Figure 3.

Human visuomotor feedback responses are modulated across the five experimental conditions. A, Lateral perturbations of the cursor were applied in all five conditions. Perturbations were introduced as 2-cm cursor jumps perpendicular to the movement direction. The perturbation onset occurred at one of five equally spaced hand locations. B, Mean velocity profiles of the hand in five experimental conditions: matched-cursor early-peak (green), matched-cursor late-peak (blue), matched-hand early-peak (yellow), matched-hand late-peak (purple), and baseline (gray). Participants successfully modulated forward movement kinematics to meet task demands, velocity profiles are skewed for matched-cursor conditions, and are similar to the baseline for matched-hand conditions. C, Mean visuomotor feedback intensities (mean lateral force from 180 to 230 ms after perturbation onset) across all participants to cursor perturbations as a function of the hand distance in the movement. Error bars represent 1 standard error of the mean (SEM). Significant regulation is observed for matched-cursor early-peak and matched-cursor late-peak conditions (blue and green), but no significant regulation is seen for matched-hand conditions (yellow and purple), relative to the baseline.