Effect of Manipulating Advanced Kinematic Information on Hitting Movement Prediction, Perception, and Action

Abstract

Purpose: This study examined the effect of manipulating advanced kinematic information about opponents' pitching movement on ball speed prediction, ball speed perception, and impact timing errors under strict temporal constraints (i.e., a softball game). Method: Three experiments were conducted using visual stimuli consisting of varied kinematic information-different pitching movements with the same ball trajectory. In Experiment 1, participants observed the pitching movement of the visual stimuli and predicted pitched ball speed as a two-interval forced choice discrimination task (2IFC). In Experiment 2, participants observed both the pitching movement and ball trajectory, and evaluated the pitched ball speed as a 2IFC. In Experiments 3a and 3b, they tried to swing against the pitched ball presented on the screen as accurately as possible with regard to timing. Results: Batters tended to predict the ball was moving faster when the pitching movement was faster (Experiment 1). Incorrectly predicting the ball speed due to the difference in advanced kinematic information also biased batters' perception of the speed (Experiment 2), and this biased prediction yielded congruent impact timing (Experiment 3a). The impact timing error of naive participants also was affected by kinematic information (Experiment 3b). Conclusion: Limitations of this study (representative task design, sample size, and experimental procedures) notwithstanding, results indicate that, under strict temporal constraints, batters' perceptions and actions are sensitive to advanced kinematic information, which could lead to biased perceptions and actions.

Optimal integration of kinematic and ball-flight information when perceiving the speed of a moving ball

“…Although there was some evidence in the Takamido et al ( 24 ) study to suggest that batters integrated information in an optimal manner, only very tentative conclusions could be drawn because batters saw only manipulations of the pitching movement, and no changes in the actual ball speed. If true integration were to occur, then the information offered by the kinematic action should be weighted more heavily if the ball-flight information were to become less reliable.…”

“…From the viewpoint of ball speed, since angular velocities of various body parts such as the pitching arm are related to ball speed [e.g., ( 22 , 23 )], ball speed is indeed related to the speed of the pitching movement. Recently, Takamido et al ( 24 ) examined this in a softball batting prediction task by manipulating the movement speed of the pitcher's action when batters were required to estimate the speed of an approaching ball. Specifically, a pitching scene was filmed from the batter's perspective, and the pitching movement was edited into a fast or slow movement.…”

“…That is, the batters in this cue-combination task may have performed a maximum likelihood estimation by optimally combining the different cues in a fashion that gave greater weighting to the information that was more reliable ( 36 ). Although the aforementioned study investigated the integration of contextual and ball-trajectory information, this would imply that the changes in perceived ball speed observed by Takamido et al ( 24 ) resulting from changes in the movement speed of the pitcher might also have been caused by a cue-combination process whereby the kinematic and ball-flight information were integrated based on the relative reliability of the two sources. Indeed, in their study, the pitching movement speed did not alter speed judgements in a linear fashion whereby more extreme manipulations increasingly altered the perceived ball speed.…”

“…To achieve our aim, we asked batters to perform a pitch speed-estimation task in a virtual environment in which the reliability of the pitching movement and ball-speed information was systematically manipulated. Specifically, the reliability of the pitching movement was manipulated by modulating the pitching movement speed ( 24 ) and the reliability of the ball-flight information was manipulated by modulating the ball speed. When combining information from the pitching movement speed and ball-speed, there appear to be three possible strategies for the batter to estimate ball speed: (1) a ball-speed strategy; (2) a kinematic strategy; and (3) an optimal integration strategy ( Figure 1 ).…”

“…Conversely, more weight should be given to the ball trajectory information the farther the pitching movement speed moves from the natural speed and therefore is less reliable. Based on the findings of the study by Takamido et al ( 24 ), we expected to find that batters integrate the two sources of information in an optimal manner.…”