Dear SPM users,
I want to find out which part of the brain activation is more correlated with a behavioral skill in group 1 and in group 2 separately.
My behavioral skill is a score from 0 to the infinite (gamma distribution) better is the subject lower is the score.
I want to use a multiple regression analysis in SPM12 but I am not quite sure how to do this. I am confused about how to use some parameters :
factorial design specification > Design : Multiple regression
* Covariate > Centering or no centering? What is the difference between both and in which case should I use either ?
* Intercept > Include Intercept or omit intercept? What is the difference between both and in which case should I use either ?
Thank you in advance for your help
Best regards
Caroline
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