Figure 1.

Composition and decomposition experiments. In the uncoupled phase (A), the hands were unlinked and orthogonal curl field components were applied to each arm. The task involved making out-and-back movements with two cursors (displayed as the small filled circles with lines attached to the hand positions) from a central home position (shown as the unfilled circle) to one of eight targets (shown as the gray filled circles). In the coupled phase (B), the same task was performed, but the arms were linked with a stiff virtual spring and the arms experienced a full curl field.