-16-
¥ STEP 3C: Calculate a voxel-by-voxel percent signal change with         3dcalc
G
GTake the 136 intensity values within each voxel, divide each one by the mean intensity value for that voxel (that we calculated in Step 3B), and multiply by 100 to get a percent signal change at each timepoint
GThis is where the A/B*100 equation comes into play
G
å foreach run (1 2 3 4 5 6 7 8 9 10)
å 3dcalc -a ED_r{$run}_vr_bl+orig \
å -b mean_r{$run}+orig   \
å -c full_mask+orig   \
å -expr Ò(a/b * 100) * cÓ  \
å -prefix scaled_r{$run}
å end
å
åOutput of 3dcalc: 10 normalized datasets for Subject ED, where the signal intensity value at each timepoint has now been replaced with a percent signal change value
å scaled_r1+orig, scaled_r2+orig É scaled_r10+orig