Predictive Gaze Shifts and Gaze Tracking with Coincidence-Anticipation Timing Responses

Introduction: Coincidence-anticipation timing (CAT) requires an individual to execute a task at the same time that an approaching object arrives. Previous studies on intercepting a moving object suggest that if the interception location is known, observers quickly shift their gaze to this location. The purpose of this experiment was to qualitatively determine whether a clinical CAT device with a known interception location induces early predictive gaze shifts. Materials and Methods: CAT responses were measured using a Bassin Anticipation Timer consisting of a linear track of lights (3.58m). The lights illuminated sequentially to simulate movement along the track. A wearable video eye tracker was used to record the participants’ gaze location. Participants pushed a button to coincide with illumination of the final light on the track. CAT responses were assessed in 2 conditions. In the nonrandom condition, participants responded to blocks of 21 consecutive presentations at stimulus velocities of 5mph (8.04km/h), 10mph (16.09km/h), and 20mph (32.18km/h) (63 trials). In the random condition, participants responded to randomized stimulus velocities of 5 to 20mph (64 trials). Results: CAT responses were collected from 20 participants. The relationship between CAT errors and stimulus velocity was best fit with a linear function for the nonrandom condition and with a quadratic function for the random condition. Gaze tracking data were examined for 14 participants. Predictive gaze shifts occurred in 23.6% of the trials in the nonrandom condition and 12.4% of trials in the random condition. In trials with no predictive movements, tracking generally occurred for most of the trajectory. Substantial head movements in the direction of the approaching stimulus occurred regularly for most participants. Conclusion: Predictive gaze movements were uncommon in this coincidence-anticipation timing task. Continuous tracking was the most common gaze strategy. Future studies can explore whether training with CAT devices leads to improved sports performance. Keywords: vision, sports, coincidence anticipation timing, eye movements, head movements