Hi Robin,
If you run tsplot from the command line you can specify a different voxel
to use with the -c option. There isn't an equivalent option for ROIs yet
(though it's on the todo list) but you could (I think) kludge this with:
make a COPY of your FEAT directory to work in, then in there:
avwstats <ROIMASKIMAGE> -v -V
then set <RATIO> to output1 divided by output3 (this will keep absolute
values the same in the next command)
foreach i ( filtered_func_data mask stats/*hdr )
avwmaths_32R $i -mas <ROIMASKIMAGE> -Xmean -Ymean -Zmean -mul <RATIO> $i
end
(this averages each image over the ROI)
/bin/rm tsplot/*
tsplot . -c 0 0 0 -o tsplot
this won't recreate the web page but all the text files and GIF images are
created in the tsplot subdir.
You're nearly right; but the PS plots are created by averaging the model
fits across epochs, not by refitting within the epochs. So the green and
blue lines are the averaged model fits, and the data isn't averaged, but
fully plotted showing its spread.
cheers :)
On Thu, 1 Apr 2004, Robin Goldman wrote:
> Hi there,
>
> Is it possible to get peri-stimulus plots for an ROI? Or for a voxel other than the peak voxel?
>
> And let me make sure I understand what you have done to get the peri-stimulus plots. You have
> taken the data time course for the peak voxel in a given contrast and plotted this time course
> broken up into "epochs," where the start time for each of these epochs is defined by the event
> timing given in each EV. So, one plot per EV. You then fit these points to get an estimate of the
> response shape at that voxel for that event type. Is this right? Not quite, I think, or you'd call it a
> "data fit" instead of a "full model fit"... And I assume the EV model fit is the same in the data and
> reduced data plots, yes?
>
> And one more question -- how do you model the data to get a resolution of 1 second?
>
> Thanks!
> Robin
>
Stephen M. Smith DPhil
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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