People with schizophrenia see through visual illusions that trick most people
'These illusions can be viewed as a sort of thermometer to measure the severity of brain processes underlying psychosis.' - Steven Silverstein
Diagnosing schizophrenia can be difficult as its symptoms often resemble those of other diseases and conditions, including bipolar illness and severe depression or several neurological disorders.
Mental health professionals currently rely on a series of psychological and life-history evaluations as a way to diagnose patients. But a three-dimensional illusion that tricks most people into seeing close objects in the distance and background objects up close may represent a breakthrough in detecting the illness.
This potentially lifesaving use for visual illusions has emerged from collaboration between a Rutgers vision researcher and a Robert Wood Johnson Medical School clinical psychologist that began almost by chance four years ago.
The so-called reverse perspective illusions that the researchers are testing are not new – they’ve been around for centuries as art and entertainment. In recent years, scientists have used them to pin down how the mind sometimes misinterprets what the eyes see.
But it turns out that people with schizophrenia are not that easily fooled by visual illusions. That’s the key to their potential as a powerful diagnostic tool.
“These illusions can be viewed as a sort of thermometer to measure the severity of brain processes underlying psychosis,” said Steven Silverstein, professor of psychiatry at the Robert Wood Johnson Medical School and director of schizophrenia research at University Behavioral HealthCare. Today there is no simple biological marker or lab test for schizophrenia, he notes.
Silverstein and his Rutgers collaborator, Thomas Papathomas, are rigorously testing the effectiveness of illusions as a way to diagnose and measure the level of psychosis in schizophrenia in clinical environments. They are also working to establish their illusions as reliable, inexpensive and easy-to-use tests – something accessible to smaller clinics and not limited to major teaching hospitals.
Papathomas, a professor in the Department of Biomedical Engineering and director of the university’s Laboratory for Vision Research, is a renowned vision researcher informally regarded as an accomplished illusionist. He educates students and entertains campus visitors with face masks and cityscapes that appear to rotate to the right when someone turns them to the left, and vice-versa, because of the way our minds process perspective, and in these cases, misperceive it.
A year ago, his team scored fourth place in a visual perception contest with an illusion of a sculpture’s head rotating around its torso. Named the “Exorcist Illusion,” after a 1973 horror film where a demon-possessed child’s head spins impossibly around her neck, it later received accolades at a European conference and was showcased in popular science web sites.
“We knew about each other’s work, but we never happened to need to work together,” Papathomas said of Silverstein. The two were attending the same vision science conference in Florida in 2009 and met over dinner to discuss a postdoctoral candidate who had approached both for a job. Neither could offer him a full-time appointment, so the candidate, Brian Keane, proposed a joint arrangement.
“Steve asked me if I’d be willing to co-sponsor Brian,” Papathomas recalled. “We agreed and found work for him that was of mutual interest.” That catalyzed a collaboration later funded by the National Institutes of Health, with a paper soon to be published in the prestigious Journal of Abnormal Psychology. Several more papers have been submitted or are in progress.
“Schizophrenia is a complicated and severe mental illness,” said Silverstein. “Symptoms include hearing voices, seeing visions, delusional thinking and having ideas not shared by people around them.” People with the disease are often unable to work or live independently, and have high rates of substance abuse and suicide.
Diagnosing schizophrenia today is difficult because other physical and mental illnesses can trigger similar symptoms and results on psychological assessments. In addition, many patients are not motivated to engage in tasks or they experience side-effects from medication, making test scores hard to interpret. Illusions can sidestep these problems.
In Papathomas’s “hollow mask” illusion, for instance, a face is painted on the inside of a mask. But when most people look inside the mask, they perceive it as being a conventional face; that is, on the outside of a mask.
“That’s because the mind knows what faces are supposed to look like, and the mind overrides what the eyes actually see,” said Papathomas.
But that connection between sensory information and stored knowledge is somehow disconnected in people with schizophrenia, Silverstein noted. Ironically, that makes people with the illness better able to perceive the hollow mask for what it literally is – the inside of a mask.
If these illusions indeed prove to be specific and accurate measures of schizophrenia, the scientists can think of ways to manage the disease more effectively and develop new therapies. Responses to illusions might help clinicians determine if a healthy person with a family history of schizophrenia is likely to develop it, or if a person previously treated for the disease is at imminent risk of relapse.
“If you could identify someone who is starting to have some changes in the brain, but they haven’t started to hear voices or have paranoid delusions yet, that’s a better time to get them in for sessions and medication,” said Silverstein. “Right now there are no laboratory tests that can say a person is starting to head that way.”
Drug companies working on new medications also need tests for use in early phase drug trials, where they work with smaller numbers of people in shorter periods of time. Papathomas and Silverstein hope to partner with industry to see if their illusions could become part of those laboratory tests.