 |
 |
You will have to exclude those subjects from group analysis, then. ________________________________________ From: SPM (Statistical Parametric Mapping) [[log in to unmask]] on behalf of INDIRA CARLENE TURNEY [[log in to unmask]] Sent: Saturday, December 28, 2013 1:04 PM To: [log in to unmask] Subject: Re: [SPM] Drop out Correction w/ Mask? Hi Helmut, Thank you for your response relating to creating a mask for the top of the head drop out in the RFX. So I get that since one subject has low intensity, due to top of the head cut off, the rfx will automatically not have single in that region as well. However, I would like the rfx to show me the signal in that area as only one or two subjects has this dropout. Instead, the rfx currently shows activity every where else with a clear cut off (no activity/signal) at the top of the head. How do i get the rfx to show data in that region? I thought this is where you use a mask. I appreciate your feedback. Indira On Sat, Dec 28, 2013 at 12:41 PM, H. Nebl <[log in to unmask]> wrote: Dear Indira, the RFX will be based on those voxels which have non-NaN values in all of the single-subject models. The single-subject models are based on those voxels surpassing a certain intensity threshold specified in spm_defaults.m So if the top of the head is excluded / has low intensity in one subject this region will not be part of the corresponding single-subject model, and not part of the RFX automatically. A mask is not required. Hope this helps, Helmut