On 3/6/2020 11:15 AM, Milde, Christopher wrote:
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Dear Freesurfer Experts,
I have a very basic questions about creating subject-wise contrasts between runs
*Background*
Study with two runs per subject where each run corresponds two a different condition (i.e. Stimulation A (on - off) and Stimulation B (on - off).
I performed the preprocessing and 1st levels stats in the native subjects space
*Questions*
- How can I obtain a within-subjects contrast between two runs (the Stimulation A vs. Stimulation B ) obtained in two runs within one session?
The easiest way is to code the conditions differently in the paradigm file (eg, instead of two conditions, you'd have 4, ARun1, BRun1, ARun2, BRun2), then just create contrasts as normal
- Can I obtain this within-subject contrast by staying in the native subject space?
It can be done in fsaverage or the native subject surface space, it is not related.
- Do I have to concatenate both runs and create a new parradigm file?
No, see above
Thanks for your support
Sincerely
Chris
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