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Interoception and Psychosomatic Medicine

  • “Feeling well” “not feeling well”
  • “Physically tense/ relaxed”
  • “Hungry/ full”

The sensory system that detects these physiological states inside the body is called “interoception”.

It is the body’s internal sensor. You may think, “I know what is going on in my body”. However, there are many things you may not be aware of, such as not knowing when you are tired. If you do not feel well, but work too hard without realizing it, you will eventually collapse. This internal sensor is very important for mental/ physical health management.

Two levels of Interoception

There are two main levels of the interoception: unconscious and conscious level of interoception.

  • The unconscious level of interoception, which one is not aware of.
  • The conscious level of interoception, which we are aware of (interoceptive awareness).

The internal state of the body is perceived and adjusted unconsciously, even if we are not consciously aware of it. This is the function of the interoception at the unconscious level. For example, when food enters the stomach and digestion is required, the vagus nerve activates peristalsis and digestive activity in the gastrointestinal tract. The sensing of such a state is not often brought to the conscious mind. This is due to the first, unconscious (subconscious) level of interoception.

However, when too much food enters the stomach and the stomach becomes full to bursting, the feeling of stomach fullness becomes conscious, and the (conscious) realization that “I can’t eat any more” leads to the action of stop eating. This is the second type of interoception at the conscious level. This is sometimes referred to as interoceptive awareness.

Mechanism of Interoception

So how do we perceive the internal state of the body? With the recent development of neuroscience, the mechanisms of interoception/ interoceptive awareness are beginning to be elucidated.

The centers of interoception are located in the insular cortex and the limbic system, the areas responsible for the physiological regulation of the autonomic nervous system. On the functional level of the brain, the level of the limbic system in the middle plays an important role.

This is a slightly deeper level than the normally conscious areas involved in higher mental and cognitive functions, and we are not very aware of it in our daily lives. But we rely on these sensors every day to maintain our physical and mental health.

Awareness of Mind and Body

The sensory perception of mind-body sensations that lead to conscious awareness and action is called “awareness.”

Awareness” of one’s emotions and body is important for physical and mental health and in the treatment of stress-related diseases. If this is not done properly, negative emotions may go unnoticed and not be dissipated, leading to physical ailments. It is also related to eating disorder, as one can overeat despite a full stomach and destroy one’s physical and mental health.

〇 State of decreased emotional awareness: Not aware of what emotions you are feeling = Alexithymia
〇 State of decreased somatic awareness: Not aware of changes in one’s physical condition = Alexisomia

These are called and are one of the characteristic features closely related to psychosomatic disorders. Please refer to the links for each item for more information on these. Interoception is important as the physiological basis of these conditions.

Interoception as the Basis of Emotions

In this way, interoception is the foundation of awareness of the mind and body. In addition, it is believed to be deeply involved in the generation process of emotions such as joy, anger, sadness, and pleasure, and is studied in psychology. Needless to say, emotions are very important in life, and they allow us to lead richer, more human lives.

It is said that “emotions are rooted in the body”. When the body is in good physical condition, good feelings such as joy and happiness are more likely to arise, and when the body is in bad physical condition, negative feelings such as sadness and anger are more likely to arise, as we have all experienced.

When we have a good interoception, we are more aware of our body and mind, our autonomic nervous system functions better, and we are able to make better decisions. In addition, a richer sense of emotion helps us to lead a more fulfilling life.

If this mechanism can be further elucidated, the possibility of improving one’s health by better dealing with one’s mind and body will increase, and it is hoped that a better approach to stress-related diseases can be found in the field of medicine.

(Kanbara K, LABS Psychosomatic Medicine, https://psychosom.net/en/column/interoception/, Jan 2022)

Related Columns, Articles, and Research
Related Projects

Alexisomia Research Association
 http://body-thinking.com/alexisomia/

References

Kanbara, K., Fukunaga, M. Links among emotional awareness, somatic awareness and autonomic homeostatic processing. BioPsychoSocial Med 10, 16 (2016). https://doi.org/10.1186/s13030-016-0059-3