Hi Rick,

Sorry, I should have been more clear. I was referring to the area just above the slider. I checked both sub-bricks but the "?" is present for both. Here is the output of 3dinfo:

Number of values stored at each pixel = 2
-- At sub-brick #0 '?' datum type is float: -1.1907 to 0.826943
-- At sub-brick #1 '?' datum type is float: -5.16984 to 3.47787

The value ranges seem to make sense but I'm trying to compare an interaction effect from 3dRegAna to a double-subtraction t-test and am getting different results so I wanted to see if something was going wrong with the ttest.

Thanks for your help.

Jatin