Dear SPM-experts,
Currently I am trying to export beta-values during a region of interest (ROI)-analysis in SPM12 (by using a ROI mask from the AAL atlas) from a one sample t-test at second level. Could anyone explain where the number of beta-values is coming from in SPM for a one sample t-test?
Previously I have extracted beta weights from a flexible factorial without any issues (just by using the SPM GUI, without any other toolboxes like Marsbar). Then, the amount of beta values lined up with the amount of subjects x sessions I had. E.g. if I had 30 subjects with 2 scans/sessions, the number of extracted beta values was 60. However, currently, with the one sample t-test, I get a way different number of beta values and I do not see how it relates back to my design. I checked the SPM batch and the right files seemed to be inputted, which are also correctly listed in SPM.xY.P. I also noted that the number of beta values for this one sample t-test seemed to differ per ROI.
In case someone would be able to explain what is happening (or if anything seems to be off) that would be greatly appreciated!
Thanks a lot in advance!
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