Functional MRI of visual exproration and eye movements in schizophrenia

Abstract

[Introduction] It has been suggested that abnormal exploratory eye movements are a behavioral marker for schizophrenia. We measured the brain activation maps using fMRI of healthy and schizophrenic subjects to explain the neural networks dysfunction in schizophrenia during exploratory eye movement task. [Subjects & Methods] Twelve healthy and thirteen schizophrenic subjects participated in this study. The subjects were asked to remember a series of presented figure of Benton Visual Retention Test and to compare subsequent figure. The subjects were required to indicate whether the two figures were the same or not by pushing a button. [Results & Conclusion] The result of reaction time and correct answer in schizophrenic patients to be compared with healthy subjects are not significant. Schizophrenic patients showed the more widely activations than normal subjects in the cortical regions including the parietal, frontal and supplementary eye fields. On the other hand, schizophrenic subjects showed reduced activity in the lentiform nucleus and the thalamus compared to healthy subjects. Our results indicate that the dysfunction of striato-thalamic network is intrinsic in schizophrenia and induced fronto-parietal cortical dysfunction. [Jpn J Physiol 54 Suppl:S191 (2004)]