Fig. 3. Multi-Voxel Pattern Similarity Analyses.

Panels A and B show pattern similarity analyses comparing each group’s second-level group activation maps (i.e. t-statistic maps) with all other groups. These analyses were conducted only on voxels defined based on the NeuroSynth language map (i.e. voxels that passed FDR q<0.01). Panel A shows the similarity matrix (i.e. Pearson correlations) comparing each group’s second-level activation map with every other group. Higher values closer to 1 indicate more pattern similarity, while values closer to 0 indicate no pattern similarity across voxels. The correlation matrix in panel A was converted into a dissimilarity matrix (i.e. 1-r) and entered into canonical multidimensional scaling to reduce the matrix to 2-dimensions (i.e. MDS1 and MDS2) for the purposes of visualization of the separation between ASD Poor and all other groups (panel B). Panels C and D show results of analyses comparing individual subject activation maps (i.e. t-statistic maps) to specific NeuroSynth maps for either ‘Language AND Speech’ or ‘Auditory AND NOT (Language OR Speech)’. Errorbars represent 95% confidence intervals. In all panels the coloring across groups is red = TD, green = LD/DD, blue = ASD Good, and purple = ASD Poor.