The properties of convergence eye movements evoked from the rostral and caudal lateral suprasylvian cortex in the cat.

Abstract

Convergence eye movements were evoked in the lateral suprasylvian cortex (LS cortex) in the cat. Three effective regions were found: the rostral and caudal parts of the postero-medial LS cortex (the PMLS) and the rostral part of the postero-lateral LS cortex (the PLLS). These three areas represent the central and paracentral visual fields in the published retinotopic map (Palmer et al., 1978). Convergence eye movements evoked from the caudal PMLS were divided into two groups based on their latencies; the short-latency components (SLC) and long-latency components (LLC). The SLC and the LLC had differences in their symmetry of right and left eye movements during vergence eye movement. The SLC had symmetric right and left eye components and the LLC had dominant contralateral eye components. In the rostral PMLS, latencies of evoked convergence eye movement were comparable to those of the caudal PMLS, but they did not divided into two groups. Convergence eye movements evoked from the PLLS had longer latencies than those from the PMLS and asymmetric right and left eye components. It is suggested that different subregions in the LS cortex contribute to the control of convergence eye movement, playing different roles.