The insula is a part of the brain below the lateral sulcus. The area is involved in many different functions, such as emotions and pain. It is also involved in addiction.
The function of the insula is not yet entirely clear. It is probably involved in combining sensory information with emotions. It is also needed for pain and basic emotions such as aversion and fear.
Furthermore, this area is needed to become aware of certain body states, such as how fast your heart is beating. It is also used to regulate blood pressure during exercise, or to sense the temperature of your surroundings. If you have goose bumps because it is cold, your insula is involved.
This area is a part of the brain, on the inside of both the left and right hemispheres. This brain area lies below the lateral sulcus, which separates the temporal lobe from the frontal lobe. Input to the insula comes from the thalamus and the amygdala, and most output neurons also project to the amygdala.
Several studies have shown that this area is involved in addiction. The insula becomes active when the addicted person comes to a location where they are reminded of the drugs they are addicted to. When the insula of addicts is damaged, their addiction often disappears on its own.
Different forms of aphasia seem to occur after damage to this area. It concerns patients who can still understand easy words, but cannot communicate fluently. There also seems to be a role for the insula in anxiety and emotion-related disorders.
Author: Myrthe Princen (translated by Thomas von Rein)
Image: Marcel Loeffen