Hi Doug,
I have a few queries regarding FWHM used in multiple comparisons correction program mri_glmfit-sim
My data at present is analysed in FSL & Freesurfer following the procedure in the link http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/FslFeatFreeSurfer. No volume based smoothing at single subject level (in FSL) is done at the moment, and a 4 mm surface level smoothing was applied during mris_preproc stage.
1. I have noticed that mri_glmfit computed a FWHM of 8.578114 using residuals. How exactly is this value computed? 2. I understand that the cached simulation used in mri_glmfit-sim is selected based on the above computed smoothness value. Is this fine, or should I override? If I also smooth the data at the single subject level on the volume (in FSL), can I still follow the above process?
Many thanks, Mariam.