Eye Tracking x Table Tennis

Image: Table Tennis

The hand-eye coordination capacity is crucial in table tennis playing. Rapid judgments of both the ball's position and direction are required due to the fast speed of the ball.

When tracking a fast moving object, observers usually do not keep staring at the object through the motion trajectory. Instead, observers are more inclined to predict the location of the object based on the motion trajectory, and quickly move their gaze to the predicted location where the object has not yet arrived. This phenomenon is called predictive saccade.

For cricket players, Land and McLeod (2000) showed that predictive saccades occurred earlier as the batter's skill level increased to predict where the ball would bounce.

Mann et al. (2013) further found that elite cricket players relied on predictive saccades not only to predict the location of ball-bounce but also the location of bat-ball contact

Figure 1: Ganzin Sol Glasses

In table tennis, the ball moves fast, and players also wait for the ball to bounce once before hitting it as playing cricket. Therefore, predictive saccades might also occur in table tennis playing.

Figure 2:The user first looked at the opponent's racket, briefly tracked the ball's movement, and then moved his gaze to a position near the predicted location of ball-bounce.

We recorded a user's eye movements when playing table tennis using the Ganzin SOL wearable eye tracker (Figure 1). The eye-tracking data showed that the user moved his gaze to the opponent's racket position before the opponent hit the ball. The user briefly tracked the ball's movement after the opponent hit the ball. Then, the gaze of the user was moved to a position close to the predicted location of ball-bounce before the ball passed the net (Figure 2).

Figure 3: The location of bat-racket contact deviated from the gaze position.

However, the data also showed that the user's gaze position deviated significantly from the actual contact position at the moment of racket-ball contact, indicating that the user might not have looked at the ball precisely when hitting it (Figure 3).

It is possible the user's performance in table tennis could be improved if he can maintain the gaze on the ball at the moment of racket-ball contact through practice.

Figure 3: The location of bat-racket contact deviated from the gaze position.

However, the data also showed that the user's gaze position deviated significantly from the actual contact position at the moment of racket-ball contact, indicating that the user might not have looked at the ball precisely when hitting it (Figure 3).

It is possible the user's performance in table tennis could be improved if he can maintain the gaze on the ball at the moment of racket-ball contact through practice.

Reference

• Land, M. F., & McLeod, P. (2000). From eye movements to actions: how batsmen hit the ball. Nature neuroscience, 3(12), 1340-1345.
• Mann, D. L., Spratford, W., & Abernethy, B. (2013). The head tracks and gaze predicts: how the world’s best batters hit a ball. PloS ONE, 8(3), e58289.