Differentiating between Masked Voxels in Graph Viewer

Hi All,

Apologies in advance for the simple question:

Sometimes I am able to see which voxels are masked (white background) and which voxels are not in my mask (gray background). I can’t seem to figure out why sometimes it works and sometimes (now) I can not get the mask I have created to do this operation in the AFNI graph vieer. I created my mask in matlab, saved as nifti, and then re-saved as BRIK in AFNI. Any insight into how to toggle this function would be greatly appreciated.

Thank you!

The gray graphs are below threshold in the overlay.


There is an AFNI environment variable to set for this behavior:

If this variable is set to YES, then the 'threshold fade' feature
of the AFNI graph window is turned on for all graph viewers when
they open. Otherwise, you have to turn this feature on via the
'F' key or the toggle control in the Opt menu.

So, you can put a line like this in your ~/.afnirc file to set it whenever you open up afni:


To get this functionality, I think you need to have both 1) an olay (overlay) dataset selected, and 2) a nonzero threshold set.

Even if your mask is set and loaded as an olay, if condition #2 is not set, you won’t get the white/gray differentiation in the graph viewer.

That all being said, this wasn’t working on my laptop at the moment (with the latest version of AFNI), so it might be that something is a-broken at the moment. Will investigate a bit more next week.