Comparison of the effects of spatial smoothing on t-statistics from the GLM output and significantly activated voxel counts for all 15 subjects. T-statistics: as spatial smoothing extent increased, peak t-statistics (in parentheses) decreased and statistically significant (voxel-based thresholding, 5% FWER corrected) increases in t-statistics (* and † symbols) were observed across all grey matter ROIs. The mean t-statistic in all ROI increased after 3 mm smoothing compared to no smoothing, and increased in PoCG and thalamus after 5 mm smoothing compared to 3 mm # active voxels and % white matter: as smoothing extent increased, the number of statistically significant voxels increased, measured using three thresholding approaches. Voxel is FDR corrected; cluster and TFCE are FWER corrected. ACC = anterior cingulate cortex; PoCG = postcentral gyrus; TFCE = threshold free cluster enhancement; * and † = statistically significant difference.