You did not create the contrast matrix correctly. There needs to be a column for each subject, then a column for time point1 and one for time point 2. Use DOSS (defaults to DODS). Also, I think you could compute tp2-tp1 if you wanted to (makes things easier).

On 12/14/2021 5:58 PM, stdp82@virgilio.it wrote:

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*Hi list,*

*I have two groups undergoing two different treatments: one's placebo , one's drug. Two timepoints, at baseline (T1, no treatment) and at treatment (T2). 2x2 ANOVA, repeted measures has been applied by following the guidlines and mailing list.*

*IMPORTANTLY, to compute tp2-tp1, as reported in the fsgd example, is not an option to be done because we aiming to assess the interaction between time and treatment.*

*Please chech the design matrix, the command line produces an error.*

*GroupDescriptorFile 1* *Title 2x2_repeted_measures* *Class Subject1 * *Class Subject2 * *Class Subject3 * *Class Subject4 * *Class Subject5 * *Class Subject6 * *Class Subject7 * *Class Subject8 * *Class Subject9 * *Class Subject10* *Class Subject11* *Class Subject12* *Class Subject13* *Class Subject14* *Class Subject15* *Class Subject16* *Class Subject17* *Class Subject18* *Class Subject19* *Class Subject20* *Class Subject21* *Class Subject22* *Class Subject23* *Class Subject24* *Variables tp1-vs-tp2.drug tp1-vs-tp2.plb* *Input CODE01_tp1 Subject1 1 0* *Input CODE02_tp1 Subject2 1 0* *Input CODE03_tp1 Subject3 1 0* *Input CODE05_tp1 Subject4 1 0* *Input CODE06_tp1 Subject5 0 1* *Input CODE07_tp1 Subject6 0 1* *Input CODE09_tp1 Subject7 0 1* *Input CODE10_tp1 Subject8 1 0* *Input CODE11_tp1 Subject9 1 0* *Input CODE12_tp1 Subject10 0 1* *Input CODE13_tp1 Subject11 0 1* *Input CODE14_tp1 Subject12 1 0* *Input CODE15_tp1 Subject13 1 0* *Input CODE16_tp1 Subject14 1 0* *Input CODE17_tp1 Subject15 0 1* *Input CODE18_tp1 Subject16 1 0* *Input CODE19_tp1 Subject17 0 1* *Input CODE20_tp1 Subject18 0 1* *Input CODE21_tp1 Subject19 0 1* *Input CODE22_tp1 Subject20 1 0* *Input CODE23_tp1 Subject21 0 1* *Input CODE24_tp1 Subject22 0 1* *Input CODE25_tp1 Subject23 1 0* *Input CODE26_tp1 Subject24 0 1* *Input CODE01_tp2 Subject1 -1 0 * *Input CODE02_tp2 Subject2 -1 0 * *Input CODE03_tp2 Subject3 -1 0 * *Input CODE05_tp2 Subject4 -1 0 * *Input CODE06_tp2 Subject5 0 -1 * *Input CODE07_tp2 Subject6 0 -1 * *Input CODE09_tp2 Subject7 0 -1* *Input CODE10_tp2 Subject8 -1 0 * *Input CODE11_tp2 Subject9 -1 0 * *Input CODE12_tp2 Subject10 0 -1* *Input CODE13_tp2 Subject11 0 -1* *Input CODE14_tp2 Subject12 -1 0 * *Input CODE15_tp2 Subject13 -1 0 * *Input CODE16_tp2 Subject14 -1 0 * *Input CODE17_tp2 Subject15 0 -1* *Input CODE18_tp2 Subject16 -1 0 * *Input CODE19_tp2 Subject17 0 -1* *Input CODE20_tp2 Subject18 0 -1* *Input CODE21_tp2 Subject19 0 -1* *Input CODE22_tp2 Subject20 -1 0 * *Input CODE23_tp2 Subject21 0 -1* *Input CODE24_tp2 Subject22 0 -1* *Input CODE25_tp2 Subject23 -1 0 * *Input CODE26_tp2 Subject24 0 -1*

*a) groupxtime.mtx 0 0 1 -1* *b) tp1-vs-tp2.Mod.mtx 0 0 1 0* *c) tp1-vs-tp2.Plb.mtx 0 0 0 -1*

*mri_glmfit --y ces.nii.gz --wls cesvar.nii.gz --surface fsaverage rh --glmdir repeted_measures.wls --nii.gz --fsgd Repeted_measure.fsgd --C Tp1-vs-Tp2.Mod.mtx --C Tp1-vs-Tp2.Plb.mtx --C groupxtime.mtx*

*ERROR: dimension mismatch between X and contrast Tp1-vs-Tp2.Mod.mtx       X has 72 cols, C has 4 cols*

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