Fig. 5.
Task constraints affect feedback response to perturbations. In this bi-manual task, there are either two cursors visible on a screen or a single cursor. In the two cursor condition, each hand controls one cursor. In the one cursor condition, the average position of each hand is reflected in cursor position. In the top row of this figure, the blue and red arrows show that a perturbation is applied to the left hand. The middle row shows the hand paths in each condition (black trace is the condition without a perturbation). The bottom row shows the hand velocities. In the two cursor condition, perturbation to the left hand is compensated by the left hand only. In the one cursor condition, the same perturbation is compensated by motion of both hands. (from Diedrichsen 2007)