Interoception: The “sixth” sense that shapes our wellbeing

April 16th, 2024

Written by: Serena Chen

Everyone is familiar with the five senses: seeing, smelling, touching, tasting, hearing. But did you know that you also have a sixth sense? This most recently defined sense is called interoception. It is your body’s internal sense, which helps you know when you are hot, cold, hungry, in pain, or any other feeling you have about your body’s physical condition at any point in time1. Even if you were not aware of it, you have been using your interoceptive sense every time you were lying in bed and noticed that your blanket was too warm and thus wanted to kick it off to cool down, or every time you were watching a movie and felt your heartbeat speed up during a high intensity scene, without even needing to move to check your pulse. Like your other senses, interoception is something you use every day, and it would be hard to picture your life without it. But how exactly does interoception work? And how can it help you understand your wellbeing?

What are some examples of your interoceptive sense?

To better understand interoception, it helps to know just how frequently it appears in your life and how useful it is! Have you ever wondered why sometimes you become so hungry or thirsty that you just can’t think about anything else? Maybe this even starts to make you a little hangry. Or have you noticed that sometimes at one moment you feel fine, but the next moment you desperately need to use the bathroom? Or maybe one day you were alone working late into the night and even a small sound would make you jump. These are some examples of interoception that occur consciously2.

Interoception also occurs unconsciously2. This includes the regulation of your heart rate, body temperature, and breathing3,4. It also includes the maintenance of your blood pressure and sugar levels. Interoception is thus vital for not only your everyday life, but also for your continuous survival!

Where does interoception come from?

Interoception arises from the constant communication between your body and your brain2. By just going about your day, you are continuously taking in new information from the environment for your body and brain to process. When this information processing happens, it is like two co-workers discussing a new piece of data and how to best incorporate it into their project goals. If you were to eavesdrop on this conversation between the body and the brain, it would sound something like this: Body: “Ah, I just noticed this and that are changing”, Brain: “Got it, no worries! Try turning this up but keeping that the same.” They do this with the overall goal of keeping you alive and healthy.

Multiple steps need to occur for your body to talk to your brain and vice versa. This message occurs in the form of various chemical signals2. Different parts of your body contain different sensors. For example, sensors in your skin can detect temperature changes or the mechanical force when someone touches you, while sensors in your tongue and gut can detect food intake2. After detection, the information from each part of your body is converted into a chemical signal which is sent to your brain via separate pathways – a process which smartly allows the nature of each signal from the according part of your body to be preserved3. Once in the brain, most signals arrive at similar places before they pass through a region called the thalamus2,3, where they are sorted to be processed by specific groups of neurons around the brain2. This is kind of like how different teachers were assigned to teach you different subjects at school. If you went to your history teacher with a question about something you learned in Spanish class, they likely would not have the right answers for you. This is also why it is important for information to be organized properly in your brain. Only when the information is received and processed correctly can your brain have a nuanced representation of the physiological state of your body. Of course, good communication goes both ways. After processing the body’s message, the brain can then reply by sending more signals to your body that tells it what type of physical reaction it should have2. This stage is when you become aware that someone is touching you or that you haven’t eaten for hours and are now hungry. Overall, this entire process occurs extremely quickly if you think about it – the amount of time it takes for you to realize someone is touching you can be within seconds! This rapid communication is precisely what it takes for interoception – your brain’s perception of the sensations from your body – to occur.

How does interoception affect your emotional state?

Recent research suggests that interoception may also impact behaviors that you may not expect, such as your emotional experiences3,4.

Sometimes, different emotional states are accompanied by similar reactions in your body3. For example, when you are watching a scary movie or when you just found out you won an award for something you worked hard for, your heart rate and breathing may speed up in both cases. However, this physical reaction represents two very different emotions: fear and excitement, respectively. Your body and brain are consistently trying to work out which emotion is being experienced, and the ability to detect these internal signals through interoception is one important factor for this process3. In fact, research has found that people who are less aware about their internal signals also struggle more with identifying which emotion they are experiencing and find it harder to recognize emotions in other people5. On the other hand, people who are more aware of their internal signals may feel their emotions more intensely5. While what it means for there to be individual differences in interoception is something that scientists are still trying to figure out, it is clear that these differences can strongly affect one’s physical and emotional experiences.

Conclusion

The ability to detect your internal signals and use them to regulate your behavior and emotions is something that makes you uniquely-you. Although certain types of interoception are shared amongst all people, no one will experience the world the exact same way that you do. Although studies about the specific differences in interoception between individuals still need to be done, interoception and how it comes to be is a topic that provides valuable insights into how the brain and body work together to generate how you interact with everything around you. As this field of study grows, it can also inform us about how to better treat cases when interoception is impacted. This includes eating disorders, mood disorders, and anxiety disorders6.

References

  1. Craig AD. How do you feel? Interoception: the sense of the physiological condition of the body. Nat Rev Neurosci. 2002 Aug;3(8):655-66. doi: 10.1038/nrn894. PMID: 12154366.
  2. Berntson GG, Khalsa SS. Neural Circuits of Interoception. Trends Neurosci. 2021 Jan;44(1):17-28. doi: 10.1016/j.tins.2020.09.011. PMID: 33378653; PMCID: PMC8054704.
  3. Barker M, Brewer R and Murphy J (2021) What is Interoception and Why is it Important?. Front. Young Minds. 9:558246. doi: 10.3389/frym.2021.558246
  4. Critchley HD, Garfinkel SN. Interoception and emotion. Curr Opin Psychol. 2017 Oct;17:7-14. doi: 10.1016/j.copsyc.2017.04.020. Epub 2017 Apr 23. PMID: 28950976.
  5. Murphy J, Brewer R, Catmur C, Bird G. Interoception and psychopathology: A developmental neuroscience perspective. Dev Cogn Neurosci. 2017 Feb;23:45-56. doi: 10.1016/j.dcn.2016.12.006. Epub 2016 Dec 23. PMID: 28081519; PMCID: PMC6987654.
  6. Khalsa SS, Adolphs R, Cameron OG, Critchley HD, Davenport PW, Feinstein JS, Feusner JD, Garfinkel SN, Lane RD, Mehling WE, Meuret AE, Nemeroff CB, Oppenheimer S, Petzschner FH, Pollatos O, Rhudy JL, Schramm LP, Simmons WK, Stein MB, Stephan KE, Van den Bergh O, Van Diest I, von Leupoldt A, Paulus MP; Interoception Summit 2016 participants. Interoception and Mental Health: A Roadmap. Biol Psychiatry Cogn Neurosci Neuroimaging. 2018 Jun;3(6):501-513. doi: 10.1016/j.bpsc.2017.12.004. Epub 2017 Dec 28. PMID: 29884281; PMCID: PMC6054486.

Cover photo by Amelie on Pexels. 

Handshake photo by fauxels on Pexels.

Leave a comment

Website Powered by WordPress.com.

Up ↑