Hello! I'm a new student to surface based fMRI analysis. Now I'm dealing with a functional parcellation problem. The subjects in my dataset has different vertex number and I need to do a group level parcellation, so I decided to make a group reference template.

        My step is almost following this post: https://www.mail-archive.com/freesurfer@surfer.nmr.mgh.harvard.edu/msg00420.html ,the lh.wholebrain.tif and lh.sphere.reg for two test subjects have successfully generated. But I'm still wondering about these files and what to do next to get my individual fMRI time series on vertex registerd to the template.

        The second question is, the vertex number (~100000) is much more than my voxel based masked data (~50000). Neither is easy to do the susequent analysis efficiently. So how should I correctly downsample it? Should I downsample the template or downsample my surface before making template? Will mris_decimate work?

        The last question is my subject has gifti format sulc and curv data (.shape.gii). I have tried to use MRI_read and MRI_write to write to an .mgh file and add -sulc sulc.mgh for each command and they seems worked. Can I convert them to file like .sulc? Or just keep the .mgh and -sulc sulc.mgh is OK?

        I'm looking forward to hear your reply! Really thanks for your help!

Best wishes,

Jingyue Zhang