> I'm wondering if anyone has the coordinates for the posterior commissure
> of T1.img or single_subj_T1.img.
You might want to have a look at:
http://www.mrc-cbu.cam.ac.uk/Imaging/antcomm.html
I guess the coordinates that I estimated for the PC on Colin Holmes' brain were:
X 0, Y -24 and Z -3 mm
The PC is very difficult to make out on the average brain.
> Also, just to clarify: T1.img is the SPM96 template, which is Colin
> Holmes' brain, which is registered to the MNI avg brain with a 9-parameter
> affine?
Well, no; have a look at the SPM help pages on the templates; there is an html
version of that at:
http://www.mrc-cbu.cam.ac.uk/Imaging/templates.html
The T1.img is a 8mm smoothed version of the MNI 152 average brain.
> And single_subj_T1.img is the individual brain that looks the
> most like the MNI average? Are both brains suitably representative of the
> MNI brain for purposes of plotting and rendering?
single_subj_T1.img is Colin Holmes' brain; I don't think the MNI have ever
suggested that Colin's brain was the most typical, it's just that they had lots
of scans for him, so it has good detail after averaging. Personally I would
use the ag152t1.img in the SPM canonical directory for plotting and rendering,
which is the unsmoothed version of T1.img. The individual brain can give a
rather false sense of the anatomical specificity of normalized results.
Best,
Matthew
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