-13-
GNow letÕs take those 10 masks (we donÕt need 10 separate masks) and combine them to make one master or Òfull maskÓ, which will be used to calculate the percent signal change only for values inside the mask (i.e., inside the brain).
G3dcalc -- one of the most versatile AFNI programs -- is used to combine the 10 masks into one:
G
G 3dcalc -a mask_r1+orig -b mask_r2+orig -c mask_r3+orig \
G -d mask_r4+orig -e mask_r5+orig -f mask_r6+orig \
G -g mask_r7+orig -h mask_r8+orig -i mask_r9+orig \
G -k mask_r10+orig    \
G -expr Ôstep(a+b+c+d+e+f+g+h+i+j)Õ    \
G -prefix full_mask
G
åOutput: full_mask+orig:
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