Hi Erika,
 
Many thanks for the explanation. I will definitely look into afni_proc.py for further processing.
But what I am looking right now is a process that can perform motion corr and slice timing correction simultaneously (in a single process). From what I read from afni-proc.py help, yes it does motion-corr and slice timing corr, but they are two different process, e.g. slice-timing correction first, then motion correction or vice versa.
CMIIW