Dear SPM
I am applying SVC to certain regions using an a priori hypothesis on uncorrected contrast maps resulting from 2nd level RFX analysis between patients with optic neuritis and controls (fMRI with visual stimulation).
I have some questions
1) Is there a minimum size of SVC that can be applied? If one applies a small enough SVC then a lot of areas can become 'significantly activated'.
2) After applying an SVC to a particular region of the brain and getting for example a significant p value, does this mean that I have to ignore all the other regions of activation in the same map even if some of them are part of my a priori hypothesis?
3) If I want to look at more than one region with SVC can I create a masked volume by modifying the brainmask template in SPM using something like MRIcro? Are there other ways of looking for more that one region?
Thanks
Ahmed Toosy
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