Hello SPMers,
I’m doing SPM ROI analysis for three different bilateral regions of interest. Is it possible to do this using a single mask that combines these ROIs? Or do I have to do the ROI analysis with one ROI at a time? When I tried it with a single mask that combined all of my ROIs, SPM did not give me peaks restricted to the mask, but gave me results for the whole brain instead. If I do have to do the ROI analysis for each ROI individually, then would I have to do a Bonferroni correction for the number of ROIs I use (6; 3 bilateral ROIs)? I understand that these results also need to be corrected for multiple voxel-wise comparisons using FWE, FDR, or AlphaSim, and I have used AlphaSim so far. What would the implication of the ROI analysis be for the cluster size determination using AlphaSim? Would I use a cluster threshold for each ROI separately or a cluster threshold for all ROIs combined in one mask?
Thank you for taking the time to read this. I would appreciate any clarification regarding this analysis.
Best,
- Amri
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