Hello,
In order to derive the temporal course of a ROI I follow these steps
1) Draw an spherical ROI using fslmaths,
(e.g.)
fslmaths /usr/local/fsl/data/standard/MNI152_T1_2mm_brain.nii.gz -mul 0 -add 1 -roi 32 1 68 1 29 1 0 1 -kernel sphere 3 -fmean rOFC -odt float
2) Use featquery to derive the temporal course for each individual subject in the relevant COPE
by using the mask output in step 1)using the output
In featquery I select - DO NOT binarise mask (allow weighting)......
the thing is that if I don't select the DO NOT Binarise then the temporal course file contains only zeros
is this OK?
On a related note, I also use featquery to derive the % signal change for each individual subject
based on the cluster_mask_zstat at the highest level....I think that selecting DO NOT Binarise mask may be problematic here
becos the cluster_mask_zstat's variation in the z values will be weighted in the extraction of the % signal change for each individual subject..which does not seem right.
I would appreciate to hear from you what is the role of using DO NOT binarise mask (allow weighting) and when should be used and when not- which by the way in one of the FSL feat practicals it is said to use it!
http://www.fmrib.ox.ac.uk/fslcourse/lectures/practicals/feat1/index.htm
Cheers, David
|