Hi everyone, I noticed recently that the smoothness of the minimally-preprocessed grayordinate-space HCP data is surprisingly high, especially at 3T. For subject 100610, as an example, wb_command -cifti-estimate-fwhm reports:
rfMRI_REST1_LR_Atlas_MSMAll_hp2000_clean.dtseries.nii CORTEX_LEFT FWHM: 18.3385 CORTEX_RIGHT FWHM: 16.5479 Voxels FWHM: 7.3608, 7.1032, 6.95473 By contrast, fsl smoothest gives the smoothness of the corresponding volumetric fMRI file as: rfMRI_REST1_LR_hp2000_clean.nii.gz FWHMx = 1.98571 mm, FWHMy = 1.84018 mm, FWHMz = 1.99221 mm That seems like a huge jump in smoothness, especially for the subcortical data, which is represented in essentially the same voxel space. The difference is smaller for the 7T data, but still pronounced: rfMRI_REST1_7T_PA_Atlas_1.6mm_MSMAll_hp2000_clean.dtseries.nii CORTEX_LEFT FWHM: 7.04818 CORTEX_RIGHT FWHM: 6.99358 Voxels FWHM: 4.63357, 4.54396, 4.23441 rfMRI_REST1_7T_PA_hp2000_clean.nii.gz FWHMx = 1.7863 mm, FWHMy = 1.74615 mm, FWHMz = 1.66513 mm Do these results seem correct and if so, why are the grayordinate-space data (including the subcortical voxels) so much smoother? Many thanks, -Ely Example of full workbench command, from subject directory: wb_command -cifti-estimate-fwhm \ MNINonLinear/Results/rfMRI_REST1_LR/rfMRI_REST1_LR_Atlas_MSMAll_hp2000_clean.dtseries.nii \ -merged-volume -column 1 \ -surface CORTEX_LEFT MNINonLinear/fsaverage_LR32k/100610.L.midthickness_MSMAll.32k_fs_LR.surf.gii \ -surface CORTEX_RIGHT MNINonLinear/fsaverage_LR32k/100610.R.midthickness_MSMAll.32k_fs_LR.surf.gii _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users
