Usually, we think of a person diagnosed with schizophrenia as a person who sees the world less accurately than we do. But there are illusions that so-called “normal” people are more vulnerable to than are people diagnosed with schizophrenia……
You can check out one of those (a rotating mask) for yourself here. (They say “normal” people will see the illusion of a face looking at them even when they know it is really the inverse side of the mask and they are trying to see it that way. But when I first looked at it, I didn’t see the illusion – I saw just the inverse mask when that side faced me! But then I looked away after a few rotations, and when I glanced back I saw the illusionary face, and since then it has become more difficult for me to see anything but the illusionary face. Everyone else I showed this too by the way saw the illusionary face right away, except for one of my brothers – something genetic there?)
This effect is allegedly produced because “normal” people engage in “top down” processing, which follows rules of expectations such as “noses are always pointed towards me, never inversed” and so they come up with the wrong result in the case of the hollow mask. The researchers propose that the brains of the people diagnosed with schizophrenia are incapable of this top down processing, but another possible explanation is that they are more likely to be in a possibly temporary mode or mental state where top down processing is switched off, which allows them to look at aspects of the world which defy our assumptions. “Bottom up” processing for example can be helpful in creativity, putting the world together in new ways.
Another possible explanation might follow from the observed result that people who are drunk, or high on pot, were also less likely to see the illusion. The researchers didn’t mention it, but it seems likely that all their test subjects diagnosed with schizophrenia were on neuroleptics. These drugs might function just like alcohol or pot, resulting in a drugged state were the illusion is less likely to be seen.