This may or may not be helpful, but, I was and still am fascinated by
grayordinates.
Alpay,
I think you are asking for a mapping from grayordinates to a standard volume
representation of the functional areas, such as MNI or Talairach coordinates. I
think Matt might be resistant because the
Matt,
thank you very much for your explanations.
Taking a pragmatic view, I just loaded the time series data from the
grayordinates file
rfMRI_REST1_LR_Atlas_hp2000_clean.dtseries.nii
picked up one of the time series and subtracted it from
all of the time series in the file
Matt,
The focus of the project is the resting state data, at this point
all of the requests are concerned about these data sets, rfMRI, no
other data sets are involved.
As you indicated in your previous e-mail, in rfMRI data
'cross-subject correspondence is maintained through having the same
Matt,
thank you for your quick reply.
Just to clarify, my original question was not implying anything
negative about the grayordinates nor any desire to work in MNI space.
In fact, in my view, grayordinates are logically addressing many space
constraints and analysis problems appropriately.
To
The whole point of grayordinates is not to work in MNI volume space, but
to work in a combined cortical surface and subcortical volume space with
better grayordiante-wise correspondence across subjects. The improvements
gained with grayordinates are simply not possible to achieve in MNI volume
Thanks Matt for your prompt and patient replies to all the questions.
Unbelievable amount and quality of your work.
What exactly do you mean by volume transformation of surface coordinates?
Was the surface generated by the anatomical images in the MNI space or the
native space?
Zhongming
Surfaces were generated in undistorted native volume space rigidly rotated
to roughly align with MNI space.
One can use affine or nonlinear warp fields to transform coordinates just
as one can transform images. It is just with coordinates one’s precision
is much higher because coordinates are
So we had a thread about this a few weeks back. Surface registration and
volume registration are two completely independent things, so long as the
surfaces are originally created in native subject space. We don’t do it
way #1 because that would require making two large volume timeseries and
we
