Making contrasts outside of 3dDeconvolve

AFNI Message Board
1

Hello,

I have 6 correlation maps and I am looking for a way to perform a contrast on them (the same way you would make contrasts of beta weights in 3dDeconvolve). The intent is to run these contrasts on seed correlation maps, as opposed to beta maps that are outputted by 3dDeconvolve.

Example below:

+0.5 A
+0.5 B
-0.25 a
-0.25 b
-0.25 c
-0.25 d

Is there a way to perform “gltsym” or something similar without using 3dDeconvolve or 3dREMLfit?

2

A simple weighted sum can be computed with 3dcalc, but
it will not come with any significance statistic like
3dDeconcolve would output. Using the A,B,a,b,c,d as
labels in 6 different datasets, consider:

3dcalc -a corr_A+tlrc -b corr_B+tlrc -c corr_a+tlrc \
       -d corr_b+tlrc -e corr_c+tlrc -c corr_d+tlrc \
       -expr '0.5*(B+A)-0.25*(a+b+c+d)' -prefix corr_contrast

Note: A+B is reversed just to prevent an irritating emoji…

  • rick
3

Thank you very much!