The smooth pursuit pathways in the Rhesus monkey. (a) Lateral view of the left hemisphere with areas involved in motion processing and smooth pursuit preparation. FEF, frontal eye field; MT, middle temporal area; MST, medial superior temporal area; PEF, parietal eye fields; OMNs: oculomotor motoneurons; SEF, dorsomedial frontal cortex; V1: primary visual area; PON, pontine nuclei; VPF, flocculus and ventral paraflocculus; Verm, oculomotor vermis; VN, vestibular nuclei; NPH, nucleus prepositus hypoglossi. Adapted from [12]. For clarity, connections of the PEF with FEF and SEF are not shown and are not essential for the argument presented in this paper. Neurons in the vermis could project to OMNs through the caudal fastigial nucleus. These projections are not shown for the sake of clarity. (b) Simplified schematic diagram of the flow of neural signals in pursuit areas from the visual cortex to premotor neurons. Cb, cerebellum. The role of the shaded areas will be further discussed in this paper.