Figure 1

Kinematics and adaptation curve in the PoMLab experiments. (A) Trajectories displayed on the tablet monitor. The green, blue, and solid black lines denote the averaged trajectories across the PD patients, the age- and MMSE-matched elderly individuals, and young individuals, respectively, in every five trials (N = 18 in each group). The red, white, and magenta circles indicate the initial position, the controlled cursor, and the target, respectively. (B) Measured velocity. The green, blue, and solid black lines denote the averaged velocities along the y-axis across the PD patients, the age- and MMSE-matched elderly individuals, and the young individuals, respectively, in every five trials. (C) Adaptation curves and the perturbation schedule. The horizontal axis denotes the trial number, and the vertical axis indicates the adaptation effects or the degree of perturbation (black dotted line). The adaptation effects were calculated based on the movement angles at the time when the velocity along the y-axis reached its maximal value. The green, blue, and solid black lines indicate the adaptation effects averaged across the PD patients, the age- and MMSE-matched elderly individuals, and the young individuals, respectively. The green, blue, and black shaded areas indicate the standard error of the mean for the adaptation effects in each group. The gray shaded area denotes the trial number where adaptation effects in all the groups are significantly different from zero (t-test p < 0.01 [corrected]). (D) Adaptation effects averaged across the trials denoted in the gray shaded area in panel (C). Each dot indicates the adaptation effects for each subject. Each bar shows the mean adaptation effects in each group. * and ** indicate statistically significant differences with p < 0.05 and p < 0.01, respectively (Tukey’s post hoc test following one-way ANOVA). (E) RMSE averaged across the trials denoted in the gray shaded area in panel (C).