Taste, feel indignation at something that seems unfair, regulate our blood pressure when we are running or even feel sexual arousal. Many of these experiences have an important relationship with an area of our brain similar to an island or "insula" (in Latin), an interesting brain region that until very recently has been a great unknown and of which we will talk today.
The insula is an important region of the brain that is involved in multiple functions: it seems to have a great relationship with basic emotions such as love, sadness, hatred or happiness. In addition, it has a very important role in terms of regulating the body to achieve homeostasis and its involvement in the perception of consciousness of ourselves and subjective emotional experiences, is another of its most prominent roles.
The insula is located in the depth of the lateral sulcus, the fissure that separates the parietal and frontal lobe and the temporal and parietal lobe in its upper part. There is an insula in each cerebral hemisphere that is covered by these overlapping cortical regions, so the insula can only be visualized from certain slices in which the depth of the brain is observed. Its structure is divided into two parts:
The insula works as an integrating center for different systems such as the autonomous one or the audiovisual system. This brain region has a strong implication in emotional processes, self-awareness and even language, taste and olfactory processes. Next, we explain some of its relevant functions.
The insula is closely related to the limbic system, key in emotional processes. According to the neuroscientist Antonio Damasio, this brain region makes us aware of the bodily sensations that we have before a specific event, that is, it makes us know how to interpret what we understand by feelings, according to our bodily states.
It is stated that the insula is involved in emotional processes as important as maternal love, romantic love, fear, sadness, happiness, empathy or sexual arousal, among others..
There are functional magnetic resonance imaging results that indicate that the right anterior insula is activated when people establish awareness of their own body, such as by listening to their heartbeat. In addition, it is involved in the control of blood pressure, particularly during exercise, the measurement of body temperature, abdominal and bladder sensations, among others.
Furthermore, the insula plays a great role in the ability to feel and measure the degree of pain and is even related to the feeling of empathy for the pain of others.
In addition to these perceptions, the insula is also involved in perceptual processes related to laughter or crying, compassion or passive listening to music..
It seems that the insula, specifically the anterior area, is highly involved in the processing of certain social emotions. Their activity is related to sensations such as empathy and even orgasm, as well as disgust at injustices or at the physical appearance and smell of other people.
Homeostasis is the tendency of organisms to balance and stability, carrying out the necessary compensations to face the changes that may endanger this stability. It seems that the insula has a very important role in achieving this homeostatic state, managing to control the autonomic functions of the nervous system and guaranteeing the basic functioning of the organism..
Some neuroscientists attribute to the insula a role of “central command”, a kind of passive director that maintains the basic movements for survival such as gastric motility, the act of swallowing when eating, the movement of the hands and eyes or even the regulation of heart rate during exercise.
Given its high functionality, damage or changes in this brain area can cause different consequences. Among some of these consequences is progressive expressive aphasia, a deterioration of communication and linguistic ability in which people cannot communicate fluently. This is due to an atrophy of the anterior insular cortex.
Other studies show that the functioning of the insula is related to anxiety disorders, as well as anorexia nervosa; Furthermore, damage in this region can lead a person to apathy, lack of libido and the inability to differentiate fresh food from spoiled food..
In addition, the insula has strong implications in drug addiction, since different studies with images show how it is activated when the signs of the context make a drug dependent person feel the desire to use again. These studies have focused on different drugs such as heroin, cocaine or nicotine, always giving the same results. In fact, years ago it was shown that small lesions on the insula made smokers not feel any type of withdrawal syndrome when they quit smoking.
Thanks to neuroscience, advances in this matter are increasing and brain regions such as the insula that until a few years ago were great unknown, begin to show their many and important functions and implications, some still to be discovered in that mysterious unknown that is even the human brain.