Hello,

I'm doing regression analyses with cortical thickness at the level of voxel. Should I correct the total GM volume by introducing this parameter as a confounding variable? Shoud I include the intracranial volume as an additional nuisance variable?  If positive, I assume that these variables can only be introduced as covariates if they differ between groups. Am I correct?

I saw in one message that we should not corret for thickness. Why not?

                                            Thanks in advance and best regards,
                                                                      Kelly