There are quite a handful of theories as to why , from the neuroplasticity of the blind brain to how vision plays an important role in building our model of the world (and what happens when that process goes wrong).
The thing is, it happens : blind people are mysteriously protected from schizophrenia , and possible explanations could help us better understand the condition.
Vision and model of the world
A large body of scientific literature suggests that congenital blindness can protect a person from schizophrenia. This is especially surprising, since congenital blindness is often the result of infections, brain trauma, or genetic mutations, all factors that are independently associated with an increased risk of psychotic disorders.
And everything becomes even stranger when we consider that vision loss in other periods of life is associated with higher risks of schizophrenia and psychotic symptoms. Even in healthy people, blocking vision for a few days can lead to hallucinations . In 2004, for example, 13 healthy people were blindfolded for 96 hours , and 10 of them reported having visual hallucinations between their first and second day in the dark.
Pollak and Phil Corlett, an associate professor of psychiatry and psychology at Yale University, have a theory about why all this happens, which they published late last year in the Schizophrenia Bulletin . It is based on the hypothesis that one of the most important jobs of our brain is making predictions about the world. It is based on the hypothesis that one of the most important jobs of our brain is making predictions about the world .
This view of the brain holds that instead of perceiving the world around us in real time, our brains create a model of what exists, predict and simulate what we experience, and then compare our predictions with what is actually happening , using any mistakes to update or change the model in our minds.
This is where vision comes in. Vision gives us a lot of information about the world around us, and it is an important sense that helps link other sensory signals, such as sound and touch.
When people have problems with their vision, the brain has to make more predictions to explain them. On the other hand, if you couldn’t see anything, you wouldn’t construct those false representations of the world around you. A person who was born blind does not have the visual inputs to help shape his model of the world.
They have to build it with their other senses, a model of the world that could be more stable. What would mitigate the tendency to hallucinations, delusions and strange behavior of people with schizophrenia .