By default AFNI uses RAI coordinates. When you click on the image and say "Jump to XYZ", you may notice that it says "RAI" in the top of that window. You can change to "SPM" or LPI coordinates by right clicking on the upper left side of the controller window (where it says "order: RAI=DICOM") and selecting LPI. Then your jump to command will say "LPI" and your coordinates will put you in the L STG.
Happy Mapping!