Rs-FC analysis
After the processing of rs-fMRI data, we used the predefined seed regions for voxel-wise rs- FC analyses using the DPARSF toolbox. The mean time course of all voxels in each seed ROI was used to calculate voxel-wise linear correlations (Pearson’s correlation) in the whole brain during the rs-fMRI period. Individuals’ r values were normalized to z values using Fisher’s z transformation. At the group level, each image pertaining to z values reflecting a correlation between the seed ROI and each voxel of the brain was entered into a random effect two-sample t-test to identify the whole-brain regions showing significant differences between the groups with ASD and TD. In seed-based rs-FC analyses, global time series, computed across all brain voxels, along with six motion parameters, were used as additional covariates to remove confounding effects of physiologic noise and participant movement. For the presentation purpose, rs-FCs from the aMPFC and PCC seed ROIs are shown separately for each group at the threshold of P = 0.05 with a family wise error correction.
Results were corrected between group comparisons, set at P = 0.001, uncorrected at peak level, and P = 0.05 with cluster level.