RE: How to define "site" as covariate

Hi, I am also looking for answer on how to properly control for multiple sites in the contrast manager.

Currently I have 5 sites and have dummy coded them as 5 separate variables.


If I want to do an resting state ancova controlling for age, sex, sites would it look like this?

Group Covariate Age Sex Site1 Site2 Site3 Site4 Site5

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[i]Originally posted by Ali Amad:[/i][quote]Dear Conn users, dear Alfonso,

I am currently analysing rs-fMRI from 3 different sites (scan from different manufacturers but all with exactly the same scan parameters). I have some troubles to correct for the site effect by using conn.
I have read the post suggesting that GCOR could be used when comparing subjects across different sites and I have some questions :

1) Is there any other way to correct the site effect by using categorical 2nd level covariates ?

2) If I use GCOR, should I just add this covariate in the denoising step ? Is there any reference that can be cited to justify this method ?

Many thanks in advance for your help,

Best wishes,

Ali[/quote]