Hello,
A few quick questions about the "Per-Run" option in preproc-sess. I understand that in this option, each run's images are registered to the middle timepoint of that run, rather than the first timepoint of the first run. I was wondering, though:
1) Why is this the preferred option instead of per-session? 2) If motion-correction is only done internally to each run, then wouldn't between-run motion throw things off if you wanted to do a GLM spanning the whole scanning session (although I assume it'd be fine for single-run GLMs)? What ensures that the images line up properly between runs?
Thank you very much,
JohnMark
On 12/03/2017 06:35 PM, Taylor, Johnmark wrote:
Hello,
A few quick questions about the "Per-Run" option in preproc-sess. I understand that in this option, each run's images are registered to the middle timepoint of that run, rather than the first timepoint of the first run. I was wondering, though:
- Why is this the preferred option instead of per-session?
The interpolation is less if it is done on a per-run basis, and the registration might be better
- If motion-correction is only done internally to each run, then
wouldn't between-run motion throw things off if you wanted to do a GLM spanning the whole scanning session (although I assume it'd be fine for single-run GLMs)? What ensures that the images line up properly between runs?
That is why we resample into the group atlas space (eg, fsaverage) or the self anatomical space so that all the runs are aligned.
Thank you very much,
JohnMark
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Taylor, Johnmark