Figure 2

Kinematic measures during imitation of object-directed actions: each measure is presented for imitation of elevated vs. direct trajectories in reach and transfer segments of the sequences. Plots show means with SEM error bars; dots represent individual participants. (A) Vertical amplitude was significantly higher for elevated vs. direct trials (indicating imitation of trajectory) and for transfer vs. reach segments. There was a non-significant trend for reduced vertical amplitude modulation in the PD group. Reference lines indicate model kinematics for the direct (red dashed line) and elevated (blue dashed line) trajectories. (B) Horizontal amplitude did not differ significantly between groups, but movements were longer in elevated vs. direct trials in the transfer segment in the PD group. (C) Peak velocity was significantly higher in the control group, as well as for direct vs. elevated trials and reach vs. transfer segments. (D) Dimensionless jerk was significantly higher in the PD group, particularly for elevated movements.