Fig. 5: Associations of hair mercury level with mean diffusivity (MD) (Nā=ā919).

Greater hair mercury level was significantly associated with lower MD in widespread bilateral gray and white matter areas. Colored bars indicate TFCE scores. TFCE score is unit-free and reflects both voxelās height and the sum of the spatially contiguous voxels supporting it; therefore, it reflects both the strength and extent of effects. All results are overlaid on a single-subject T1-weighted SPM8 image. a Regions with significant correlations. The results shown were obtained at a threshold Pā<ā0.05, corrected for multiple comparisons based on 5000 permutations using the TFCE score. b Partial residual plots with trend line depicting the associations between residuals of log (hair mercury) and residuals of mean MD in the significant cluster spread across the right hemisphere, with other confounding factors controlled.