Hi,

I coincidentally encountered a potential artifact when examining TSNR maps. It is a grid-like pattern that is most prominent in the axial and sagittal planes. After some investigating I've discovered that the artifact appears only after aligning the functional to the anatomical data (and is subsequently blurred after spatial smoothing).

I can just use the default anat2epi alignment instead, but I wonder what is going on. There seems to be a similar (but less severe) artifact from warping to standard space.

In case it helps, I used the following command to generate the processing script:

afni_proc.py
-subj_id $subj
-anat_has_skull no
-bash
-blocks align volreg blur mask scale regress
-copy_anat $adir/$subj/ANAT/$anat_name+orig
-dsets $adir/$subj/$prefx?+orig.HEAD
-move_preproc_files
-align_opts_aea -giant_move
-volreg_align_e2a
…

Thanks in advance for any help!

Becky