FIGURE 3.

Decomposition of actual kinematics observed during a double-step. (A) The actual kinematics of a double-step trail (black line) are well-approximated by the sum (gray line) of a primary (light gray) and secondary (dark gray) single-peaked profiles. (B) The single-trial velocity profiles are displayed as heat maps, with the vertical axis representing different trials, and the horizontal axis representing time elapsed within a given trial. The actual kinematics (top left) can be compared to the fit kinematics (top right), which is the sum of the single-trial primary (bottom left) and secondary (bottom right) motions.