PowerPoint Presentation - Group Analysis with AFNI

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¥ STEP 3B: Create a voxel-by-voxel mean for each timeseries dataset with

3dTstat

GFor each voxel, add the intensity values of the 136 time points and divide by 136

GThe resulting mean will be inserted into the ÒBÓ slot of our percent signal change equation (A/B*100%)

foreach run (1 2 3 4 5 6 7 8 9 10)

3dTstat -prefix mean_r{$run} \

ED_r{$run}_vr_bl+orig

end

åUnless otherwise specified, the default statistic for 3dTstat is to compute a voxel-by-voxel mean

íOther statistics run by 3dTstat include a voxel-by-voxel standard deviation, slope, median, etcÉ