Editing Optical illusion (section)

=== Illusions and schizophrenia ===
[[File:Perception-Action Cycle.png|thumb|Top-down processing involves using action plans to make perceptual interpretations and vice versa. (This is impaired in schizophrenia.)]]
[[Schizophrenia]], a mental disorder often marked by [[hallucination]]s, also decreases a person's ability to perceive high-order optical illusions.<ref name=":22"/> This is because schizophrenia impairs one's capacity to perform [[Top-down and bottom-up design|top-down]] processing and a higher-level integration of visual information beyond the primary visual cortex, [[Primary visual cortex|V1]].<ref name=":22"/> Understanding how this specifically occurs in the brain may help in understanding how visual [[distortion]]s, beyond imaginary [[hallucination]]s, affect schizophrenic patients.<ref name=":22"/> Additionally, evaluating the differences between how schizophrenic patients and unaffected individuals see illusions may enable researchers to better identify where specific illusions are processed in the [[Visual system|visual]] streams.<ref name=":22"/>
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File:Dualing Illusions.svg|thumb|An example of the [[peripheral drift illusion]]: alternating lines appear to be moving horizontally left or right.
	
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[[File:Bjorn Borg Hollow Face.jpg|thumb|An example of the [[Hollow-Face illusion|hollow face illusion]] which makes concave masks appear to be jutting out (or convex)]]
[[File:MotionBlindness.gif|thumb|An example of [[Motion-induced blindness|motion induced blindness]]: while fixating on the flashing dot, the stationary dots may disappear due to the brain prioritizing motion information.]]
One study on schizophrenic patients found that they were extremely unlikely to be fooled by a three dimensional optical illusion, the [[Hollow-Face illusion|hollow face illusion]], unlike non-affected volunteers.<ref name=":3">{{Cite journal|last1=Dima|first1=Danai|last2=Roiser|first2=Jonathan P.|last3=Dietrich|first3=Detlef E.|last4=Bonnemann|first4=Catharina|last5=Lanfermann|first5=Heinrich|last6=Emrich|first6=Hinderk M.|last7=Dillo|first7=Wolfgang|date=2009-07-15|title=Understanding why patients with schizophrenia do not perceive the hollow-mask illusion using dynamic causal modelling|url=http://www.sciencedirect.com/science/article/pii/S105381190900278X|journal=NeuroImage|language=en|volume=46|issue=4|pages=1180–1186|doi=10.1016/j.neuroimage.2009.03.033|pmid=19327402|s2cid=10008080|issn=1053-8119}}</ref> Based on [[Functional magnetic resonance imaging|fMRI]] data, researchers concluded that this resulted from a disconnection between their systems for [[Top-down and bottom-up design|bottom-up]] processing of visual cues and top-down interpretations of those cues in the [[Parietal lobe|parietal cortex]].<ref name=":3" /> In another study on the [[motion-induced blindness]] (MIB) illusion (pictured right), schizophrenic patients continued to perceive stationary visual targets even when observing distracting motion stimuli, unlike non schizophrenic [[Controlling for a variable|controls]], who experienced motion induced blindness.<ref name=":4">{{Cite journal|last1=Tschacher|author1-link=Wolfgang Tschacher|first1=Wolfgang|last2=Schuler|first2=Daniela|last3=Junghan|first3=Ulrich|date=2006-01-31|title=Reduced perception of the motion-induced blindness illusion in schizophrenia|url=http://www.sciencedirect.com/science/article/pii/S0920996405003701|journal=Schizophrenia Research|language=en|volume=81|issue=2|pages=261–267|doi=10.1016/j.schres.2005.08.012|pmid=16243490|s2cid=10752733|issn=0920-9964}}</ref> The schizophrenic test subjects demonstrated impaired cognitive organization, meaning they were less able to coordinate their processing of [[Motion perception|motion cues]] and stationary image cues.<ref name=":4" />