The affordance of catchability in running to intercept fly balls.

How do outfielders control their locomotor behavior in running to catch fly balls? This question has been the topic of many empirical studies. It is interesting that a little addressed but highly relevant issue in this regard is that of the influence of perceived catchability on locomotor control. We examined what factors determine catchability and whether catchability can be reliably perceived. We had participants run to catch fly balls that could either be catchable or uncatchable. Participants performed two tasks. In the catching task, they were instructed to attempt to catch the ball and to keep running even when they felt that a ball was uncatchable. In the judging task, they were instructed to call "no" as soon as they perceived a ball to be uncatchable. Using Generalized Linear Mixed Effects Regression (GLMER) on data from the catching task, we modeled catchability, identifying five behaviorally relevant agent-environment variables that together explained 84.4% of the variance in catching performance. Next, we examined whether judgments of catchability were accurate. Using the GLMER-model, the catchability of every fly ball in the judging task was predicted and subsequently compared with participants' judgments. Participants were able to correctly judge the catchability of a fly ball on 85.4% of the trials. It is interesting that participants' judgments of fly balls to be uncatchable most often were given only after they had started running. Present findings provide a valuable step toward the formalization of an affordance-based control strategy for running to catch fly balls. (PsycINFO Database Record