Interpretation of results. Hypothetical trajectories in the {RFT;
CFT} space are plotted for different trials. Each trial begins
from a different location, but always close to the hyperbola for perfect
performance, since visual feedback is available. After feedback removal, the
force drops, and the UCM shifts accordingly. The dotted curve represents the UCM
at a later time. The individual trial trajectories show large, irregular motion
along the shifting UCM, and smaller, consistent motion along the direction of
force drop