Hi,
On Sat, Mar 7, 2015 at 3:41 AM, MCLAREN, Donald
<[log in to unmask]> wrote:
> There are quite different:
> (1) ROI Analysis - this typically means that you select your ROI, extract
> the data, and then run the statistics on the ROI mean/eigenvalues.
> (2) SVC Analysis - this is a voxel-wise analysis within a restricted area of
> the brain. The maps don't change, but the corrected p-values will change
> because you have restricted the search region.
>
> With an ROI analysis, you can test multiple ROIs. With SVC, you have to test
> all regions simultaneously or correct for the number of times you perform an
> SVC.
>
> The math underlying SVC is the same as the whole brain analysis, except the
> search volume is reduced.
There's a marsbar faq topic that might be helpful:
http://marsbar.sourceforge.net/faq.html#should-i-use-marsbar-roi-analysis-or-small-volume-correction-svc-in-spm
Cheers,
Matthew
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