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Light mobile eye trackers are able to accurately record the gaze as the athlete moves naturally
during a motor task. During all motor tasks, the scene recorded by the eye tracker changes constantly as
the head moves, causing the x/y coordinates to also change. When this occurs, the x/y digital data collected by most eye trackers is not accurate and should not be used.
Instead, the gaze data (fixations, pursuit tracking, saccades) should be coded gaze x gaze using the Quiet Eye Solutions (QES) software. Click on the video (below)
to see a basketball athlete looking at the front, back, right and left side of the hoop as requested. This is a calibration check done before trials to ensure the eye tracker is accurate.
Only during fixations and pursuit tracking gaze is the brain is able to process the information being viewed. Fixations occur when the
gaze is held stable on a location for a minimum of 3 frames of video (or 99.99 ms) within 3 degrees of visual angle or less (foveal vision). Pursuit tracking gaze are
similar to fixations except they are located on objects that move (such as a ball or teammate). Saccades occur when the gaze moves rapidly from one location to another for a
minimum of 2 frames of video data (or 66.66 ms). During saccades the brain suppresses the information viewed. QES automatically outputs the location, onset, offset and duration
of all gaze, as well as the quiet eye (QE) prior to a phase of the movement. The coded data is saved in a .csv file that can be analyzed by any statistical package.
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