Hello

I am trying to analyse my retinotopic data with freesurfer FS-FAST. Regarding the workflow, I found very helpful information on the freesurfer WIKI, except one preprocessing issue:

Instead of smoothing my data in the volume I want to to smooth the retinotopic data on the surface before starting the actual analysis as fieldsign maps are also organised within the plane rather than the 3D volume.

I already tried mri_vol2surf then smoothed my functional data following a re-transformation into volume data using mri_surf2vol. However, after processing the functional data with mri_vol2surf it leaves me with an image of several dimensions rather than 2 (as I expected), which I don't know how to smooth.

So my question is if my approach is the right way to do functional surface smoothing (and if yes how to interpret / smooth the output of mri_vol2surf) or if there is a better solution for my problem I haven't found, yet.

Thanks already in advance!

best wishes

Andreas