Functional anatomy of pursuit eye movements in humans as revealed by fMRI

We have investigated the functional anatomy of pursuit eye movements in hum ans with functional magnetic imaging. The performance of pursuit eye moveme nts induced activations in the cortical eye fields also activated during th e execution of visually guided saccadic eye movements, namely in the precen tral cortex [frontal eye field (FEF)], the medial superior frontal cortex ( supplementary eye field), the intraparietal cortex (parietal eye field), an d the precuneus, and at the junction of occipital and temporal cortex (MT/M ST) cortex. Pursuit-related areas could be distinguished from saccade-relat ed areas both in terms of spatial extent and location. Pursuit-related area s were smaller than their saccade-related counterparts, three of eight sign ificantly so. The pursuit-related FEF was usually inferior to saccade-relat ed FEF. Other pursuit-related areas were consistently posterior to their sa ccade-related counterparts. The current findings provide the first function al imaging evidence for a distinction between two parallel cortical systems that subserve pursuit and saccadic eye movements in humans.