Figure 2

Reduced gray matter volume in the primary motor cortex contralateral to the affected hand. (a) Decreased gray matter volume (46 voxels) in left-sided injured participants compared to control participants in the right precentral gyrus (local maximum, X, Y, Z = 40, −16, 50; t₂₅ = 3.4) revealed by SVC-analysis with left-sided injured patients. Effect (red) shown on axial, coronal and sagittal slices of the averaged brain calculated across the participant-specific T1-weighted images (n = 32) after being normalized to the MNI brain template. M, medial; L, lateral; A, anterior; P, posterior. Arrows denote central sulcus. (b) Distribution of gray matter volume for the left-sided nerve-injured participants (red filled circles) and for the control participants (black open circles) in the detected zone normalized to the mean value of the controls (n.u., normalized units; see Methods). “Diff”. indicates effect size given as mean difference (and standard error) in percent between the volumes obtained for the injured and the control group and “C. d” gives standardized effect size provided as Cohen’s d (and standard error of the effect size estimate).