Figure 5.

Catch trials. Contact force profile against the rigid surface unexpectedly restored. (A–F) Black lines: Parallel control model results. Gray lines: the after effects that would result from the same ideal force controller of Figure 3. (G–L): Experimental results (mean ± s.d. over all subjects) in vision (darker intervals) and no vision condition. Subjects operated in the same condition as in baseline, but the achieved performances were different. The force trajectories showed remarkable after effects: subjects overshoot the target force in the desired forward direction (G). In the lateral direction (H) they made errors opposite to the error in the initial response to the softer environment. These data are consistent with the predictions of the model (A–C). The motion is negligible in both experiment and model data (D–F,J–L). The panels on the right (C,F,I,L) display the vector plots of the applied forces and endpoint motions.