Eye-movement representation in the frontal lobe of rhesus monkeys

We systematically explored the frontal eye field (FEF), the supplementary eye field (SEF), and nearby regions of the frontal cortex to establish the limits of these or possible adjacent eye-movement fields in macaque monkeys. We found a medio-laterally oriented band of saccadic eye-movement sites that extended from the inferior limb of the arcuate sulcus onto the medial surface of the hemisphere and into the dorsal bank of the cingulate sulcus. Two parts of this region may be outside previously described eye-movement areas. We conclude that eye movements are more broadly represented in the frontal lobes than previously described: either the SEF extends into the dorsal bank of the cingulate sulcus and laterally to the arcuate sulcus, or there are more than two frontal eye-movement fields.