Hi,
In a regressor of interest, there are 10 trial repetitions. In order to see the parametric effect of a rating score during this epoch, I entered the 10 scores for each trial. However, I found that, in one subject (A), all the scores are the same (all with a score of 2). SPM8 won't allow me to perform this parametric modulation model.
Is it due to the requirement that the parametric regressor must be orthogonal to the main regressor?
Since I want to put all subjects' parametric con files for a group average map, anyone know how can I deal with the parametric con file from subject A? I guess I can use his main regressor con file instead, but not sure if I'm correct.
Thanks.
Mike
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