Fig. 5

Regions of grey matter (top left panel and bottom panel) and white matter (top right panel) changes that correlate with working memory and motor speech/phonology components. Findings for working memory component displayed in top left and right panels and findings for motor speech/phonology component displayed in bottom panel. PCA, grey, and white matter analyses were conducted in the combined PPA group (N = 47). For VBM, coloured voxels indicate regions that emerged as significant in the voxel-based morphometry analyses at a threshold of p < .001 uncorrected for multiple comparisons with a cluster threshold of 50 contiguous voxels. Age, total intracranial volume, and testing site were included as covariates in the analyses. Clusters are overlaid on the MNI standard brain with x, y, and z coordinates reported in MNI standard space. For NBS, black spheres indicate cortical nodes whose edges (gold lines) emerged significant at p < .001 uncorrected for multiple comparisons. Edge thickness corresponds to corresponding effect size (i.e., t-value). Age and testing site were included as covariates in the analyses. No correlations emerged in the NBS for the Motor Speech/Phonology component. L left, R right, PCA principal component analysis, PPA primary progressive aphasia, PCC posterior cingulate cortex, ACC anterior cingulate cortex, OFC orbitofrontal cortex, FFG fusiform gyrus, VBM voxel-based morphometry, NBS network-based statistics