Thanks for your reply, Doug. Registering both LH and RH to fsaverage_sym worked 
great.

As a preliminary step I am performing a group analyses with images reregistered 
to the regular fsaverage using mris_apply_reg.

However, at the group level it is recognizing that the analyses were carried 
out on -self and throwing the error 
"Analysis space is self surface, not supported"
 
So I presume I am going to come across the same problem with the images 
reregistered to fsaverage_sym if I do the analyses like you suggested?

How can I proceed using isxconcat without rerunning the 1st level analyses in 
the average template spaces?


Thanks!
James


> On 1. nov. 2016, at 18.33, Douglas N Greve <[email protected]> wrote:
> 
> But how did you do the analysis on fsaverage_sym? Not that you cannot 
> just supply fsaverage_sym to preproc-sess. It is unfortunately much more 
> complicated than that. Before you use fsaverage_sym, you must first run 
> the commands here: http://surfer.nmr.mgh.harvard.edu/fswiki/Xhemi
> 
> 
> If you  have a map on the individual for both lh and rh, you can run
> 
> 
> mris_apply_reg --src lh.map.mgh --trg lh.map.lh.fsaverage_sym.mgh 
> --streg $SUBJECTS_DIR/subject/surf/lh.fsaverage_sym.sphere.reg 
> $FREESURFER_HOM/subjects/fsaverage_sym/surf/lh.sphere.reg
> 
> 
> mris_apply_reg --src rh.map.mgh --trg rh.map.lh.fsaverage_sym.mgh 
> --streg $SUBJECTS_DIR/subject/xhemi/surf/lh.fsaverage_sym.sphere.reg 
> $FREESURFER_HOM/subjects/fsaverage_sym/surf/lh.sphere.reg
> 
> 
> You now how lh.map and rh.map on the lh of fsaverage_sym (and so in 
> vertex-for-vertex alignment). You can look at with with
> 
> tksurfer fsaverage_sym lh inflated -aparc -ov 
> lh.map.lh.fsaverage_sym.mgh -ov rh.map.lh.fsaverage_sym.mgh
> 
> 
> These will be two different overlays (lh and rh), so one does not expect 
> them to be identical.
> 
> 
> 
> 
> 
>> On 10/31/2016 11:52 AM, James Roe wrote:
>> 
>> Hi Doug
>> 
>> 
>> Thanks for the reply. It's actually just a normal first level 
>> fMRI analysis ran once on subj1 and once on subj1 after flipping 
>> the anatomical and BOLD data for subj1. After flipping I ran recon-all 
>> on the flipped subject (treating as new subject - so for this sub LH 
>> == RH)
>> 
>> 
>> Top left images = fMRI for subj1​ and subj1_flipped     - smoothing 
>> and analysis performed on fsaverage_sym
>> 
>> Top right images =     ​fMRI for subj1​ and subj1_flipped 
>>    - smoothing and analysis performed on individual surface (with --self)
>> 
>> 
>> The images below are the respective analyses resampled onto the 
>> surface in which the analysis was not performed
>> 
>> 
>> I expected the output to be symmetrical (because input is subj1 and 
>> subj1_flipped).
>> 
>> However, the analysis performed on fsaverage_sym comes out less 
>> symmetrcial than when performed on --self
>> 
>> 
>> I was wondering if you know why this is?
>> 
>> (Resampling each onto the other surface I think shows that it is not a 
>> bias introduced during recon-all of subj1_flipped because the output 
>> is still more symmetrical when performed on individual surface and 
>> resampled onto fsaverage_sym)
>> 
>> 
>> thanks!
>> 
>> 
>> James
>> 
>> 
>> ------------------------------------------------------------------------
>> *From:* [email protected] 
>> <[email protected]> on behalf of Douglas Greve 
>> <[email protected]>
>> *Sent:* 28 October 2016 18:20
>> *To:* [email protected]
>> *Subject:* Re: [Freesurfer] fsaverage_sym LR-flipchecks
>> 
>> Hi James, this looks like a fairly complicated analysis, and I'm not 
>> sure I understand it all. Are the overlays fMRI or thickness results? 
>> How did you generate, for example, the top left images?
>> 
>> 
>>> On 10/26/16 3:15 AM, James Roe wrote:
>>> 
>>> ​
>>> 
>>> Hi Freesurfer experts
>>> 
>>> I have an ultimate goal of performing direct LH v RH comparisons 
>>> using the fsaverage_sym template, so these pre-analysis steps are 
>>> aiming to assess the symmetry of the template.
>>> 
>>> I have performed a first-level fMRI analysis on a subject and am 
>>> using this to compare the output with the exact same analysis 
>>> performed on the same subject with LR-flipped data (anatomical, BOLD 
>>> runs and B0 maps). I then ran recon-all on this flipped subject 
>>> (treating flipped subject as new subject).
>>> 
>>> Attached is a screenshot showing the different analysis outputs.
>>> 
>>> In the top left image, analyses have been performed and smoothed on 
>>> fsaverage_sym (RH shows LH flipped anat and BOLD data). As you can 
>>> see, agreement is generally high, but there are also marked 
>>> differences, most notably in postcentral/precentral regions.
>>> 
>>> The bottom left shows this output resampled onto the individual 
>>> surface (for comparison purposes for the next analysis).
>>> 
>>> The top right image shows the output when analyses were performed on 
>>> the individual surfaces of the original and flipped subject. Here, 
>>> agreement seems much higher, also in postcentral/precentral regions 
>>> (although still not symmetrical). The bottom right image shows this 
>>> output resampled onto fsaverage_sym, and agreement remains very high.
>>> 
>>> So it seems that performing the analysis on fsaverage_sym itself may 
>>> be affecting the expected symmetry of the output. Originally I aimed 
>>> to perform a comparison of the vectors of B-values in order to prove 
>>> symmetry, although I am not sure whether this is a viable option 
>>> anymore. Do you have any advice as to how I could proceed with this?
>>> 
>>> Finally, it appears that also in the fsaverage_sym template the L/R 
>>> vertices do not correspond to one another. So will it be possible to 
>>> flip the analysis values and template in order to perform LH v RH 
>>> comparisons at the group level?
>>> 
>>> System: Linux CentOS 6 x86_64 (64b) stable v5.3.0
>>> 
>>> Thank you for your time
>>> 
>>> James
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> Freesurfer mailing list
>>> [email protected]
>>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
>> 
>> 
>> 
>> 
>> _______________________________________________
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> 
> -- 
> Douglas N. Greve, Ph.D.
> MGH-NMR Center
> [email protected]
> Phone Number: 617-724-2358
> Fax: 617-726-7422
> 
> Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
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> www.nmr.mgh.harvard.edu/facility/filedrop/index.html
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> 
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