Head tracking movements and eye-head combined gaze shifts distinguished by normalized peak velocity (peak velocity×duration⁻¹) as a function of submovement amplitude.

<p>Peak velocity and duration are computed after the example shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047565#pone-0047565-g006" target="_blank">Figure 6</a>. Data is plotted as mean ± S.D. Note the submovements exhibited relatively higher normalized peak velocity during eye-head combined gaze shifts compared to head tracking movement. This tendency persisted independent of movement amplitude and the order of the submovements.