Properties of time-related adaptation in human smooth pursuit eye movements

Abstract

Visuomotor adaptation associated with gain and timing control plays a crucial role in precise control of eye movements. It has been shown that smooth pursuit gain adaptation is induced by repeated trials of a step-ramp tracking with two different velocities (double-step paradigm). In this study, we attempted to determine whether a double-step paradigm with different timing produces pursuit gain adaptation at a specific time. We use a double-step paradigm where target speed changes 400 ms or 800 ms after the target onset during a steady-state pursuit phase. After repeated presentation of this paradigm, pursuit gain showed a significant adaptive change, which was associated with the time when the target speed changed. Furthermore, adaptive capabilities for specific timing were different between humans and monkeys. These results suggest that human pursuit adaptation occurred at a specific time could be due to timing control mechanisms associated with motor preparation.