Behavioral and brain imaging studies of saccadic performance in schizophrenia

Data are reviewed from a series of saccadic studies demonstrating that schi zophrenia subjects have normal performance on some types, and abnormal perf ormance on other types, of tasks. Normal refixation saccade characteristics and BOLD signal change among schizophrenia subjects suggest that basic sac cade generating circuitry is functionally intact among these subjects. Schi zophrenia patients and their relatives, however, demonstrate difficulty wit h saccadic inhibition, a function ostensibly mediated by DLPFC circuitry. W e review additional evidence for saccadic inhibition being associated with prefrontal circuitry provided by EEG and fMRI data. Minimum norm analysis o f EEG data suggests that dipolar activity preceding correct antisaccades oc curred preferentially in prefrontal cortex. Furthermore, there is an indica tion from the fMRI data that prefrontal activity may be increased in normal , but not in schizophrenia, subjects during antisaccade tasks. These data s uggest that a research program relying on multiple functional imaging techn ologies may be helpful for furthering our understanding of schizophrenia's essential neuropathology. (C) 2001 Elsevier Science B.V. All rights reserve d.