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Eye tracking abnormalities in schizophrenia: evidence for dysfunction in the frontal eye fields
J A Sweeney1, B Luna, N M Srinivasagam
1Department of Psychiatry, University of Pittsburgh School of Medicine, Pennsylvania, USA.
Biological Psychiatry
|November 3, 1998
Summary
Schizophrenia patients show impaired eye movement control, specifically in smooth pursuit initiation and gain, suggesting frontal eye field pathway dysfunction. These deficits persist over time, impacting visual tracking abilities.
Area of Science:
- Neuroscience
- Psychiatry
- Ophthalmology
Background:
- Eye tracking deficits are common in schizophrenia.
- The underlying neurobiological cause of these deficits remains unclear.
Purpose of the Study:
- To investigate the pathophysiology of eye tracking disturbances in schizophrenia.
- To clarify the neurobiological basis of abnormal eye movements in schizophrenia patients.
Main Methods:
- Tested 12 first-episode, treatment-naive schizophrenic patients and 10 healthy controls.
- Utilized foveofugal and foveopetal step-ramp pursuit tasks to assess eye movement control.
Main Results:
- Schizophrenic patients exhibited delayed pursuit initiation and reduced steady-state pursuit gain, especially at slower speeds.
- While primary catch-up saccades were normal, postsaccadic pursuit was significantly impaired in the initial 100 ms after saccades.
Conclusions:
- Posterior temporal cortex motion processing is intact for catch-up saccades but not effectively used for pursuit.
- Impaired pursuit initiation and low gain suggest frontal eye field pathway involvement in schizophrenia's eye tracking abnormalities.