Hello Alfonso,

Thank you for such helpful reply, you answered exactly what I needed to know. I have some follow up quick questions:

1) Is there away to associate vertex indexing in fsaverage surface with subject-specific surface. I see that subject-specfic surface and fsaverage surface do not have the same vertices/faces number, so their respective indexing should not associated to each other in anyway. I understand that subject-specific surface had been morphed into fsaverage space using ?h.sphere.reg (via curvature measures) but I could not figure out how each vertex values in fsaverage space map back to subject-specific space (again they have different number of vertices, also different in xyz locations).

2) I can only do conn_matc2nii on the vvPC_Subject*_Condition*.mat  and NOT on the vvPC_Subject*_Condition*.matc (see Error)Error using load
     Number of columns on line 2 of ASCII file
     vvPC_Subject001_Condition003.matc
     must be the same as previous lines.

     Error in conn_vol (line 3)
     load(filename,'V');
     Error in conn_matc2nii (line 24)
     Y=conn_vol(filename{nfile});
Are they (.mat and .matc) equivalent? (my Matlab is R2013a)

3) As in reshaping the N volumes into matrix B, would concatenate the whole volume into 1 vector (say B = vol(:) ) be appropriate to have correct ordered index?

Thank you for your time and assistance, as always.
Best,
Thinh Nguyen