Anticipatory Judgment of Tennis Serve: A Comparison between Video Images and Computer Graphics Animations

Abstract

This study aimed to explore the feasibility of using computer graphics (CG) animations to evaluate perceptual skills in tennis. In Experiment 1, we used video images or CG animations to examine the visual search behaviors and the accuracy of anticipating serve direction of 18 skilled tennis players. Participants viewed the racket area for a longer time during the 150 ms period immediately before the moment of racket-ball contact in the video image condition opposed to the CG animation condition. In addition, the participants made more accurate judgments in the video image condition than in the CG animation condition. In Experiment 2, we investigated the information pick-up patterns of 10 skilled players while they viewed either the video images or CG animations using a temporal occlusion. Consistent with the results of Experiment 1, participants made more accurate judgments during the 150 ms period immediately before the contact in the video image condition than in the CG animation condition. The results of both experiments showed that the perceptual information in the 150 ms period differed between the two film types. However, the anticipation accuracy of the CG animation condition in both experiments was over the chance level (50%), suggesting that the participants were able to pick up the anticipatory information of serve direction from the CG animations. This led to the conclusion that CG animations would be a valuable tool to examine perceptual skills in tennis.Keywords: visual search, temporal occlusion, perceptual skills Paper : Psychology has studied when, where, and how skilled players extract visual cues, using approaches such as eyemovement recording (e.g., Kato and Fukuda, 2002;Savelsbergh et al., 2002;Williams et al., 2002), temporal occlusion (e.g., Abernethy et al., 2001;Farrow et al., 2005;Goulet et al., 1989), and spatial occlusion (e.g., Abernethy and Russell, 1987;Shim et al., 2006;Jackson and Mogan, 2007). Typically, experimental paradigms have presented video displays that simulate the player's perspective while he or she is facing opposing players (e.g., returning a serve in tennis or facing a penalty kick in soccer). These simulated visual stimuli were presented to both skilled and less skilled players, whose task was to anticipate the final outcome of the opponent's motions, for example, identifying the direction in which the ball would be hit. These studies have identified the spatial and temporal visual cues used in anticipatory responses based on differences in skill level.Moreover, previous researchers in sports perception have used point-light displays to examine the minimum essential source of information for skilled performance (Abernethy, 1993;Abernethy et al., 2001;Shim et al., 2005;Ward et al., 2002). The point-light displays represent only the kinematic features of the opponent's movement pattern; however, both skilled and less skilled players in racket sports were able to anticipate movement outcomes from this display (Abernethy et al., 2001;Shim et al., 2006). Ward et al. (20...

A study of kinematic cues and anticipatory performance in tennis using computational manipulation and computer graphics

“…Recently, the effect of using a digital human model for studying the anticipatory performance of a tennis serve was discussed, and a CG display was found to be more similar to a video display rather than to a PLD (Fukuhara et al, 2009). The assessment of a CG display of the manipulated motion in comparison with real world or film remains to be examined.…”

“…The racket model was made of a rigid body polygon. A scripting language (Maya Embedded Language, MEL) was used to convert the motion data to the CG human model (Fukuhara, Ida, Kusubori, & Ishii, 2009). The ball was erased from the animation to eliminate unexpected perceptual effects other than human motion; for example, the racket might miss the ball because the modulation procedure changed the path of the racket.…”

“…It is necessary to evaluate the perceptual effect of digital human models, particularly in comparison with real-world or video displays. The anticipatory performance and visual search strategy when a tennis serve was viewed in order to predict the ball direction have been compared between a CG display with a polygon model and a video display (Fukuhara, Ida, Kusubori, & Ishii, 2009). It was revealed that the polygon model allowed the observers to perceive anticipatory cues from the serve motion, but the response accuracy was lower than that of the video.…”

Recognition of Tennis Serve Performed by a Digital Player: Comparison among Polygon, Shadow, and Stick-Figure Models

“…It has been shown that CG humans could evoke strong brain activity in the superior temporal sulcus, which is involved in the perception of biological motion [21], [22]. Although the response accuracy decreased when viewing CG displays in comparison with video displays, skilled tennis players could pick up anticipatory cues for the direction of the ball from CG animations of the serve motion [23]. The use of a digital human model allows the easily manipulation of the displayed motions on demand, e.g., the contour, texture, and even the motion itself.…”

Can Slow-Motion Footage of Forehand Strokes Be Used to Immediately Improve Anticipatory Judgments in Tennis?

“…We adopted computer graphic (CG) animations as visual stimuli to accurately evaluate recognition errors between the VAS scores and the original coordinate position output from motion capture data. We used CG animations of forehand shots to test the evaluation validity for anticipatory judgment of shot direction ( Fukuhara et al, 2009 ; Fukuhara et al, 2017 ). First, forehand stroke shots by a professional tennis player (22 years old, 11 years of tennis experience, and ranked in the top 30 in Japan) were recorded on the tennis court using three-dimensional motion capture cameras (Hawk system, Motion Analysis Inc.).…”