Figure 4.

Stroke subjects had altered spinal maps in both arms. However, the presence of a resistive force field increased the similarity of spinal maps, between arms and among subject populations. (A) The spinal maps obtained for the eight targets in the resistive force (RF) task. The first two rows refer to the right and left arm of controls (C), the third and the fourth rows to the ipsilesional arm (non-paretic) of the left brain (LBD) and right brain (RBD) damage subjects, while the fifth and sixth rows refer to their corresponding contralesional (paretic) arms. On the x-axis, the movement duration is represented as a percentage. Spinal maps refer to equal movements in the joint space, i.e., for each column, the top panel indicates the corresponding target directions (grey target) for the right arm, while the corresponding target directions of the left arm were mirror symmetric with respect to the vertical midline. (B) Mean and standard error of the inter-group similarity (ρ_2D-GROUP) between control (C) and stroke subjects (LBD, red bars; RBD, green bars) in presence of assistive (AF), resistive (RF) and in absence of external force (NF) for the right (bars with uniform color) and left (bars with diagonal lines) arm. The bars with uniform color (right arm) and with diagonal lines (left arm) reflect the intra-group degree of similarity in the control group. The contralesional arm (paretic) corresponds to the left (L) arm in RBD subjects and to the right (R) arm in LBD subjects. The ipsilesional arm (non-paretic) corresponds to the right (R) arm in RBD subjects and the left (L) arm in LBD subjects. (C) Mean and standard error of the between arm similarity (ρ_2D-ARM) for controls (C, black bar), left (LBD, red bar) and right (RBD, green bar) brain damaged in presence of assistive (AF), resistive (RF) and in absence of external force (NF). * indicates significant differences (p < 0.05).