Author(s): SHINKAI, R., ANDO, S., NONAKA, Y., KIZUKA, T., ONO, S., Institution: UNIVERSITY OF TSUKUBA, Country: JAPAN, Abstract-ID: 2009

INTRODUCTION:
Eye movements are crucial for acquiring visual information during interceptive performances such as table tennis. Previous studies have indicated that table tennis players spend less time looking at the ball as it approaches them (Ripoll and Flurence, 1988; Rodrigues et al., 2002; Shinkai et al., 2022). However, it is still uncertain where table tennis players direct their gaze after tracking the ball. We hypothesized high skill players in table tennis would direct their gaze toward opposite side of the court because aiming the landing position of the ball they hit back is important based on kinematic information of the opposite player. In addition to gaze direction, attentional direction could enhance our understandings about visual strategies during rallies. Saccade eye movements reflect our attentions relative to visual targets (Hoffman and 77 Subramaniam, 1995). Therefore, we raised an additional hypothesis that the directions of saccades are also the opposite side of the court. Thus, the purpose of this study was to clarify the predictive visual strategies in skilled table tennis players during forehand rallies.
METHODS:
Collegiate male table tennis players (n = 7) wearing an eye-tracking device (Pupil Invisible glasses, Pupil Labs, Berlin) conducted forehand rallies at a constant tempo (100, 120 and 150 bpm) using a metronome. In each tempo condition, participants performed a total of 30 strokes (three conditions). Gaze fixation time, areas of interest where gaze could be directed (Gaze target) and saccade eye movements were detected by video footage of an eye tracking device.
RESULTS:
The mean relative fixation time on the ball approaching participants in each tempo condition was 19.6 ± 2.4 % in the 100 bpm, 19.5 ± 1.5 % in the 120 bpm and 19.4 ± 1.1 % in the 150 bpm. These data indicate that participants gazed at the ball approaching them only 20 % of the time during the rallies. After fixation on the ball approaching participants, most of gaze targets stayed on the opposite court in each tempo condition (100 bpm; 99 % of the total trials, 120 bpm; 100 % of total trials, 150 bpm; 97.7 % of total trials). Furthermore, gaze targets immediately after saccade eye movements tended to be other areas of interest away from the ball location. Thus, not only gaze targets but also the attentional directions were opposite side of the court.
CONCLUSION:
We found that participants gazed at a ball approaching them only 20 % of the time during the rally. Participants tended to gaze at the ball when the opponent hit the ball and move their gaze away from the ball after that. Furthermore, saccades were directed toward the opposite side of the court including the opponent after tracking the ball. These findings suggest that focusing on the opponent’s motion is important for successful forehand table tennis rallies. Taken together, skilled table tennis players are likely to use unique visual strategies for interceptive sports players to estimate spatiotemporal information about the ball.