Role of motion inertia in dynamic motion integration for smooth pursuit

摘要: Due to the aperture problem, the initial direction of tracking responses to a translating tilted bar is biased towards the direction orthogonal to the orientation of the bar. This directional error is progressively reduced during the initial 200ms of pursuit because of dynamic motion integration. In this work, we have studied dynamics of motion integration at different stages of pursuit by perturbing the translation: Subjects (n= 6) were asked to track the center of a 45 degree tilted bar moving horizontally at a constant speed, while bar disappears for 200 ms (blank) at different times during initial and steady state phases of smooth pursuit. Results suggest that the role of prediction for motion integration is higher in initial phase compared to steady state. We have conducted the same experiments on a probabilistic, motion-based prediction model. The observed dynamic suggests a form of motion inertia in the modeled response which affects error at different stages of prediction. This inertia favors smooth pursuit trajectories path. We have studied how motion inertia changes at different stages of pursuit with respect to blank time and compared it with behavioral results.