When we talk about the senses, we generally think of the five dedicated to the perception of the outside world, that is, sight, hearing, smell, taste and touch. Thanks to them we perceive images, sounds, smells and pheromones, flavors, temperature and physical contact.
However, we often don’t pay attention to an important detail. We can also perceive our interior. We notice headaches, nausea, internal itching, heart rate or muscle pain. And this is attributable to another sense: interoception In this article we are going to do a brief analysis of this concept.
We understand by interoception the perception of the internal state of the organism, providing information on the functioning or dysfunction of the viscera and internal organs It is a sense that helps us maintain homeostasis or body balance. Although often undervalued, interoception is vital for survival: thanks to it we can perceive that we are injured, that something is not right in our body, that we need a greater supply of oxygen, that we need to drink water or eat, or that we are sexually excited
Although it is sometimes separated from interoception, pain perception or nociception It would also be included in the ability to detect changes in body balance.
And not only that: although interoception is generally thought of as something merely physiological, the truth is that it is largely linked to the experience of emotions. For example, it is not easy to determine if we feel disgust if the emotion of disgust is not accompanied by gastric-type sensations. And this is important when it comes to being able to self-manage our emotions and behavior depending on the situation we are experiencing and what it awakens in our body. It is also related to the perception of oneself as one’s own entity.
In order to be able to perceive the stimulation, it is necessary that there be some type of element responsible for detecting it. In other words, there needs to be some type of biological receptor
Interoceptive receptors are found throughout the body, generally in all major organs and blood vessels. They are found in the endoderm. The interoceptive system does not use a single type of receptor, but rather collects information from mechanoreceptors (sensitive to deformation), thermoceptors (which capture temperature), baroreceptors (sensitive to blood pressure) or nociceptors (which capture the rupture of cells and send pain sensations) and reports the state of the organ(s) in question (these receptors may be affected by different stimuli or situations depending on the specific organ we are talking about).
Generally these are receptors that remain silent, unless an alteration occurs that activates them and causes them to react by sending signals. For example, We don’t usually notice that our heart is going faster or slower unless we are nervous or accelerated, or that we lack water unless its lack causes them to generate sensations (which will cause the nervous system to trigger the perception of thirst to compensate.
Body systems in which this sensory function has been studied
The sense of interoception extends to almost the entire set of organs and tissues of the body. However, the role of this sense has been explored more often in some specific body systems.
1. Cardiovascular system
The system that has received the most attention in research. In this sense, Interoceptive information allows us to have cardiac-type sensations such as heart rate or acceleration, or blood pressure levels. This is information that allows us, for example, to realize that we are having a heart attack, or that our pulse is accelerating.
The perception of alterations in this system is based mainly on the action of the heart, the information being sent to somatosensory receptors in the thorax At the brain level, it is speculated that the right hemisphere may be more related to the conscious processing of cardiac information, but the research carried out has not reflected the existence of conclusive data in this regard.
2. Respiratory system
Pulmonary interoception is another of the most studied, also linked to a large number of possible perceived sensations. Stretching and dilation, irritation and volume, pressure and movement are some of the information that is captured. Also we can detect the existence of obstructions
3. Gastrointestinal system
Movement, distention, temperature or even chemoception are some of the sensations linked to interoception of the digestive tract. Although much of the information processed in this system is usually conscious, it has been observed that some small stimulations may not generate conscious perception
Alterations in interoception
Interoception is a very important sense that allows us to adjust our behavior to what is happening internally to our body. However, it does not work correctly for everyone, which can cause different problems.
These alterations can be due to excess or defect: it is possible that there is hypersensitivity that causes the interoceptive receptors to activate with little stimulation or that the receptors do not activate, which would make it very difficult to adjust the behavioral response.
This is what happens with those people with congenital insensitivity to pain with anhidrosis or CIPA, not being able to perceive the suffering that stimulation generates and (usually) temperature. We can also find that interoception is altered in various psychiatric conditions, such as in some hallucinations typical of psychotic episodes or in manic episodes. Finally, the consumption of some drugs and/or intoxication by some toxic element can alter the body’s interoceptive capacity.
