Eye movements anticipate target rebounds in an interception task

Abstract

Predictive control in humans enables anticipatory behavior by combining sensory feedback with internal forward models. In interception tasks, such predictive processing could enable the visual system to estimate future target positions, thereby facilitating precise and timely motor responses. This study investigated the existence of predictive fixations during a visuomotor task where participants used a joystick to intercept a target that rebounded within a circular arena. We categorized eye movements into fixations, smooth pursuits, and saccades using a threshold-based classification method. The tasks circular geometry simplified trajectory analysis by consistently redirecting the target toward the arenas center after rebounds, enabling clear identification of predictive fixations. Results showed that participants consistently aligned their gaze and joystick movements with the targets anticipated trajectory before rebounds. Similarly, fixation and gaze onsets showed pre-rebound adjustments, using learned statistical regularities of rebounds to anticipate and prepare for changes in the targets trajectory. Directional cues from the targets entry angles just before rebounding influenced gaze alignment and prediction accuracy, while target speeds affected fixation locations. Moreover, masking the target disrupted gaze alignment and increased variability, whereas masking the user had minimal effects, highlighting the importance of target visibility in predictive control. These findings demonstrate the crucial role of predictive fixations in visuomotor coordination, offering a broader understanding of anticipatory behaviors and their applications in dynamic tasks. Our tasks design offers a robust framework for studying predictive processing across individuals, with implications for sports performance, clinical diagnostics, and human-computer interaction.