Hi Sofie, please remember to post to the list. The trickiness is that if you map the lh to the rh, then there will be interpoolation in the lh that is not in the rh which can cause a false difference. Our symmetric stream is set up to avoid this problem.
doug
On 01/09/2014 04:39 AM, Sofie Valk wrote:
Dear Doug,
thanks, yes it does make some sense. Can I ask what the trickiness is you refer to, when mapping rh on lh? Sofie
----- Original Message ----- From: "Douglas N Greve" greve@nmr.mgh.harvard.edu To: freesurfer@nmr.mgh.harvard.edu Sent: Wednesday, January 8, 2014 9:11:04 PM Subject: Re: [Freesurfer] xhemi vertices
To follow up, it is intended that you will map both hemispheres of a given subject to one of the hemispheres of fsaverage_sym (it does not matter which, but we usually use lh). You can then do the comparisons on that hemisphere. Does that make sense? doug
On 01/08/2014 02:09 PM, Bruce Fischl wrote:
Hi Sofie,
no, they don't correspond. You need to use mri_surf2surf to map one to the other (which is a bit tricky).
cheers Bruce On Wed, 8 Jan 2014, Sofie Valk wrote:
Dear Free Surfers,
I have a short question regarding the mapping of vertices of the fsaverage_sym, how do vertices in the left hemisphere correspond to vertices in the right hemisphere? When I tested it, it did not seem that the first-indexed vertex on the left hemisphere corresponded to the first-indexed vertex on the right hemisphere defined by me as : (total vertexes/2 + 1) if so, how to calculate the difference between lh and rh?
Thank you very much!!
Kind regards,
Sofie Valk
...
PhD Candidate, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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