Hi Yune
> I'm having trouble creating con images and I suspect this may have
> something to do with the identical design matrix across runs.
> So, in my study, I have four runs of visual conditions followed by four
> runs of auditory conditions. (They were collected on separate days, but
> were combined for multi-modal analysis) The order of contrast values are
> exactly identical across runs (e.g., 1, 1, 0, 0 (run1), 1,1,0,0 (run2)
> ..-1-1,0,0 (run7), -1,-1, 0,0 (run8).
> Is there any way to resolve this 'invalid contrast' issue?
From what you describe I can't see any problem with your design matrix
(unless I'm missing something)—it's common to have the same design
across different sessions.
Can you send a picture of your design matrix? Any chance the problem
is something like not specifying the correct number of values (one per
column)?
Jonathan
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