Hi Carolina, the FWHM is the "full-width/half-maximum" and indicates how much smoothing you have. This is surface-based smoothing, not volume based, and it can be difficult to compare to volume based smoothing as is done in fMRI. The surface-based smoothing can be larger because you don't have to worry about smoothing in white matter and CSF or jumping across a sulcus as you would at higher levels of volume-based smoothing. There is no answer to the actual level of smoothing you need because it depends on how big the blob is. 10mm is "typical". fMRI analysis often has this level of smoothing in the volum.e doug
On 07/07/2012 02:44 PM, carolina.mr wrote:
Hello, In the qdec analysis the default smoothing factor is 10. What does it mean? For other technics such as fMRI we generally use a lower smoothing factor (~3 or lower). What would happen if I low down the FWHM? Thank you, Carolina
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer