Deflection (1) could be a small saccade, (2) is noise, and (3) and (4) could be caused by short periods when the image recognition procedure of the eye movement camera lost the image of the pupil. Distortion (1) only occurred in the horizontal (blue or uppermost) signal, but (2), (3), and (4) were also present in the vertical (green or middle) and torsional (red or lowest) signals.