Hello,

I am a research assistant and am trying to carry out a region of interest analysis on a specific functional part of the brain, the Left Superior Temporal Gyrus (LSTG). I do not myself work with afni but work with other students who have experience. What I have is a list of anatomical IJK coordinates exported from a Talairached brain. Then, using a functional data set from this same subject, my coworker exported a list of the functional IJK coordinates that correspond to the region of interest (the LSTG).

However, we are having problems because these two coordinate sets do not match. I have been told that this problem results from a difference between functional vs. anatomical IJK coordinates. More specifically I was told the ranges of the I,J,K values differed between functional and anatomical. I have also heard that xyz coordinates should match between the two. Does anyone know if this is true?

If this is correct, it would seem a lot more logical to switch to xyz coordinates, since it is crucial that the ROI coordinates match the original data for the ROI analysis.

I have suggested this approach but don't have any expertise on this specific issues.

Thanks for the help!

John Sheppard