Hi Maedeh

the surface file should be the one that defines the common coordinate system (usually sphere.reg) and the annotation should refer to a file in the subject's label dir. Every subject in your list must have both files.

cheers Bruce

On Tue, 9 Oct 2018, Maedeh Khalilian wrote:

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Dear Dr.Bruce Fischl Thank you very much for your great sense of responsibility. Sure, i have sent you a zip file named "Maedeh_results"(it was a rather big sized one so i had to send it through Wetranser). Hope you have received it. However, a general question is that, according to freesurfer help the required arguments for "mris_ca_train" are : mris_ca_train [options] <hemi> <canon surf> <annot file> <subject 1> <subject 2> ... <output file>

as it seems it gets one surf file(e.g sphere.reg),and one annotation file, but several subjects...so what does this surface file refer to?should i make an average of all subjects' .reg files? and also for the annotation file ! just one .annot is enough or i have to make an average of several annotation files? if yes, how should i do that? i would be grateful if you could help me. Best regards Maedeh,