Erin Conway¹, Danica Barron, Troy Smith, Ralph Hale; ¹University of North Georgia

Koerfer et al. (2024) demonstrated that nonrigid vortex motion can create a dissociation between perception of motion and smooth pursuit. In their paradigm, participants view a random dot field that is perturbed by a moving vortex. Because the dots are not moved along with the vortex, smooth pursuit mechanisms fail; however, catch-up saccades compensate for the lack of smooth pursuit gain, allowing participants to perceive and track the vortex’s motion, although the motion may appear unstable and jumpy. This occurs because the system incorrectly assumes static placement of the vortex in space during this process. As a result, a catch-up saccade is initiated when the vortex appears to have jumped from its expected position relative to the eye. In the present study, this effect is tested as a necessary precursor to a larger, ongoing replication-plus-extension design. Participants viewed a black background covered with static white dots and a single dynamic vortex also comprised of white dots that moved at a rate of 10° per second laterally back and forth across the screen. Eye tracker data measured eye position relative to the vortex position, recording eye movements to detect and measure smooth pursuit gains and catch-up saccades. In the absence of visual cues, smooth pursuit was not achieved in the tracking of the vortex. However, ongoing research aims to provide nonvisual multimodal cues that offset the lack of visual cues and facilitate smooth pursuit tracking. This study is the first vital step in improving our understanding of the interaction between various mechanisms that contribute to motion tracking and integration of multisensory stimulation.