Abstract: PURPOSE: Professional baseball batters have less than 500 ms to make a swing yet they manage to contact the ball most of the time. Here we examined whether baseball players have superior eye tracking and manual control capabilities and how they relate to real-world batting.
METHODS: First, we tested professional baseball players from Hong Kong leagues (n=44, 27 females) and demographically-matched non-athletes (n=47, 27 females) using an eye tracking task in which participants visually tracked step-ramp motion that varied unpredictably from trial to trial. Next, we used a manual control task in which participants used a joystick to center a randomly-moving target. Last, to test whether eye tracking and manual control performance predict batting performance, we measured infield batting for a subset of players (n=23, all females, 3-18 years' experience).
RESULTS: For eye tracking, baseball players showed shorter initiation latency, larger steady-state pursuit gain, smaller catch-up saccade amplitude, smaller vertical-horizontal asymmetry, smaller direction-tuning noise, and larger speed responsiveness than non-athletes. For manual control, baseball players showed better control precision, higher response amplitude, and shorter delay than non-athletes. We then used the non-athletes' dataset as a normative standard and computed the baseball-related eye tracking and manual control indices. Notably, baseball players' eye tracking index was significantly correlated with their manual control index (Pearson's r: 0.31, p<0.05) whereas no such correlations were observed in non-athletes. Furthermore, the predictive power of both eye tracking and manual control to baseball hitting performance increased with the baseball experiences, yet the eye tracking but not manual control capabilities can significantly predict batting accuracy for professional baseball players.
CONCLUSIONS: Our sample of professional baseball players showed superior eye tracking and manual control capabilities, as well as coordination between eye-hand control that was absent in non-athletes. Our findings show that real-world baseball batting develops within the players' visuomotor limits.