Adaptive Eye Movement Behavior for Actions in Younger and Older Adults.

Humans use eye movements to track and interact with moving objects. When motion trajectories are predictable, gaze shifts to future locations, such as a ball's bounce point, could help to overcome sensorimotor delays associated with the ball's future trajectory. These delays can become more pronounced with aging. This study examined whether older adults compensate for sensorimotor delays through stronger reliance on predictive gaze shifts to positions of interest. We recorded gaze and hand movements of younger and older adults playing an iPad version of 'Pong' against an automated opponent. Participants moved either a large or small paddle to intercept a ball that moved at two possible constant speeds and bounced off side walls. Both groups intercepted fewer balls when the paddle was small and the ball moved faster. Contrary to our hypothesis, older participants looked later than younger adults to the final wall bounce before the ball approached their paddle. However, they shifted their gaze earlier to their own paddle before interception, especially in the early phases of the experiment. Importantly, predictive gaze shifts to the ball's final bounce location were strongly linked to better performance. The adoption of predictive gaze shifts became more pronounced with more exposure to the experiment, in both groups, indicating preserved learning and adaptive mechanisms across the lifespan. Overall, gaze allocation patterns remained similar across age groups, but aging specifically enhanced predictive gaze to where manual interactions are expected to happen.