Dear all,
I specified a second level analysis using a paired t-test design to assess differences in BOLD signal between two experimental conditions. So for every participant (nsubs=31) I have a pair of nifti files. However I`m not sure at all whether I defined my contrasts correctly.
For the direct comparison between both conditions (condition1 > conditions2) I tried the following:
matlabbatch{3}.spm.stats.con.consess{1}.tcon.name = 'Ons_cond1>Ons_cond2' ;
matlabbatch{3}.spm.stats.con.consess{1}.tcon.weights = [zeros(1,nsubs) 1 -1];
matlabbatch{3}.spm.stats.con.consess{1}.tcon.sessrep = 'none';
This seems to work out fine but, I was wondering if its also possible to assess the mean BOLD across both condtions. Here I tried the following
matlabbatch{3}.spm.stats.con.consess{2}.tcon.name = 'Mean(Ons_cond1, Ons_cond2)' ;
matlabbatch{3}.spm.stats.con.consess{2}.tcon.weights = [zeros(1,nsubs) 1 1];
matlabbatch{3}.spm.stats.con.consess{2}.tcon.sessrep = 'none';
However this does not seem to work out, as SPM through an error.
Any help would be appreciated, also please let me know if you need more information. Thanks in advance!
Kilian
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