Dear Freesurfer experts,

I haven’t had the pleasure of receiving a response (yet), and was wondering whether that is because more information is needed?

In addition to the general theoretical question, the second part of the question is as important to me: Is there is any way, known to you experts, for me to visualize my SPSS results in a statistical-map-way?

If anyone could spare some time to help me out I would greatly appreciate it!!

Best,

Siri

From: freesurfer-bounces@nmr.mgh.harvard.edu [mailto:freesurfer-bounces@nmr.mgh.harvard.edu] On Behalf Of Noordermeer, S.D.S.
Sent: zaterdag 13 mei 2017 22:22
To: freesurfer@nmr.mgh.harvard.edu
Subject: [Freesurfer] Question - multiple comparisons in FS versus SPSS

Hi there!

I was hoping you could help me with the following 'problem' I am experiencing.

Short background: 

I compared volumetric brain characteristics as output from FreeSurfer parcellations and segmentations between 3 groups, by extracting the volumes per anatomical label from FreeSurfer and analyzing these in SPSS. In SPSS I did a mixed-model analysis, and performed subsequent Benjamini-Hochberg FDR correction for multiple comparisons.

At the moment, I want to make brain maps (because this is a nice way to visualize the data and a reviewer suggested it). However... I believe I end up with only being able to use the uncorrected maps? 

When I perform an FDR-correction (or MonteCarlo, or clusterwise) in FreeSurfer all the group differences disappear. Unfortunately there is nobody that I can consult on this matter in my lab, thus I really hope someone here can help me?
Personally, I think that the difference in the presence (SPSS) versus absence (FS) of groups effects is due to the correction method. I believe that in FreeSurfer I apply a whole brain multiple comparison correction, while in SPSS I merely apply a ROI-based FDR-correction I in SPSS (because I look at volume per label). 

However, I am not sure if this is indeed (theoretically) sound? Could anyone advise me? Is there a way I could visualise my own (SPSS) results?

If more info is needed please do say so, and I will provide it!

Thank you very much for your time and reply!

Best,

Siri