I would suggest that you run FSL's MELODIC ICA tool on the dataset to
get a better feel for where the signal is coming from time-wise.
cheers
russ
On Mar 8, 2005, at 8:23 AM, SALGADO PINEDA Pilar wrote:
>
>
> Dears SPM's
>
> We are working with an fMRI paradigm (two tasks, “activation” and
> “control”) that seems to have worked very well with the currently
> evaluated subjects. Nevertheless we have found a subject where
> activation exceeds the imaginable (nearly all the gray substance),
> although the movement parameters did not exceed 3 mm /3 degrees in
> each axis.
>
> Using the motion parameters like covariate in the statistical design
> does not solve this problem.
>
> Any explanation?
>
> Could it be due to a physiological variable that correlates with the
> task presentation, only in this subject? … and are there some matlab
> routines that can be used with spm2 to evaluate the possible presence
> of significant correlations between the global brain mean and the
> tasks conditions (to decide the use or not of Global Scaling)?
>
>
>
> It is possible to use of the Global Scaling correction only for a
> subject in a design group?
>
>
>
> Thanks for any help,
>
>
>
> Pilar
>
---
Russell A. Poldrack, Ph.D.
Assistant Professor of Psychology, UCLA
Franz Hall, Box 951563
Los Angeles, CA 90095-1563
email: [log in to unmask]
phone: 310.794.1224
fax: 310.206.5895
web: http://www.poldracklab.org/
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