Eye-Movement Test Accurately Indicates Schizophrenics

Pic: Vitold Muratov (CC)

Pic: Vitold Muratov (CC)

A recent study proposes that we may be able to use current technology to identify schizophrenics without spending the copious resources for a qualified neuropsychologist to diagnose an individual case.  What implications can this have for pilot licensing, holding government office, police recruiting, and generally the overall stigma associated with individuals who are functioning and non-functioning clinical schizophrenics?

A group of scientists from Scotland, Germany, and the USA recruited schizophrenic patients from mental hospitals in Munich, Germany and Aberdeen, Scotland. The researchers confirmed schizophrenia by diagnostic procedures in the DSM-IV as well as case history.  Control group participants were recruited from the area surrounding University of Aberdeen, excluding people with a history of alcohol abuse/dependence, major head trauma involving loss of consciousness for more than 5 minutes, epilepsy or other neurological dysfunction, and first-degree family history of psychosis.

Using infrared eye-tracking technology via the EyeLink I and a 19” video screen, the study tested visual patterns in smooth pursuit of a moving object for 20 seconds, fixation stability on the same stationary object, and free-viewing of photographs including:

“Luminance-balanced natural and man made environments showing information at different spatial scales; everyday objects and food in sparse and cluttered scenes; expressive, neutral, and occluded faces; animals; and unfamiliar computer-generated images (fractal patterns, gray-scale ‘pink noise.'”

The conclusion brought by the research is that schizophrenic individuals clearly lack an ability to perform visual tests the same as control individuals.  Diagnosed schizophrenics cannot accurately pursue an object with a smooth speed and path or concentrate with normal patterns when steadily gazing at the photographs presented.

Not every individual exhibits “normal” or “abnormal” eye movements on every trial, so the study analysis combined multiple performance measures from multiple tests.  A small covariation in fixation stability was caused by advanced age in the test subjects, but aside from that no other consistent covariations were presented by the data. Pharmaceutical regimens had no bearing on the concluding classification.  There was no relationship between probability of classification as “schizophrenic” and the number of chlorpromazine equivalents prescribed, age of onset/duration of illness, or presence or absence of cigarette smoking.

98% of the participants were correctly classified; one schizophrenic patient was misclassified as control and five control subjects were misclassified as borderline.  After a retest at 9 months, the reliability of diagnosis was no different (test (SD = .843) and retest (SD = .804)).  The study purports, “This is a remarkable level of discrimination and well beyond that of other potential trait markers previously reported in schizophrenia.”

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  • Jesse Taylor

    Can someone point me to a “normal” person? I hear all this talk about
    “normal” vs. “abnormal”, but I’ve never met a person who qualifies as
    normal. Any specific examples?

    • Jesse Taylor

      What is “normal” eye movement?

      • Calypso_1

        It has primarily to do with how the eye tracks movement and maintains focal fixation. They are called saccades. These are not consciously controlled and are altered in various brain pathologies.

        • fnordburger

          That doesn’t answer the question. You’re assuming there’s some kind of ideal brain behaviour written down in a manual somewhere, which there isn’t. Nice words, though.

          • Monkey See Monkey Do

            Its not really a question of ideal, its more normal = ordinary. There is unconscious and sunbconsious drives to order the physical world into a three-dimensional ‘map’ corresponding to the scene. I imagine various pathologies have altered mechanisms (eye movement, brain chemistry etc) that can affect the map in different ways. In illnesses its often detrimental to the territory.

          • Calypso_1

            I am assuming nothing. Just like there is proper range of movement for any of the joints, outside of that range of movement the joint is damaged. There are ways that the physiology of neurons are supposed to operate. Damage the neurons and they do not operate they same. As I said there are other pathologies where these effects are evident, notably epilepsy. Schizophrenics have demonstrable pathology. This is just a manifestation of it.

          • Jesse Taylor

            Who defines what a “proper” range of motion is? Who wrote the guidelines for how neurons are “supposed” to operate?

          • Calypso_1

            For both:
            nature
            when tissue is damaged it is not operating properly.

          • kowalityjesus

            Here is a screencapture, which I think couldn’t be displayed in the article for copyright reasons.

          • Calypso_1

            It should be noted that this inability to maintain fixation results in a high incidence of autokinetic illusions which are often the cause of misattributing stationary lights as UFO’s.

          • kowalityjesus

            that is a possible correlative, but I think the symptom only accounts for certain cases, especially since if I stare at a star long enough it will appear to move, and I may be crazy, but I am not clinically schizophrenic.

            There is a classic account of this type of mistaken UFO observation at 9:16 in this video. https://www.youtube.com/watch?v=Qt1WVeyMqdo also the man’s advanced age may have been a contributing factor as cited in the study.

          • Calypso_1

            Everyone experiences the autokinetic effect. It’s a matter of degree and if it induces other perceptual illusions.

      • kowalityjesus

        I you click on the link to the study at the beginning of the article it will show to diagrams which will explain that.

  • BuzzCoastin

    Schizophrenia is a mental disorder characterized by a breakdown of thought processes and by impaired emotional responses.

    Common symptoms include delusions, such as paranoid beliefs; hallucinations; disorganized thinking; and negative symptoms, such as blunted affect and avolition.

    Hmmmmmmm, eye movement huh?

    • Calypso_1

      Are you expressing confusion?

      • BuzzCoastin

        no
        that’s a projection of your mind
        sometimes called an hallucination
        a symptom of disorganized thinking
        hmmmmmmmmmm

        • Calypso_1

          No
          it was a question

          • BuzzCoastin

            I saw your eyes move

  • Tomato

    “…without spending the copious resources for a qualified neuropsychologist to diagnose an individual case. ” What is this? “The express diagnose for a serious mental ilness?” The patients should have a diagnose consisted from various different methods , don’t forget that they used to misclassify several different mental diseases and therefore the patients would get mistreated.

    • kowalityjesus

      Wow, you should take an English course. This is to assess a patient upon admission to a hospital or whatever, to see whether they are ‘clinically’ crazy. The consistency between the trait marker and diagnosis is unprecedented and uncanny, but that’s what the reputable study claims.

  • AManCalledDa-da

    Source, please.

    • Calypso_1

      It’s hyperlinked in the first sentence.

      • echar

        The links works, but a person is unable to see the study due to some error.

        • Calypso_1

          works for me

          • echar

            Ahhh… I allowed myself to be distracted by the error, and missed the download hyperlink.

            PermanentRedirectThe bucket you are attempting to access must be addressed using the specified endpoint. Please send all future requests to this endpoint.

            Expectations!

  • DrDavidKelly

    Is this to be an empathy test? Capillary dilation of the so-called blush
    response? Fluctuation of the pupil. Involuntary dilation of the iris…

    • Dave Kool

      HA! About 2 paragraphs in my first thought was “Holy crap, they finally made a Voight-Kampff machine!”

      Well played sir, well played.

  • echar

    Sadly, their lust for power and lack of conscience offer them a leg up.

  • Calypso_1

    No, not assuming that either. But you are assuming that a pathology is merely a variance.

    • codedp

      I never said I wasn’t assuming– :)

  • DrDavidKelly

    Thanks Katia. Yes it is a Blade Runner quote. Great movie and probably my favourite movie score of all time. Oh and you’re awesome for saying that I am awesome.

  • kowalityjesus

    Wow, that is fascinating! I didn’t realize there was such an apparent correlation between infection and behavior change. Also, I thought t. gondii was a parasite, hmmm. Unfortunately, the link is dead, so I didn’t get any further information. Did you want to submit this as an article?

  • ManwithnoCountry

    Ugh. Technology is making personhood increasingly violable. The Millenials I’ve know have serious respect for privacy; the only question is whether we’ll have to experience abject no-privacy before everyone realizes that this shit ain’t cool.

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