Dear List Users,
Could someone clarify the following for me ?
Following from the recent SVC discussion I was under the impression that
the SVC when applied only includes those voxels (within whatever volume
you have defined) that were initially activated at the previously chosen
uncorrected threshold. In which case the value chosen for this
threshold should dictate the number of voxels within the region where
the SVC is applied and therefore also the resulting p value for the
analysis. However, I find that regardless of the initial threshold
chosen (ie be it 0.01 uncorrected or 0.99 uncorrected) the resulting p
value when the SVC is applied (and the same region is used) is the
same. This would suggest that a small volume correction includes all
those voxels within the pre-defined area that one is analysing
regardless of what threshold was originally chosen for the uncorrected
analysis. Is this is correct, because reading the emails from August on
this subject, I did not think this was the case.
Thank you for your help.