Achievement

IGERT trainee Elio Santos (Psychology, advisor E. Kowler) and IGERT associate Edinah Gnang (Computer Science) studied smooth pursuit eye movements with patterns of moving random dots. Dots were continually disappearing and reappearing, thus the patterns generated global motion signals, but did not give the impression of a coherent object moving over space. Anticipatory smooth eye movements (smooth pursuit that begins before the onset of target motion) were prominent, but their velocity did not depend on dot lifetime. By contrast, both peak eye velocity and the velocity of steady-state pursuit varied with lifetime. Finding anticipatory pursuit with limited-lifetime random dot patterns shows that anticipatory movements can be triggered by expectations of global motion (perceiving a coherent object is not required). The differential effects of dot lifetime on anticipatory and steady-state pursuit suggests that these eye movements may have different neural origins.