) in terms of socialisation and dealing with anxiety inducing symptoms. I'm not sure there's a way of training my brain to recognise when I am too hot and cool me down in a reasonable time frame – if the link isn't there to start with I don't think it can be created out of nothing.

Further reading: https://www.frontiersin.org/articles/10.3389/fpsyg.2019.02589/full

https://www.theguardian.com/science/2021/aug/15/the-hidden-sense-shaping-your-wellbeing-interoception