Marvin Petersen

@petersenm.bsky.social

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Neuroimaging • Networks • Nature Postdoc at Vascular Cognitive Impairment Lab, UMC Utrecht

Comparison of label permutation-based lesion network mapping and voxel-based lesion-symptom mapping (VLSM). For each cognitive domain, lesion network mapping (LNM) results thresholded at pFDR < 0.05 (red) are overlaid with VLSM maps (blue). Dice coefficients reported in each panel quantify the overlap between methods after significance thresholding for each outcome. Permutation-based LNM maps showed only partial overlap with VLSM maps for the same outcomes, suggesting that even under label permutation testing, LNM captures effects that are not simply reducible to focal lesion-symptom associations.
Comparison of parametric and label-permutation inference in symptom-linked lesion network mapping. For each cognitive domain, group-level lesion network maps thresholded at pFDR < 0.05 are shown for parametric voxelwise inference (blue) overlaid with label permutation maps (red; appearing darkblue where overlapping; note that no voxels light up red, because all label permutation map voxels overlap with parametric voxels). Dice coefficients report the overlap between parametric and label permutation maps after significance thresholding for each outcome.
Permutation-based inference reduces convergence toward degree-like structure and decreases cross-domain similarity. (a) Symptom-linked lesion network maps derived using label permutation, thresholded at pFDR < 0.05. (b) Pairwise comparisons of label-permutation lesion network maps. Upper triangle: similarity quantified as Dice overlap of significance-thresholded maps. The first row/column compares each map with the normative connectome degree map (degree defined as the row-sum of the normative FC matrix; binary degree mask thresholded at the 95th percentile). Lower triangle: pairwise overlaps of significance-thresholded maps; maps corresponding to columns are shown in blue and rows in red. Diagonal: volumes of thresholded masks (mm³).
Parametric symptom-linked lesion network mapping yields highly similar maps across cognitive domains. (a) Symptom-linked lesion network maps derived from parametric statistics, thresholded at pFDR < 0.05. (b) Pairwise comparisons of symptom-linked maps. Upper triangle: similarity quantified as Dice overlap of thresholded maps and Pearson correlation (r) of voxelwise T-statistics. The first row/column compares each symptom-linked map with the normative connectome degree map (degree defined as the row-sum of the normative FC matrix; binary degree mask thresholded at the 95th percentile). Lower triangle: voxelwise scatterplots of T-statistics. Diagonal: volumes of thresholded masks (mm³).