we have performed a VBM
analysis with 4 groups (3 with different grade of pathology and 1
healthy control group). We carried out an ANOVA between 4 groups with no
covariates given that there were no significant differences between groups regarding variables which could affect gray matter volume (TIV, Age, Gender, Schooling..).
Even though, reviewers have suggested us to include TIV and Age as covariates, would it be correct? in case of including them, would they act as a confounding agent, introducing noise to the analysis?
Thank you in advance for the help.
-- Maria Serra
PIC (Port d'Informació Científica) Campus UAB, Edifici D
E-08193 Bellaterra, Barcelona Telf. +34 93 586 8232 www.pic.es
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