Quantitative relation between server motion and receiver anticipation in tennis: implications of responses to computer-simulated motions.

The purpose of this study was to determine the quantitative relationships between the server's motion and the receiver's anticipation using a computer graphic animation of tennis serves. The test motions were determined by capturing the motion of a model player and estimating the computational perturbations caused by modulating the rotation of the player's elbow and forearm joints. Eight experienced and eight novice players rated their anticipation of the speed, direction, and spin of the ball on a visual analogue scale. The experienced players significantly altered some of their anticipatory judgment depending on the percentage of both the forearm and elbow modulations, while the novice players indicated no significant changes. Multiple regression analyses, including that of the racket's kinematic parameters immediately before racket-ball impact as independent variables, showed that the experienced players demonstrated a higher coefficient of determination than the novice players in their anticipatory judgment of the ball direction. The results have implications on the understanding of the functional relation between a player's motion and the opponent's anticipatory judgment during real play.

Expression of emotions in dance: relation between arm movement characteristics and emotion.

This study was designed to investigate the relations between emotional expression and the movement characteristics. For this purpose, we used kinematic data related to three factors of the movement characteristics: Speed, Force, and Directness. In Exp. 1, we examined how the dancers expressed emotions when they used a certain body action and body part, and how they altered the movement characteristics. In Exp. 1, 10 female dancers were instructed to express three emotions, joy, sadness, and anger, by altering arm-movement characteristics. Analysis of variance indicated that the three exhibited emotional expressions had different movement characteristics. Discriminant analysis indicated that kinematic data for evaluation of movement characteristics are useful for discrimination of the three emotional expressions in dance. In Exp. 2, we investigated how naive observers perceived the type of emotion from the arm-movement characteristics. Analysis of variance showed that 22 observers accurately perceived each emotion distinguished from other emotions. Multiple regression analysis showed that specific movement characteristics influenced the perception of particular emotion.

Effect of metaphorical verbal instruction on modeling of sequential dance skills by young children.

Metaphorical verbal instruction was compared to specific verbal instruction about movement in the modeling of sequential dance skills by young children. Two groups of participants (Younger, mean age 5:3 yr., n = 30: Older, mean age 6:2 yr., n = 30) were randomly assigned to conditions in a 2 (sex) x 2 (age [Younger and Older]) x 3 (verbal instruction [Metaphorical, Movement-relevant, and None]) factorial design. Order scores were calculated for both performance and recognition tests, comprising five acquisition trials and two retention trials after 24 hr., respectively. Analysis of variance indicated that the group given metaphorical instruction performed better than the other two instructions for both younger and older children. The results suggest that metaphorical verbal instruction aids the recognition and performance of sequential dance skills in young children.