ROI-wise and vertex-wise analyses are different and may give different results. The vertex-wise analysis looks at individual vertices whereas ROI-wise averages over all the vertices. It is possible (even expected) that averaging over all vertices will reduce the variation and give stronger statistics than vertex-wise.

On 7/2/2021 10:07 AM, Satoko KINA wrote:

     External Email - Use Caution

Hello Freesurfer Developers,

As a result of whole-brain analysis using qdec, specific regions with significant differences between the two groups were depicted (e.g., paracentral cortical thickness). Based on this result, we compared the paracentral region on the Desikan-killiany atlas from aparc.stats between the two groups, and found significant differences not only in CT but also in items rejected by qdec (e.g., curv). How should we interpret this result? Which result is more reliable? Can we consider the result of the analysis focused on a narrow region of each ROI as a more detailed result because qdec is a whole brain analysis? I am not familiar with statistics, so please forgive me if this is a misguided question.

Thank you for help!

Satoko

---

Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer