Integrating visual trajectory and probabilistic information in baseball batting

Objectives: The present study examined how pitch probability and visual trajectory information are integrated to guide motor behavior in a simulated baseball batting task. Design: The reliability of probability information was varied by comparing conditions in which the different simulated pitch types were equiprobable with conditions in which one pitch type had a high probability. The reliability of visual trajectory information was varied by changing the instant at which the simulated ball was occluded (from 50 to 150 ms after pitch release). Method: In Experiment 1 there were two simulated pitch types (fastball and curveball) while in Experiment 2 a third type (changeup) was added. Repeated measures designs were used in both experiments. Results: In both experiments, there were significant probability x occlusion time interactions for both batting performance and batting kinematics. Varying pitch probability had a larger effect on batting performance and led to kinematic changes earlier in the swing when the occlusion was early in the ball's flight as compared to when it was late. Conclusions: Batters can flexibly integrate different sources of information based on their relative reliability and the time at which they become available during the course of the swing.