Interoception: The Eighth Sensory System

“Difficulties with interoception help to explain why I have a hard time identifying my exact symptoms when I am sick, why sometimes I seem to eat snack after snack without feeling full and why I get upset so quickly, because I don’t feel it until I’m already far into the storm of the discomfort and frustration. —Chloe, 23-year-old with autism

 

Sensory differences are common in people with autism. These differences can occur within any or all of the seven systems commonly discussed: smell, sight, sound, touch, taste, vestibular and proprioception. However, emerging research reveals that these seven senses are not the only ones that can be affected1,2 .There is an additional sense, one  that has been studied for decades in other fields, but is much less talked about in the field of autism. This eighth sensory system is called interoception.

What is interoception? Interoception allows you to feel what is going on inside of your body. For example, take a moment to consider the following:

  • Is your heart beating fast or slow?
  • Are you breathing deeply or shallowly?
  • Do you have to go to the bathroom?
  • Is your stomach empty, full or content?
  • Do you have pain anywhere?
  • Are your muscles tense or loose?

Many people are able to easily and clearly feel the above sensations, among others, with the help of this vital sensory system called Interoception.

How does the interoceptive system work? The interoceptive system has specialized cells or receptors located throughout most of the tissues in the body, in your heart, lungs, stomach, bladder, genitals, muscles, skin, bones and so forth. These receptors gather information and send it to an area in the brain called the insula. The insula uses the incoming information to help you identify conditions like pain, hunger, fullness, itch, coldness, warmth, nausea, need for the bathroom, physical exertion, sexual arousal, anger, calmness, distraction or fear. Interoception allows you to answer the question, “How do I feel?” 3,4

Why is interoception important? Research has found that people with well-functioning insula have better levels of Interoceptive Awareness (IA) which is a term used to describe the degree that one is aware of their internal body signals5. IA requires the ability of the following two parts:

  1. NOTICE internal sensations
  2. GIVE MEANING to the sensations6

For example, you may notice a dry feeling in your mouth and throat and know that it means you are thirsty. Or you may notice shakiness in your muscles, a quivering stomach and faster heart and know that it means that you are nervous.

Interoceptive awareness and self-regulation. Clear internal information is essential for management of both body states like hunger, thirst and need for the bathroom as well as management of emotions like anxiety, anger. Specifically speaking, if you are able to notice and give meaning to internal signals it, in turn, alerts you that your internal balance is off and motivates us to take action — to do something that will restore the internal balance and help us feel more comfortable. For example, if you feel hungry—you are urged to eat; if you feel thirsty – you are urged to get a drink; if you feel cold – you are urged to get a jacket; if you feel the need to urinate – you are urged to seek a bathroom; if you feel anxious – you are urged to seek comfort; if you feel frustrated—you are urged to seek help. Interoception underlies your urge for action7. If you clearly feel that your internal balance is off, you are motivated to act, to seek immediate relief from the discomfort caused by the imbalance.

On the contrary, if internal sensations are confusing, vague or absent, it can lead to a delayed or nonexistent urge for action. For example, if you do not clearly feel the need to urinate until it is very extreme—it may lead to an accident; if you do not clearly feel building body warmth—it may lead to overheating; if you do not clearly feel the beginning clues of sensory overload—it may lead to sensory shut-down; if you do not clearly feel clues of building anger—it may lead to meltdown. The following are examples of the impact of reduced IA:

“I do not realize that I am getting angry until I am exploding with anger. By then it is too late. I can’t control it.”– Jason, a 9-year-old boy with autism

“My daughter did not feel her signs of hunger. I bet she would have gone days without eating if I did not remind her to eat. The same thing for thirst—she did not feel that urge to drink that many of us experience. It was terrifying as a mother. I constantly worried if she was getting enough food and water. We worked really hard on developing the awareness of her body signals, which has had a tremendous pay-off.” —Julie, mother of an 8-year-old daughter with autism

“My son walked around on a broken leg for 2 days without a single complaint or indication of pain. It wasn’t until I noticed the swelling and bruising, that I realized he had a serious injury.”—Nick, father of a 14-year old son with autism

 “A lot of times the inside of my body feels like one of those glitter timers—the ones that you can shake and the glitter goes every which way. I feel so many different things at once and I’m not sure what is important. It is very overwhelming.”—Gracie, a 13-year-old with autism

“Even though my son is extremely verbal, when he is sick, he is usually not able to explain his specific symptoms to me or the doctor. He can tell me that he feels yucky, but being able to pinpoint exactly where he feels sick and describe exactly what it feels like is very difficult. That sure makes it hard to get him proper medical care.” —Sam, father of a 9-year-old boy with autism

“I can feel a general sense of negative emotion, but I often have no idea which emotion it is and why it is happening.” —Ward, a 50-year-old with autism

What do we know about interoception and autism spectrum disorder? Many studies have revealed insula differences in individuals with autism8-13. Given that the insula is the interoception center in the brain, this provides a brain-based explanation for the interoceptive difficulties reported by many individuals with autism. In addition, two recent studies have directly examined the IA levels of individuals with autism1,2. Both studies, one based on measures of self-report1 and the second based on two different heartbeat awareness tasks combined with a measure of self-report2, found individuals with autism to have lower levels of IA compared to controls. Interestingly, the autistic participants who scored the lowest on the tasks of IA also were found to have higher levels of anxiety and emotional regulation difficulty2. Although more research is needed, the emerging picture from these studies is that interoceptive difficulties exist and impact the lives of many individuals with autism.

Can interoceptive awareness be improved? The good news is yes, IA can be improved. Techniques derived from mindfulness and other forms of meditation have been found to be evidence-based interventions to enhance IA14-17. Interestingly, the insula, or the interoceptive center in the brain, is strongly activated during meditation18,19. Furthermore, individuals who participate in regular meditation have been found to have superior insula functioning, both structurally and in terms of activity levels20-22.  Thus, a series of strategies that incorporate principals from mindfulness have been created for use with individuals with autism. These strategies, named IA Builders, are adapted versions of often times abstract mindfulness concepts and aim to improve IA in a visual, engaging and concrete manner. Many children and adults with autism have experienced great outcomes through the use of IA Builders. Currently, several of these strategies are under formal study.

Conclusion. Interoception has a major influence on health, well-being and self-regulation and therefore emerges as an important consideration in the autism field. Learning more about the interoceptive experiences of individuals with autism is crucial and will allow us to gain a better understanding of the differences in neurology.

The brand-new book Interoception: The Eighth Sensory System (aapcpublishing.net) delivers an in-depth look at interoception including research, assessment and intervention tips. Join the Facebook group: Interoception: The Eighth Sensory System to share experiences, ask questions & get the most current information and research surrounding interoception.

Kelly Mahler MS, OTR/L, earned a MS in Occupational Therapy, as well as a Post-Professional Pediatric Certificate from Misericordia University, Dallas, PA. She is an occupational therapist and autism consultant who supports school-aged individuals and young adults with autism spectrum disorders. Mahler is also co-founder of Destination Friendship, an organization dedicated to providing multidisciplinary social skill groups within the community. Mahler is a professor of Occupational Therapy at Elizabethtown College, Elizabethtown PA. She is actively involved in multiple research projects pertaining to interoception. Mahler has presented numerous seminars and workshops at the international and national levels.  Additionally, she has authored many books and instructional materials, including:

  • Interoception: The Eighth Sensory System
  • The Comprehensive Assessment of Interoceptive Awareness
  • Sensory Issues and High Functioning Autism (with Myles and Robbins) —winner of National Parenting Publications Bronze Medal
  • Destination Friendship: Developing Social Skills for Individuals with Autism Spectrum Disorders or Other Social Challenges (with Benton, Hollis, and Womer)
  • Hygiene and Related Behaviors for Children and Adolescents With Autism Spectrum and Related Disorders — winner of Mom’s Choice Awards Gold Medal.

 

  1. Fiene, L., & Brownlow, (2015). Investigating interoception and body awareness in adults with and without autism spectrum disorder. Autism Research. doi:10.1002/aur.1486
  2. Garfinkel, S. N., Tiley, C., O’Keeffe, S., Harrison, N. A., Seth, A. K., & Critchley, H. D. (2016). Discrepancies between dimensions of interoception in autism: Implications for emotion and anxiety. Biological psychology, 114, 117-126.
  3. Craig, D. (2002). How do you feel? Interoception: The sense of the physiological condition of the body. Nature Reviews Neuroscience, 3(8), 655-666.
  4. Craig, D. (2009). How do you feel – Now? The anterior insula and human awareness. Nature Reviews Neuroscience, 10(1).
  5. Critchley, D., Wiens, S., Rotshtein, P., Öhman, A., & Dolan,  R.  J.  (2004). Neural systems supporting interoceptive awareness. Nature Neuroscience, 7(2), 189-195.
  6. Mahler, K. (2016). Interoception: The eighth sensory system: Practical Solutions for improving self-regulation, self-awareness and social understanding of individuals with autism spectrum and related disorders. Shawnee Mission, KS: AAPC
  7. Jackson, S. R., Parkinson, A., Kim, S. , Schüermann, M., & Eickhoff, S. B. (2011). On the functional anatomy of the urge-for-action. Cognitive Neuroscience, 2(3-4), 227-243.
  8. Radeloff, D., Ciaramidaro, A., Siniatchkin, M., Hainz, D., Schlitt, S., Weber, , … & Freitag, C. M. (2014). Structural alterations of the social brain: A comparison between schizophrenia and autism. PloS One, 9(9), e106539.
  9. Di Martino, A., Ross K., Uddin L., Sklar A., & Costellanos, X. (2009). Functional brain correlates of social and nonsocial processes in autism spectrum disorders: An activation likelihood estimation meta-analysis. Biological Psychiatry, 65, 63-74.
  10. Di Martino, A., Yan, G., Li, Q., Denio, E., Castellanos, F. X., Alaerts, K., & Milham, M. P. (2014). The autism brain imaging data exchange: Towards a large-scale evaluation of the intrinsic brain architecture in autism. Molecular Psychiatry, 19(6), 659-667.
  11. Uddin, L. Q., Supekar, K., & Menon, (2013). Reconceptualizing functional brain connectivity in autism from a developmental perspective. Frontiers in Human Neuroscience, 7.
  12. Dickstein, D. , Pescosolido, M. F., Reidy, B. L., Galvan, T., Kim, K. L., Seymour, K. E., Laird, A. R., Di Martino, A., & Barrett, R. P. (2013). Developmental meta-analysis of the functional neural correlates of autism spectrum disorders. Journal of the American Academy of Child & Adolescent Psychiatry, 52(3), 279-289.
  13. Nomi, J. S., & Uddin, L. Q. (2015). Developmental changes in large-scale network connectivity in autism. NeuroImage: Clinical, 7, 732-741.
  14. Daubenmier, J., Sze, J., Kerr, E., Kemeny, M. E., & Mehling, W. (2013). Follow your breath: Respiratory interoceptive accuracy in experienced meditators. Psychophysiology, 50(8), 777-789.
  15. Farb, N. A., Anderson, A. K., Mayberg, H., Bean, J., McKeon, D., & Segal, V. (2010). Minding one’s emotions: Mindfulness training alters the neural expression of sadness. Emotion, 10(1), 25.
  16. Grossman, , Niemann, L., Schmidt, S., & Walach, H. (2004). Mindfulness-based stress reduction and health benefits: A meta-analysis. Journal of Psychosomatic Research, 57(1), 35-43.
  17. Khalsa, S. S., Rudrauf, D., Damasio, A. R., Davidson, R. J., Lutz, A., & Tranel, (2008). Interoceptive awareness in experienced meditators. Psychophysiology, 45(4), 671-677.
  18. Farb, N. A., Segal, Z. V., Mayberg, H., Bean, J., McKeon, D., Fatima, Z., & Anderson, A. K. (2007). Attending to the present: Mindfulness meditation reveals distinct neural modes of self-reference. Social Cognitive and Affective Neuroscience, 2(4), 313-322.
  19. Lutz, , Slagter, H. A., Dunne, J. D., & Davidson, R. J. (2008). Attention regulation and monitoring in meditation. Trends in Cognitive Sciences, 12(4), 163-169. doi:10.1016/j.tics.2008.01.005
  20. Hölzel, B. K., Ott, U., Gard, , Hempel, H., Weygandt, M., Morgen, K., & Vaitl, D. (2008). Investigation of mindfulness meditation practitioners with voxel-based morphometry. Social Cognitive and Affective Neuroscience, 3(1), 55-61.
  21. Hölzel, B. K., Carmody, , Vangel, M., Congleton, C., Yerramsetti, S. M., Gard, T., & Lazar, S. W. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research: Neuroimaging, 191(1), 36-43.
  22. Lazar, W., Kerr, C. E., Wasserman, R. H., Gray, J. R., Greve, D. N., Treadway, M. T., & Fischl, B. (2005). Meditation experience is associated with increased cortical thickness. Neuroreport, 16(17), 1893-1897.

Additional Reading

Craig, A. D. (2002). How do you feel? Interoception: the sense of the physiological condition of the body. Nature Reviews Neuroscience, 3(8), 655-666.

Craig, A. D. (2003). Interoception: The sense of the physiological condition of the body. Current Opinion in Neurobiology, 13(4), 500-505.

Craig, A. D. (2009). How do you feel – Now? The anterior insula and human awareness. Nature Reviews Neuroscience, 10(1).

Craig, A. D. (2014). How do you feel? An interoceptive moment with your neurobiological self. Princeton, NJ: Princeton University Press.

Critchley, H. D., Wiens, S., Rotshtein, P., Öhman, A., &  Dolan,  R.  J.  (2004). Neural systems supporting interoceptive awareness. Nature Neuroscience, 7(2), 189-195.

Daubenmier, J., Sze, J., Kerr, C. E., Kemeny, M. E., & Mehling, W. (2013). Follow your breath: Respiratory interoceptive accuracy in experienced meditators. Psychophysiology, 50(8), 777-789.

Farb, N. A., Anderson, A. K., Mayberg, H., Bean, J., McKeon, D., &   Segal, Z. V. (2010). Minding one’s emotions: Mindfulness training alters the neural expression of sadness. Emotion, 10(1), 25.

Farb, N. A., Segal, Z. V., Mayberg, H., Bean, J., McKeon, D., Fatima, Z., & Anderson, A. K. (2007). Attending to the present: mindfulness meditation reveals distinct neural modes of self-reference. Social cognitive and affective neuroscience, 2(4), 313-322.

Grossman, P., Niemann, L., Schmidt, S., & Walach, H. (2004). Mindfulness-basedstressreductionandhealthbenefits: Ameta-analysis. Journal of Psychosomatic Research, 57(1), 35-43.

Hölzel, B. K., Ott, U., Gard, T., Hempel, H., Weygandt, M., Morgen, K., & Vaitl, D. (2008). Investigation of mindfulness meditation practitioners with voxel-based morphometry. Social Cognitive and Affective Neurosci- ence, 3(1), 55-61.

Hölzel, B. K., Carmody, J., Vangel, M., Congleton, C., Yerramsetti, S. M., Gard, T., & Lazar, S. W. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research: Neuroimaging, 191(1), 36-43.

Jackson, S. R., Parkinson, A., Kim, S. Y., Schüermann, M., & Eickhoff, S. B. (2011). On the functional anatomy of the urge-for-action. Cognitive Neuroscience, 2(3-4), 227-243.

Khalsa, S. S., Rudrauf, D., Damasio, A. R., Davidson, R. J., Lutz, A., & Tranel, D. (2008). Interoceptive awareness in experienced meditators. Psychophysiology, 45(4), 671-677.

Khalsa, S. & Lapidus, R. (2016) Can Interoception Improve the Pragmatic Search for Biomarkers in Psychiatry? Front. Psychiatry 7:121. doi: 10.3389/fpsyt.2016.00121.

Lazar, S. W., Kerr, C. E., Wasserman, R. H., Gray, J. R., Greve, D. N., Tread- way, M. T., … Fischl, B. (2005). Meditation experience is associated with increased cortical thickness. Neuroreport, 16(17), 1893-1897.

Lutz, A., Slagter, H. A., Dunne, J. D., & Davidson, R. J. (2008). Attention regulation and monitoring in meditation. Trends in Cognitive Sciences, 12(4), 163-169. doi:10.1016/j.tics.2008.01.005

Mahler, K. (2016). Interoception: The Eighth Sensory System: Practical Solutions for Improving Self-Regulation, Self-Awareness and Social Understanding of Individuals With Autism Spectrum and Related Disorders. Shawnee Mission, KS: AAPC Publishing

Mehling, W. E., Price, C., Daubenmier, J. J., Acree, M., Bartmess, E., & Stewart, A. (2012). The multidimensional assessment of interoceptive awareness (MAIA). PLoS One, 7(11), e48230. doi:10.1371/journal. pone.0048230

Miller L., Anzalone M., Lane S., Cermak S., Osten E. (2007a). Concept evolution in sensory integration: a proposed nosology for diagnosis. Am. J. Occup. Ther. 61, 135–140

 

 

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