Hello Afni experts!
I inherited some data that has several problems. One of them is that the four experimental conditions led to very different reaction times (ranging between 1.2 and 3.7 sec, for the conditions averages). Thus, RT is a confound of the experimental conditions and might stand in the basis of any significant difference between them.
I would like to see if there are differences between conditions beyond the RT differences, so I tried to include RT as a modulator variable in stim_times_AM2. However, I am not sure which output should I consider if I am looking for the effect after regressing out the RT effect. The first sub-brick [#0] seems to be identical to an analysis of stim_times without the AM2. Does it mean that the second sub-brick [#1] is the effect after regressing the RT out? If not - is there another way I can control for different RTs?
Thank you very much in advance!
kallai.