Hello AFNI experts,

After analyzing a dataset in AFNI, we decided to analyze it also in SPM, since it appeared that the motion correction parameters (given by the .1D files from 3dvolreg) were somehow underweighted. When running the realign & unwarp step in SPM, the motion parameters given in the .ps file did appear to be much greater.

However, when I concatenated the rotation parameter files from a single subject in SPM and viewed them in 1dplot, it looked very similar to the AFNI motion correction plot (see attachments for comparison).

My question is whether there is some sort of scaling issue I am overlooking in 1dplot. Also, which of the columns in the 1D files correspond to which movement parameter? (I would like to compare the scaling differences in the 1D files between AFNI and SPM).

Thank you,

-Andrew