Doesn’t that sound paradoxical? It is. But there are many neuronal disorders. It is hard to explain. They are blind people and if you ask them if they can see they will say no. They don’t lie, but they have a different kind of vision. It’s not about paranormal forces. It is the strange disturbance of “blind vision”.
A team of psychologists carried out an experiment. The volunteer was completely blind. They led him to a hallway full of obstacles. They took his stick away and asked him to walk down the corridor. He could move through the obstacles without stumbling once. How could it happen?
This man suffered from the strange “blind vision” disorder. Those who suffer from it deny being aware of the objects in front of them. But the facts show that they have to see them somehow.
In another case, a blind-sighted man was placed in front of a screen. They asked him to say what pictures were there. His hit rate was 90%.
Road interrupted
Blind vision is caused by damage to an area of the brain called the primary visual cortex. Damage in this area can lead to blindness, sometimes totally, sometimes partially. How does blind vision work then? The eyes receive the light and convert it into information, which is then transmitted to the brain.
This information travels to the brain in a number of ways and ends in the primary visual cortex. In the blind, this area is damaged and cannot process information appropriately. It never reaches consciousness.
However, this information continues to be processed by other intact areas of the visual system.
Blind vision has caused a lot of controversy. Some psychologists argue that people with this problem may know what they are up to. Although it is vague and difficult to describe.
However, determining whether someone knows something special is a complicated and very delicate task. There is no “test” to recognize consciousness. We can certainly ask. However, interpreting what people say about their own experiences can be a complex task.
Some people with blind eyesight report “visual pinpricks” or “dark shadows”. Could some awareness remain?
If you look at what the brain can do without consciousness, interesting questions arise. Are blind people aware of what lies ahead? What is your conscience really like? How is it different from the types of consciousness that we are most familiar with? And exactly where does consciousness begin and end in the brain?
The strange disturbance of “blind vision” reveals the blurred boundaries at the limits of vision and consciousness. In cases like blind vision, it is less and less clear whether our normal concepts like “perception”, “consciousness” and “seeing” are up to the task of adequately describing and explaining what really happens.
There is no doubt that our knowledge of the brain and its functions still has a long way to go. Isn’t that exciting?
