Effect Of Target Type On Accuracy In High-speed Throwing Task

PURPOSE: The goal-criterions such as size of target implicitly influence perceptions of error and interpretations of success during goal-directed motor tasks. Previous studies reported such perceptions of error or success effect on motor performance from an affective aspect as well as information processing/cognitive aspect. This study focused on the effect of whether the target is human or object on accuracy in a high-speed throwing task. METHODS: Six healthy males (23-28 yr) without baseball experience participated in this study. They threw 20 four-seam fastballs each at a catcher’s mitt and a mark on a board positioned 18.44 m away. Both targets were about 0.2 m in width and length, whose center was placed 1 m above the ground. A high-speed camera (960 fps) placed on the participants’ back was used to capture the ball movements. The ball arrival positions were obtained using the camera images in which the center of the ball at the moment of arrival was digitized and a direct linear transformation method. The mean absolute error and variable error of the ball arrival positions were compared between the two target conditions using a pared t-test. RESULTS: The mean absolute error in catcher’s mitt condition was significantly smaller than that in mark condition (catcher’s mitt: 0.35 m, mark: 0.61 m, p < .05). In addition, variable error in catcher’s mitt condition were significantly smaller than that in mark condition only in vertical direction (catcher’s mitt: 0.51 m, mark: 0.93 m, p < .05), but not in horizontal direction (catcher’s mitt: 0.51 m, mark: 0.58 m, p = .08). CONCLUSIONS: These results showed that the difference in target types (human or object) effects on accuracy in a high-speed throwing task. This suggests that these target types had different information processing, cognitive, and affective effects on the throwers' motor control. Furthermore, human target may promote learning or skill aquation, which useful in sports fields.