#10 MNI coordinates for defining spherical roi?
I have been trying to define a spherical roi using roi
toolbox (v2.0).
What I found was that I should use specific MNI
coordinates to accomplish this. Otherwise the program
give an error message " the location is not on the grid."
For example, -20, 4, -20 wouldn't work, but -21, 6, -21
works.
Someone in the spm mailing list pointed out that this is
related to the fractional voxel coordinates that given
MNI coordinates may result in and suggested to modify
the MNI coodinates to make sure that the resulting
voxel coordinates being round numbers (see
http://www.jiscmail.ac.uk/cgi-bin/wa.exe?
A2=ind0210&L=spm&P=R7557&I=-1).
Although this suggested solution worked good, I also
wonder whether there is a way to solve this problem
without modifying the original MNI coordinates.
Thanks for your time and help.
Sincerely,
Sanghee Kim
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user_id=95076
hi - my guess is that there probably is a way to do this, but I've
not explored it.
also - if you could send me your version of the spherical roi
program that fixes the problem I would greatly appreciate it.
cheers
russ poldrack
poldrack@ucla.edu