Hello all,
I have been carrying out some featquery analyses on some data. I have
noticed that when I run featquery on data averaged over two runs of a task
(each participants gfeat) the number of non-zero voxels in the output report
seems to be exactly the same for all participants for the PE, COPE, Tstat and
Zstat. Very rarely there is a participant where the number of non-zero voxels
differs from all the rest of the participants. It only differs between the
participants for the thresholded z stat. However when I run featquery on
each of the individual runs of the task not only do I get values for mean %
signal change that do not average to give the means I get when I run the
analyses on the gfeats but the number of non-zero voxels differs quite a lot
between participants for the PE, COPE, Tstat and Zstat.
I wondered if anyone could explain why this is and if I am doing something
wrong.
Many many thanks
Jess
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