A camera, when it’s recording, captures images. But behind that camera there is always a filmmaking team that pays attention and gives importance to the information that has been captured. It elaborates the information, manipulates it, selects it, understands it. It processes it and then shows the result of that processing to an audience that will store that information, and use it later.

Our brain works the same way . We pick up stimuli, receive information from the outside constantly through our eyes and, just like a performance team, it is processed by our brain, and stored, for use in other moments of our day-to-day life.

But what would happen if that camera lens captured images for a while, but then all the information it had captured went unnoticed and just stood there, useless, useless? This is what happens to people who have an attention disorder called hemineglect or spatial neglect.

What is heminegligence?

Hemineglectomy is a disorder that appears as a result of acquired brain damage (e.g., a brain tumor, ischemia or hemorrhage) in the right posterior parietal lobe, primarily. Precisely because it is in the right hemisphere and because the pathways that go up to the brain are contralateral (they cross each other, going from one side to the other), everything that is captured by the left eye is what is then not processed.

The key to this disorder is that the left part of what is in the focus of attention is not processed , it is not paid attention to.

People who suffer from this disorder experience some situations in their day-to-day life such as the following: they make up only the left side of their face (since the right side of the face that is reflected in the mirror is captured by the left eye), at mealtime they only eat the right side of the plate and they must place everything on this side. When they try to read, they fragment the phrases and words, so it doesn’t make any sense what they read and they have to make it up. They also have trouble writing, as they do not handle spaces well. In addition, this disorder also affects the extremities on the left side, since they do not see them and forget to use them.

How is it different from blindness?

The difference between blindness and heminegligence is that a person with blindness can learn to locate objects in a 360 degree space , with difficulty, of course, but achieving it. This is due, in part, to the fact that the person knows that there is “something” in that space and is aware that, although he or she does not see the objects that are there, in the end he or she manages to achieve a small normality in his or her life despite the limitations. On the other hand, for a person with heminegligence his space is only 180 degrees, because the other 180 for him are not there. People with this disorder have anosognosia (lack of awareness of illness).

As a result, it is possible to think that, sometimes, it is more important that “realization equipment” we have in our brain than the lens that captures images, because in the future we may be able to change that lens for another one if it is damaged. But… will we ever be able to change a damaged cognitive function for one that is functional?

Currently there are various techniques to rehabilitate people who suffer from this pathology. The aim of such rehabilitation is not to cure hemineglect, as this is a chronic disorder. However, work is being done to teach people who suffer from the disorder how to live with it and have a better quality of life. Some of the most effective techniques are the use of prisms, (placing these next to the right eye so that the person can see what is on their left by looking in the mirror) and cognitive re-education (teaching the patient to turn their head to the left enough to be able to perceive their entire visual field with their right eye).

Author: Maria Vega Sanz