article re schizophrenia - those blind from birth do not develop it

[Amw66]

interesting article from my weird and wonderful MSN feed today

MSN

"In 1950, two researchers noticed something that didn’t quite add up. Hector Chevigny, a writer who had lost his sight in adulthood, and psychologist Sydell Braverman were studying the psychological lives of blind people when they stumbled upon an intriguing pattern: schizophrenia, a serious mental illness affecting people across virtually every known society, appeared to be entirely absent in people who had been blind from birth"

"Research is now looking at drugs that act on glutamate, a brain chemical involved in learning and communication between nerve cells. Glutamate systems are particularly active in the visual cortex and in circuits that help the brain filter out what’s important from what can be ignored. These aren’t treatments based on blindness itself, but on what congenital blindness reveals about how a stable, well-organised brain develops."

 

[Jonathan Edwards]

This is a fascinating observation if true. I can think of a way it might make sense but to explain I would need more time.

 

[Jonathan Edwards]

I dont think this would be an issue oof neurotransmitters. I think it may be that sighted people develop a sense of self and world in a visual signal matrix with other signals relegated to a "thin" experiential form. Co-ordinating signals evolves over infant years. Schizophrenia is a condition in which co-ordination of mental processes breaks down. Maybe if you grow up without a visual matrix a potential instability does not arise. I think this will be a problem of connection architecture rather than chemicals.

 

[forestglip]

Note that there are those who say it may be an issue of statistical power:

Is Early Blindness Protective of Psychosis or Are We Turning a Blind Eye to the Lack of Statistical Power? (2020, Schizophrenia Bulletin)

the observed lack of case reports and register-based concurrences of the 2 disorders could be due to pure chance, low power, and ascertainment bias. Indeed, demonstrating a negative association between two rare conditions is extremely challenging and requires large sample sizes

As all other published results are also inconclusive,1–3 we strongly advice against drawing any conclusions on the issue based on the available evidence. Furthermore, theories on how blindness is protective of psychosis4 are premature and should, if proposed, clearly state that there is currently no evidence that it actually is protective.

 

[Amw66]

I dont think this would be an issue oof neurotransmitters. I think it may be that sighted people develop a sense of self and world in a visual signal matrix with other signals relegated to a "thin" experiential form. Co-ordinating signals evolves over infant years. Schizophrenia is a condition in which co-ordination of mental processes breaks down. Maybe if you grow up without a visual matrix a potential instability does not arise. I think this will be a problem of connection architecture rather than chemicals.

seems so - from the article

"Scientists now understand schizophrenia as, at least in part, a disorder of prediction. The brain is constantly generating expectations about its surroundings and checking them against signals from the senses. In schizophrenia, this process appears to go wrong. Weak or random signals are given too much weight. Coincidences feel significant. Thoughts can seem to come from somewhere outside oneself. The boundary between imagination and reality begins to blur.

A question of prediction​

Vision plays a powerful role in shaping this system, particularly in early life. The visual cortex is one of the brain’s largest and most richly connected regions, involved not just in sight but in learning, attention and emotion. When it receives no input from birth, the brain develops differently. Brain imaging studies show that in people with congenital cortical blindness, this area is often repurposed for tasks such as language, memory and reasoning."