Functional MRI Preprocessing Pipeline

Imaging data were transferred and processed on a Linux platform running MATLAB version 8.0 (The MathWorks, Natick, Massachusetts, USA). Preprocessing was performed with Statistical Parametric Mapping software (SPM8; Wellcome Trust Centre for Neuroimaging, UK) using a preprocessing pipeline as reported in Kerestes et al.^{24 (link)} In brief, preprocessing involved the following steps: slice timing correction, motion correction, co-registration of each participant's echo planar images to their respective co-registered T₁ image, spatial normalisation of both the structural and functional images (re-sliced to 2 mm) and spatial smoothing with a 6 mm full width half maximum Gaussian filter (see supplementary material for additional information).