Functional neuroanatomy of smooth pursuit and predictive saccades.

We used PET to study differences in cerebral blood flow (CBF) in smooth pursuit, predictive saccades and fixation. Eye movements were monitored in the scanner. Compared with fixation, pursuit and predictive saccades activated a network of highly similar areas, including frontal eye fields, supplementary eye fields, V5 and medial cuneus. Our findings are consistent with non-human primate studies that suggest that pursuit and saccades are controlled by similar and adjacent neural areas. Pursuit was associated with greater activation of caudate than saccades, suggesting a role for basal ganglia in pursuit that is consistent with studies of neurological populations. Saccades were associated with greater activation of cerebellum and frontal eye fields. A frontal-cerebellar loop may be important in coordinating the preparation and timing of saccades in predictive tracking.