The brain is a complex organic structure that strongly guides our behavior, but it is also the place where our thoughts and emotions live, the search for its biological substrate is essential to understand how cognition works, however, its complexity, combined with methodological difficulties, makes it very difficult to explore the nervous system. One way to better understand how it works is to study neurological disorders.
Normally, damage to the structures of the nervous system has a more or less noticeable effect on our behavior, if we associate these consequences with damaged areas we can locate a variety of functions and processes, although some caution is necessary, since people with neurological diseases . Disorders have special conditions that can distort or contaminate conclusions about them. Examples of this noise can be seen in subjects who have multiple affected areas or who are taking medications with many side effects.
- In this article we will talk about three neurological disorders that.
- In a way.
- Seem incredible and that will help us understand the extent to which each cognitive process is mediated by a biological substrate.
- Vision.
- Visual hemineglygence and divided hemispheres.
Imagine if we have in front of us a person who has recently had an accident, we also know that as a result of this accident he suffered brain damage, then informs us that he sees absolutely nothing, that he has lost it. Vision.
But we see something different. His eyes follow us, and that’s why we keep investigating, when we ask you to take an object, the person approaches and grabs the object as if he were seeing it, not only that, if we insist that you try to guess the numbers shown on a screen, the person will be right with much greater precision than you would expect if he tried to guess the possibility. How is that possible?
After observing the patient’s behavior, the data show that the patient sees what is going on around them, but their speech says they are blind. The answer is no, the problem is that the subject is not able to understand what he sees, consciously processes all visual stimuli, but for lack of attention this data does not go to consciousness.
This is one of the most incredible neurological disorders, because people with neurological disorders are living proof that there is treatment without conscious intervention.
Visual hemineglygence is another of the attentional neurological disorders, as is the case with blind vision, is associated with lesions of the right prefrontal cortex, a key aspect to understand this is that the left prefrontal cortex deals with the attentional processes on the right side of the visual field and, on the other hand, the right prefrontal cortex deals with the attention of the left visual field , so damage to the right cortex will leave the subject without attention in the left visual field.
What is the awareness of this? These patients will only know the right side of their vision, in them we see behaviors such as: eating only with the right half of the plate, forming only half the face and, when drawing objects, drawing only the right side. The most surprising thing about this disorder is that patients are not aware of having problems, their submission shows them a normal and constant life.
In addition, another interesting aspect is that it affects not only the visual field that the eyes receive, but also the imagination. If we ask the person to stand mentally in Milan Cathedral Square and describe the scene, he will only mention the elements on the right. On the other hand, if we then ask you to turn around, having the items listed above on the left, you will no longer be able to name them. Now I would name the elements I hadn’t named before.
Finally, let’s talk about one of the most curious and impactful neurological disorders, the divided hemispheres, in severe cases it is necessary to perform an operation, which consists of removing the callous body, which is the largest connection of the brain between the two hemispheres. This therefore implies a disconnection of cooperation between the left and right hemispheres.
One of the most curious symptoms is left hand syndrome; with him, it seems that the patient’s left hand has a life of its own and that the subject is not able to report his motor behavior, in fact, the area responsible for the voluntary movement of the left hand is in the right hemisphere, while the tongue is on the left.
In this disorder we observe how each hemisphere behaves independently of the subject, there are a variety of patient reports that assure us this, for example, while a patient is reading a book, his left hand moves to close it, because the right hemisphere cannot read and get bored. In another case, a patient tried to touch his spouse with his left hand, while trying to avoid him with his right hand.