Preprocessing of Multimodal Neuroimaging Data

T1-weighted structural images and resting-state functional images were preprocessed with SPM8 (Wellcome Trust Centre for Neuroimaging, University College London, UK) running on MATLAB R2019a (MathWorks, Inc., Natick, MA, USA). The functional images were corrected for slice-timing and subsequently realigned to the mean image. Next, using the associated parameters obtained through the segmentation of the T1-weighted structural images coregistered to the mean functional image, the fMRI data were normalized and resampled in 2 × 2 × 2 mm³ voxels. All functional images were then smoothed using an isotropic 6-mm full-width half-maximum Gaussian kernel. Finally, a scrubbing procedure^{58 (link)} was used to compensate further for motion, removing any volume (i.e., functional images) with excessive movement (frame displacement > 0.5 mm), based on the relative changes from frame to frame in the fMRI time-series (Supplementary Table S2 for a summary of head motion).