Figure 4. Performance of the model (M0 condition) for simulation 1 and the robotic experiment.

Left column: arm movements performed during simulation 1 in the sagittal plane with no additional mass (M0) during the first (first row), second (second row) and third session (third row). Performed (dashed trace) and desired (continued trace) angular displacement. Red and blue traces: up and down movements respectively. Second column: Arm movements under zero gravity conditions after learning under normal gravity condition, Session I, II and III, no additional mass (M0). Third column: Robot arm movements in the sagittal plane with no additional mass (M0) during the first, second and third session.