Interoception, or the internal sense, is the sense responsible for receiving, processing, and interpreting signals and stimuli that come from within the body to the brain. This sense serves as a vital control system that allows a person to understand the internal physiological state of their body at any given moment.
Interoception includes identifying a wide range of internal bodily sensations, such as: heart rate, breathing, feelings of hunger and fullness, the need to use the restroom, pain, temperature changes (heat or cold in the body), muscle tension, and fatigue.
Variation in interoceptive sensory processing is very common among autistic people and can manifest at two extremes:
Interoceptive Hyposensitivity: Difficulty feeling or identifying body signals in time. A person may not feel hungry, thirsty, cold, or that they need to relieve themselves until the situation reaches an extreme (for example, extreme hunger suddenly leading to weakness or irritability).
Interoceptive Hyper Sensitivity: High and overly intense sensitivity to body signals, where every slight internal change (such as a slight increase in heart rate) is experienced with great intensity and can trigger anxiety or Sensory Overload.
Since bodily sensations are the basis through which the brain also identifies and interprets emotions (for example, a tightening in the stomach signaling fear), variations in interoception are closely linked to phenomena such as Alexithymia (difficulty identifying and naming emotions). When a person struggles to read their body's warning signals in time, they may suddenly find themselves in situations of neurological overload, Meltdown, or Shutdown, without realizing that the burden has been building within them. Current therapeutic and supportive approaches place great emphasis on learning, identifying, and accepting the unique body sensations of the autistic person without judgment.