Differences in Saccadic Latency and Express Saccades between Skilled and Novice Ball Players in Tracking Predictable and Unpredictable Targets at Two Visual Angles

Summary.-The purpose of the study was to investigate saccadic latency and percentage of express saccades involved in predictable tasks between skilled and novice ball players. Participants performed four different tasks, including time and direction unpredictable task, time predictable task, direction predictable task, and time and direction predictable task at the visual angles of 10 and 20". Skilled ball players had shorter mean saccadic latency than novice players on direction and time and direction predictable tasks. The percentage of express saccades of skilled ball players was higher than that of novice players on the latter. Saccadic latency was shorter in the 10" condition in time and direction unpredictable task and time predictable task than for 20". These results suggested that predictive ability might be one of the general characters distinguishing skilled ball athletes from novices in visuomotor performance. The prediction might reduce the mean difference in the saccadic latency at various visual angles. In sport-specific conditions, athlete's performances are usually superior in complex visuomotor performance compared with that of nonathletes. It is well known that athletes respond more quickly and accurately than nonathletes. Visual search behavior in ball sports plays an important role in picking up the necessary information to guide right actions. In particular, the visual prediction system in ball games plays a crucial role in guiding the athlete's search for essential information basic to their skilled responses. Many researchers showed that skilled ball athletes displayed more appropriate and efficient visual search strategies than their novice counterparts. Williams and Davids (1998) examined the importance of using a movement-based response paradigm to examine prediction in sport. Skilled and novice soccer defenders viewed 1-on-1 and 3-on-3 offensive sequences on a large video projection screen. Analysis showed that skilled soccer players were quicker at responding. The reaction time paradigm has also been used successfully in badminton (Abernethy & Russell, 1987), baseball (Paull & Glencross, 1997), basketball (Tenenbaum, Stewart, & Sheath, 1999), tennis (Tenenbaum, Levi-Kolker, Sade, Lieberman, & Lidor, 1996), and volleyball (Handford & Wil