Hello users,
I have a an experimental design comprised of 12 runs (between which the
scanner stops briefly but the subject is not moved). I do not have
enough trials per condition within a run to analyze the data
unconcatenated. I am aware that concatenation across runs is not
recommended when avoidable, but given my limitations I have been trying
to determine whether there is any benefit to running my motion
correction unconcatenated and then concatenating the data after the fact.
I have been told that a non-concatenated realign and unwarp would yield
better results across runs, but from my understanding of how the
software works it is not clear to me that is the case. As I understand
it, in a non-concatenated scenario the first image of each run is
aligned with the first of the initial run. The remaining images in a run
are then aligned with their first image. In the concatenated scenario,
every image is aligned to the initial image. Logically there shouldn't
be a difference in accuracy in my case. Am I misunderstanding one or
both of the scenarios? Or is there in fact no benefit to me running my
motion-correction one way or the other?
Thank you very much for your help,
Thackery
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