Our brain has the ability to store information and then, through different stimuli, return to it. For example, we know that something with a trunk and a crown of green leaves is a tree, and no matter how different one is from another, we will always know a tree when we see it.
But those who suffer from agnosia may be able to see the object with trunk and leaves, and may not recognize a tree in it. It is that it is a strange disease that can develop in different ways, but specifically it is a difficulty in recognizing things learned. There are serious cases like these, but also others, much more common, in which it is very difficult for a person to recognize a face even though they have already seen that person on several occasions.
That is, people with agnosia can identify a stimulus, but they cannot associate it with what it means.
Different types of agnosia
In the tree example, the person would suffer from visual agnosia. That is, the person can see normally, since her vision works correctly, but he cannot recognize the object he is seeing.
Visual agnosia has, in turn, different aspects. One is prosopagnosia, which has had a certain degree of knowledge because it was suffered by Brad Pitt. In this case, it is about recognizing all the parts of the face, but not being able to associate it with the person to whom it belongs.
Visual agnosia can also manifest itself in the inability to recognize colors (Chromatic Agnosia), to understand movement (Kinetoagnosia), or to understand the relationship between objects (Simultagnosia).
Although slightly less common than visual agnosia, there are other types of the disease. Auditory agnosia manifests itself primarily in the inability to understand spoken language. Tactile agnosia does not allow sufferers to recognize things by touch.
A particularly rare case of agnosia is body agnosia, which occurs when a person is unable to recognize a part of their body as their own. It usually happens after having a stroke episode.
What are the causes
Agnosia is the result of a brain injury, so it almost always appears at a specific time in life.
This injury may have to do with head trauma from a blow or accident; to a stroke; to dementia or intoxication.
It can also appear with other neurological disorders.
Do you have agnosia or prosopagnosia?
Having a hard time recognizing familiar faces even when you’ve seen someone several times can be embarrassing, but it doesn’t mean you have a disease. However, many people consider themselves simply forgetful when they actually have this disorder.
Identifying agnosia is relatively easy for a doctor, who through different stimulus tests will be able to determine the disease. To realize that you should turn to a professional, you should see if it is difficult for you to recognize simple things.
As we said, this difficulty appears after some specific brain damage, so if you have suffered some type of accident and identify any of the symptoms you should see a doctor immediately.
Although agnosia is not cured, symptoms can be greatly improved with various rehabilitation treatments. For example, in the case of visual agnosia, one can resort to trying to identify objects by their sound (and vice versa in the case of auditory agnosia).