they will have the same number of vertices. They will all be in one file, and each vertex is a vertex in fsaverage space, which each subject vertex being mapped to the closest vertex in surface-based atlas. doug
On 10/24/2012 04:34 PM, Gabriel Gonzalez Escamilla wrote:
Thanks Doug,
Does the surface-based thickness approach make possible to compare exactly the same vertex across all my subjects? or they will be still have some differences in the number of vertices among them?
Gabriel
El 24/10/12, *Douglas N Greve * greve@nmr.mgh.harvard.edu escribió:
Hi Gabriel, this sounds like a standard surface-based thickness study. Or am I missing something? In case it is, you can look at the group analysis tutorial. Basically, you run mris_preproc (which puts all of your subjects into the fsaverage space and saves a stack of thickness maps in a single file), then you smooth it, then you run mri_glmfit.
doug
On 10/24/2012 11:47 AM, Gabriel Gonzalez Escamilla wrote:
Dear FreeSurfer experts,
I'm wondering if is it possible to make vertex to vertex comparisons for thickness on a group of subjects. In other words, I have a bunch of subjects pre-processed with FS but I would like to make comparisons finding the thickness values at same vertex in all of them. Is this possible with Freesurfer?
Given that at the beggining all they have different head/brain sizes, I was thinking that a regristration of the surfaces to the same space (FSaverage) would re-sample my data to match in number of vertex. for this, I think that maybe "mri_surf2surf" is capable of such a thing, and then I would have to search for each vertex, or optionally "mris_preproc" using the "-target FSaverage" flag ||*||*would perform something similar.
Please tell me what you think about this?
Many thanks in advanced, Gabriel.
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PhD. student Gabriel González-Escamilla Laboratory of Functional Neuroscience Department of Physiology, Anatomy, and Cell Biology University Pablo de Olavide Ctra. de Utrera, Km.1 41013 - Seville
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