Figure 4.

Between arms decoding. A, Illustration of the possible pairs of movement with both arms that may share similar fMRI representations. On the right with a light blue background, movements to different spatial targets using similar joint configuration, which suggest representation in intrinsic/joint coordinates. On the left with a light red background, movements to the same spatial target using different joint configuration, which suggest representation in extrinsic coordinates. B, Mean decoding accuracies between arms across subjects in the ROIs of the both hemispheres (left hemisphere in black, and right hemisphere in gray) and outside the brain. Bars going to the right (light blue background) are for decoding in intrinsic/joint coordinates, and bars going to the left (light red background) are for decoding in extrinsic coordinates. Error bars indicate SEM across subjects. Asterisks indicate significant above-chance decoding accuracies (FDR-corrected for multiple comparisons). C, Whole-brain searchlight analysis between arms. For each cluster of vertices the classifier was trained on trials performed with one arm and tested on trials performed with the other arm. Cortical vertices with between arms decoding accuracies that were significantly above chance across subjects in intrinsic/joint coordinates (blue, p < 0.05, FDR-corrected) or in extrinsic coordinates (red, p < 0.01, FDR-corrected) are marked on inflated hemispheres of a template brain.