Fig. 3. PSV-seed FC differences between HCs and PD-PIGD patients across disease stages.

a Average seed-to-voxel FC maps for the PSV-seed within each group (HC, HY1, HY2, and HY3–4). Warm/cool colors indicate positive/negative correlations, thresholded for visualization. b Brain regions showing significant group differences in PSV-seeded FC, identified by a whole-brain voxelwise GLM comparing the four groups (F test map). Maps are thresholded at voxel-level p < 0.001 (uncorrected) and cluster-level p_FDR < 0.05. The color bar indicates the F-statistic values. c Bar graph showing the mean Fisher z-transformed FC values extracted from the significant clusters identified in (b) across the four groups (HC, HY1, HY2, and HY3–4); the error bars represent the standard error of the mean. d Post hoc pairwise group comparisons (HY1 vs. HC, HY3-4 vs. HC, and HY3–4 vs. HY1). The brain maps depict regions showing significant differences in connectivity (T-maps; warm colors: increased connectivity in the first group relative to the second; cool colors: decreased connectivity in the first group relative to the second). Statistical thresholds were set at a voxel-level of p < 0.001 (uncorrected) and cluster-level of p_FDR < 0.05. Cluster labels: a L_PCL (left paracentral lobule); b R_PCG (right precentral gyrus); c L_FG (left fusiform gyrus); d R_Put (right putamen); e R_Crus II (right cerebellar crus II).