IMHO, after spatial normalization, John’s key contribution to SPM is spm_orthviews, the function behind the ‘Check Reg’ button which let’s you view many volumes simeltaneously. Some of the Gems use spm_orthviews (e.g. Gems 1 and 16) but listed here are some generally useful tricks for spm_orthviews.

These tricks are usefulanytimea three-view orthogonal slice view is shown, whether from useing ‘Check Reg’, ‘Display’ or when overlaying blobs from the ‘Results’ window.

Turn off/on cross-hairs

spm_orthviews('Xhairs','off')

spm_orthviews('Xhairs','on')
.

Return current x,y,z world space, mm location

spm_orthviews('pos')'

(Note that I transpose the returned value into a row vector, for easier copying and pasting.)

Move to x,y,z world space, mm location

spm_orthviews('reposition',[x y z])