Dear SPMers
I have a query regarding my matrix design using a 2*3 factorial design. The study has two sessions with each session repeating the exact task but using different stimuli. To avoid issues of sphericity I have concatenated session 1 and 2 at preprocessing stage.
My fMRI task includes 2 tasks (Cognition/Emotion) 3 conditions (pictures:positive, negative and neutral). In total I enter 6 regressors: Cog_positive, Cog_negative, Cog_neutral, Emo_positive, Emo_negative, Emo_neutral.
In my first level I enter the 6 regressor above for session 1, the smoothed scans and my movement parameters for scan 1.
I repeat the same for my session 2.
I created my contrasts building on 12 regressors (being the first 6 for session 1 and the other 6 for session 2).
The problem I find is when opening the results my matrix design does not match what I was expecting. Basically each regressor for each block is triplicated, so three times cog_positive and so on for the other regressors.
Would anyone have advice of what could be going wrong?
Thank you,
Pablo
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