Sample trials of raw data.

Raw data are shown from different participants for whom decreasing levels (from top to bottom) of valid data were collected. X and Y eye positions are shown in blue and orange, respectively. Horizontal plateaus are periods where x and y coordinates of the eye remain relatively steady, indicating fixations. Vertical lines are periods where the eye position is changing rapidly, indicating saccades. Gaps in the traces represent periods of data loss. As the threshold for valid data decreases, there are more frequent gaps in the data and increased noise in the x,y traces.