The Bizarre Link Between Blindness and Schizophrenia

[Music] if you start reading pop psychology listicles you might come across this statement supposedly no one who is born blind has ever been diagnosed with schizophrenia we saw this so-called fact - and it seemed so bizarre that we almost immediately dismissed it after all schizophrenia is a mental illness with symptoms including delusions disordered thinking and hallucinations how is that closely related to being blind well surprisingly there is some truth behind this idea in the nearly 70 years they've been looking and despite the fact that it should happen statistically researchers have found no known cases of someone with a certain kind of blindness also being diagnosed with schizophrenia it sounds unlikely but some evidence suggests these conditions are more closely related than you might think in fact some scientists think this kind of blindness may even prevent people from developing schizophrenia in the first place first it's worth noting that this research has only looked at small limited sample sizes and is only based on correlations that doesn't mean these studies aren't useful but it does mean it's too early to say anything for sure especially since we still don't know what causes schizophrenia that being said some researchers have made pretty interesting observations here their work is specifically focused on congenital or early cortical blindness which we'll call CC B for short this is a condition someone has at birth or develops in infancy and it's blindness caused by a dysfunction in the brains occipital visual cortex so if someone became blind as an adult or was born blind because of something about their eyes these studies don't apply at first glance it might not seem like this condition has anything to do with schizophrenia but once you look at how the brain might cause schizophrenia symptoms the possible connection becomes a lot more clear take visual hallucinations for example they're relatively common in people with schizophrenia and some evidence suggests they could happen when someone has trouble integrating information from their senses especially their sense of sight the idea is that the brain would have trouble getting the visual information it receives to line up with what it's getting from the other senses and because of that or in an effort to compensate it could end up producing hallucinations of course if someone had never gotten any visual input like say if they had CCB this couldn't happen there would be nothing to overwhelm the brain so this process couldn't be triggered this isn't the only connection scientists have notice though they've also seen a similar relationship with auditory symptoms people with schizophrenia tend to score lower on measures of auditory processing and they frequently report having auditory hallucinations to things that are likely related to the brain's auditory cortex it's too early to say that these cortex conditions cause those symptoms but some experiments have found a correlation between the two in one published in 2017 for example participants with schizophrenia who had experienced auditory hallucinations tended to have thinner auditory cortex than those who hadn't so where does Cece be coming well many folks with this kind of blindness have spent their lives relying more on their sense of hearing so they tend to have a greater auditory perception than average and brain scans have revealed structural changes that reflect that most notably their auditory cortex is have likely expanded so even if someone with CCB was born with a thinner auditory cortex or was at risk of developing one having to rely on their hearing could have strengthened that brain region and that could lower their risk for developing auditory hallucinations relationships like this one have been observed on a larger more brain wide scale although the consequences there are still a bit fuzzy in any case though this research is all based on correlation which means we can't conclusively say CCB prevents schizophrenia but one thing we can say is that these studies are still significant they're super interesting on their own and on a larger scale they can teach us more about how conditions like schizophrenia affect the brain and how we could treat them based on this kind of research scientists have suggested that people at high risk for schizophrenia might benefit from some kind of cognitive training at a young age training that works on things like sensory or perceptual skills we don't know if that would be able to prevent the condition from happening but it would hopefully improve someone's quality of life ultimately this is another example of how our brains are full of surprises and how seemingly unrelated systems are connected and by studying relationships like this there's a lot we can learn if you want to learn more about schizophrenia and how it might be different than what you've heard you can watch our episode about it after this and as always thanks for watching this episode of scishow Sykes [Music]

Channel: SciShow Psych

Views: 49,291

Keywords: SciShow, science, Hank, Green, education, learn, brain, psychology, The Bizarre Link Between Blindness and Schizophrenia, Brit, Garner, blind, schizophrenia, delusions, disordered thinking, hallucinations, mental disorder, congenital or early cortical blindness, CCB, occipital visual cortex, auditory symptoms, symptoms, eyes, vision, sense

Id: xdSh3Ycw1fw

Length: 4min 27sec (267 seconds)

Published: Thu Oct 24 2019