NITRC Computational Environment is now available
on Amazon Marketplace. Check it out!

That's an interesting idea. I am not sure this is going to work optimally though. You'll only run a rigid-body coregistration between the twins. Even though they have similar brains, this may not be enough to cover up the differences. Also that means that you will use only one of the T1 scan to run the coregistration in stereotaxic space. A better solution would be to have a hierarchical scheme, where twins T1 scans are first (non-linearly) coregistered on each other, before a single transformation to stereotaxic space is estimated. This will however highly bias the data of twin pairs, which will be way better coregistered than between-twins data. This may or may not be a problem (it will be if you are testing some kind of heritability). This may not be easy to work around in any case because the twins's brains are more similar than unrelated brains in the first place. Tough one. Needless to say, no twins coregistration strategy was implemented in NIAK. Could be a neat idea for a summer student though.

I don't relly get where that error could come from. It says it doesn't find the randperm function which doesn't make sense (that's a standard command). There must be something going on with the configuration of the machine that's running the job. I'd try to restart the pipeline a couple of times before giving up and looking for a bug. Let me know if that error is reproducible.