Data of participant P5.

Same organization as Fig 5 with C, D, E, F corresponding to E, F, G, H.</p

Description of the experiment.

A. Experimental setup. (left) Top view. The small open circle is the start position and the large open circle the target position. The black circle is the robot handle. The elongated open rectangle is a top view of a monitor. (right) Front view. The start position, target position, and visual feedback of hand position (black circle) are shown on the monitor. The black rectangle is the robot handle. The scales are not respected. B. Simulated velocity-dependent force field. A minimum-jerk velocity profile with a 0.3 m/s peak was multiplied by a 5 N/m force field. Vertical scale: 0.01 m. Horizontal scale: 1 N. C. Experimental protocol. The force field level (null or CW) is indicated by the horizontal black (baseline block), gray (before-effect and adaptation blocks) or green (adapted and after-effect blocks) thick line segments. The vertical line segments indicate catch trials: unexpected CW force field in the before-effect block (red); unexpected null force field in the adaptation block (gray) and in the after-effect block (blue). Only the colored trials (black: baseline; red: before-effect; green: adapted; blue: after-effect) were analyzed. D. Graphical definition of the trajectory angle. At one point along the trajectory (open square), the trajectory angle is the angle between start position/target position direction (dashed line) and the tangent to the trajectory (thick line).</p

Predictions of the compensation model.

A. Simulated trajectories. B. Simulated velocity profiles. (PDF)</p

Model predictions.

A. Simulated adapted (green) and after-effect (blue) trajectories corresponding to simulated baseline (black) and before-effect (red) trajectories shown in Fig 3D and reproduced here with thin lines. Scale: 0.02 m. B. Simulated velocity profiles. C. Trajectory angle for A. D. Trajectory angle derivative for A. E. Zoom on trajectory angle (dotted box in C). F. Zoom on trajectory angle derivative (dotted box in D). Vertical dashed lines indicate the time of change in derivative sign.</p

Time at which the angle derivative of the before-effect trajectory became positive.

A. All participants with mean value (thick line) and 25–75 percentiles (box). B. Data of participant P7 and mean of all the participants. The black dashed line is the model prediction. (PDF)</p

Goal selection vs action selection.

A. The motor system contains: (1) a process, called action selection (AS; purple), which translates a current goal (e.g. a target to reach) into the proper displacement of the current effector (e.g. the arm) toward the goal (the target); (2) a process, called goal selection (GS; orange), which provides the current goal for a given task. B. Schematic of adaptation to a force field perturbation (only the early phase of movement is described). The small circle is the starting position, the double circle the goal position, the black arrow the planned displacement, and the gray arrow the actual (or observed) displacement. (left) For a planned displacement toward the goal position, the force field (black leftward arrows) induces an initial actual displacement in the direction of the perturbation. (center) Adaptation at the AS level consists in keeping the same goal position and applying compensatory forces (purple rightward arrows). (right) Adaptation at the GS level consists in re-aiming toward a new goal position (orange double circle). C. Schematic of adaptation to a rotation of the visual display. (left) For a planned displacement toward the goal position, the rotation induces an initial actual displacement in the direction of the rotation. (center) Adaptation at the AS level consists in keeping the same goal position and applying compensatory rotation (purple rightward arrow). (right) Adaptation at the GS level consists in re-aiming toward a new goal position (orange double circle).</p

Participants whose behavior is incompatible with the reoptimization model.

Same format as in Fig 5. For bf10, the dotted lines correspond, from bottom to top, to substantial =, anecdotal =, anecdotal≠, and substantial≠. (PDF)</p

Simulations of the redirection model.

A. (left) Adapted (green) and after-effect (blue) trajectories corresponding to a series of via-points (squares). (right) Multiple adapted and after-effect trajectories corresponding to variations of the series of via-points. B. Corresponding velocity profiles. C. Corresponding trajectory angles. D. Corresponding trajectory angle derivatives.</p

Model adjustment based on data of participant P7.

A. Mean baseline (black; 17 trials) and before-effect (red; 19 trials) trajectories for P7. Scale: 0.02 m. B. Mean velocity profiles of baseline and before-effect trajectories for P7. C. Velocity (scale 0.1 m/s), acceleration (scale 2 m/s2) and jerk (scale 30 m/s3) profiles for a single baseline trial (P7). Time scale: 0.1 s. D. Simulated baseline (plain black) and before-effect (plain red) trajectories compared to experimental trajectories (dashed; data from A). Squares are via-points for the simulated trajectories. Same scale as in A. E. Simulated velocity profiles. F. Velocity (same as black in E), acceleration and jerk profiles for the simulated baseline trajectory. The profiles have been truncated to match the duration of the trial in C. Same scales as in C. G. Peak frequency for velocity (orange), acceleration (light green) and jerk (light blue) profiles for individual trials (small dots). Large circles correspond to the trial in C. Large squares correspond to the simulated trial in F. Thick lines are mean values and boxes indicate 25–75 percentiles.</p

Participants whose behavior is partially compatible with the reoptimization model.

Same format as S3 Fig. (PDF)</p