Dear Marie,I want to run a group analysis on a set of subjects, correcting for gender(Male/Female), diagnois regarding epilepsy (no focus/focus in rh/focus inlh/focus in both h), age and IQ. Should my FSGD file look somewhat like thisbelow:GroupDescriptorFile 2Class NoFocus_MaleClass NoFocus_FemaleClass RhFocus_MaleClass LhFocus_MaleClass BhFocus_MaleClass RhFocus_FemaleClass LhFocus_FemaleClass BhFocus_FemaleVariables age IQIf so, considering that I want to investigate the effect of epilepsy on corticalgyrification, what should my contrast matrix look like?The hypothesis is that the gyrification index is diminished for epilepticpatients, probably more when there is bilateral focus.I know that we need as many number as regressors, so I expect there to be 10numbers, is it so?Thank you so very much for clarifying this point,Kenza