title: Specific motion processing pathway deficit during eye tracking in schizophrenia: a performance-matched functional magnetic resonance imaging study.
abstract: BACKGROUND
  The neural mechanisms underlying smooth pursuit eye movement (SPEM) abnormalities in schizophrenia are not well understood. Previous evidence suggests that a deficit in the processing of internal representations of object motion (extraretinal motion) contributes to SPEM deficits in patients. Functional magnetic resonance imaging (fMRI) activation was compared between patients and control subjects to determine whether schizophrenia patients exhibit abnormal cerebral activation in regions associated with extraretinal motion processing during SPEM.
  
  
  METHODS
  Patients and control subjects were selected based on matched performance in the closed-loop gain. Despite similar performance on closed-loop pursuit gain, patients showed consistent deficits in extraretinal motion based on predictive pursuit. In the magnet, subjects were tested using a traditional smooth-pursuit task that elicits closed-loop response.
  
  
  RESULTS
  Patients had reduced pursuit-related activation in several known extraretinal motion processing areas including frontal and supplemental eye fields, medial superior temporal cortex, and anterior cingulate. Patients also showed increased activation in medial occipitotemporal cortex.
  
  
  CONCLUSIONS
  These results provide functional anatomic evidence supporting reduced function in the extraretinal motion processing pathway in schizophrenia. Increased activation in medial occipitotemporal cortex suggests an increased dependence on immediate retinal motion information, which may be used to compensate for reduced extraretinal signaling during sustained visual tracking.
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore 21228, USA. ehong@mprc.umaryland.edu
authors.forename: L Elliot
authors.initials: LE
authors.lastname: Hong
authors.forename: Malle
authors.initials: M
authors.lastname: Tagamets
authors.forename: Matthew
authors.initials: M
authors.lastname: Avila
authors.forename: Ikwunga
authors.initials: I
authors.lastname: Wonodi
authors.forename: Henry
authors.initials: H
authors.lastname: Holcomb
authors.forename: Gunvant K
authors.initials: GK
authors.lastname: Thaker
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping; D016022:Case-Control Studies; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D015835:Ocular Motility Disorders / Q000209:etiology*; D010100:Oxygen / Q000097:blood; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D014794:Visual Fields / Q000502:physiology
chemical_list: D010100:Oxygen