Hi, I'm not Alfonso but maybe I can help you.

First of all, I don't know if these CAT12 outputs are applicable to CONN, but I'm sure that Alfonso can bring some light to this issue. But maybe you can try to transform the CAT12 derived images to .nii format (https://www.researchgate.net/post/How_to... this post discusses that issue) and once you have the images of each hemisphere in .nii format you could use the function to sume images (syntax = i1 +i2) provided in the ImCalc section of SPM12 (merging the images into a single .nii file). Again, I have no idea if it is correct to use the CAT12 outputs in CONN or if it is possible to convert from .gii to .nii format since they are quite differents.

Best regards.

Benxamin