Re: [Freesurfer] ROI analysis and whitening in fsfast - Percent activity change

2013-02-14 Thread Clark Fisher
Thanks - it turned out that the zero voxels I put in my fake ROI volumes were causing the cesvar voxels to be misaligned relative to the ces voxels. All seems to be right for the moment. -Clark On Feb 14, 2013, at 12:47 PM, Douglas N Greve wrote: > You can compute the t = ces/sqrt(cesvar) an

Re: [Freesurfer] ROI analysis and whitening in fsfast - Percent activity change

2013-02-14 Thread Douglas N Greve
You can compute the t = ces/sqrt(cesvar) and from that (and the DOF) you can compute the p to see if it is consistent with pValue. doug ps. I don't know that your conf interval formula is correct. I don't have a reason to think it is wrong, I just don't know, so you might want to double check i

Re: [Freesurfer] ROI analysis and whitening in fsfast - Percent activity change

2013-02-14 Thread Clark Fisher
Hi Doug and the list, I think I still have a problem understanding what cesvar.nii contains. As a sanity check, I tried to create 95% confidence intervals around my CES. I found that in some voxels (or ROIs in my case) that had a p-value of less than 0.05, my 95% confidence interval for my CES

Re: [Freesurfer] ROI analysis and whitening in fsfast - Percent activity change

2013-02-13 Thread Douglas N Greve
1). Yes 2) Right, pull the scale outside of the sqrt() doug On 02/13/2013 03:36 PM, Clark Fisher wrote: > Hi Doug, > > Thanks for the help, that seemed to worked great. I have a few > follow up questions about how to process the resulting statistics. > > I'm still using v4.5 (can't switch to

Re: [Freesurfer] ROI analysis and whitening in fsfast - Percent activity change

2013-02-13 Thread Clark Fisher
Hi Doug, Thanks for the help, that seemed to worked great. I have a few follow up questions about how to process the resulting statistics. I'm still using v4.5 (can't switch to v5 yet), as I mentioned, and would like to get the % signal change for certain contrasts with error bars. Looking