Dear Freesurfer experts, 

I am doing a longitudinal repeated measures analysis and I would like to know which smooth is better to use (with the mri_surf2surf command).

In the repeated measures guide  (MailScanner has detected a possible fraud attempt from "secure-web.cisco.com" claiming to be https://surfer.nmr.mgh.harvard.edu/fswiki/RepeatedMeasuresAnova), the example includes an spatial smooth of 5mm FWHM, but in the group analysis guide (MailScanner has detected a possible fraud attempt from "secure-web.cisco.com" claiming to be https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/GroupAnalysisV6.0), the example includes a smooth of 10mm. 

Which one would be more appropriate? And, does it depend on the kind of analysis I am doing (e.g., longitudinal analysis VS a simple group analysis)?

Thank you very much in advance. 

Kind regards, 

Agurne Sampedro