Specific motion processing pathway deficit during eye tracking in schizophrenia: a performance-matched functional magnetic resonance imaging study.
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.
Hong
L Elliot
LE
Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore 21228, USA. ehong@mprc.umaryland.edu
Tagamets
Malle
M
Avila
Matthew
M
Wonodi
Ikwunga
I
Holcomb
Henry
H
Thaker
Gunvant K
GK
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
D010100:Oxygen