Two examples of submovement composition during head-alone tracking.

<p>Top two rows depict position (top) and velocity (middle) traces, respectively, separated for gaze movement (G; blue), head movement (H; red), eye movement (E, re head; gray), and juice spout motion (J_s; green). Bottom panels depict the profiles of the head velocity (H, thin red) and the minimum-jerk model of head velocity (H_mj, thick gray). Task-associated head movement was selected between the onset (▴) and offset (▾) of juice spout motion. The order of the submovements is coded in color (first: magenta; second: green; third: light blue). Time scale is identical across all plots. To facilitate data comparison, the head movements are plotted in positive directions regardless of whether the movements were rightward or leftward, the other movements were rectified accordingly. Note the goodness of fit in <b>B</b> improved by 55.1% from a single submovement model (#SM = 1; 55.5% error) to two overlapping submovement model (#SM = 2; 0.4% error).