3dISC FDR q warning

AFNI Message Board
1

Hello,

I recently ran a very basic, one group ISC analysis on my data (58 subjects). I got the following warning:


*+ WARNING: Smallest FDR q [0  t] = 0.9999 ==> few true single voxel detections
++ Smallest FDR q [1 #1] = 4.36105e-13

I am a little confused as to what this means. What are the [0 t] and the [1 #1] referring to? When I am looking at the images in AFNI the q value stays at 0.999 no matter where I set the overlay slider, which is concerning!

Thanks!

Ryann

2

Ryann, that’s just a warning indicating that particular sub-brick would have problem gong through the FDR scrutiny. So, don’t panic.

3

Thanks for the quick reply! As I understand it, the first sub-brick is the image with the ISC correlation values, and the second sub-brick is the t-statistic map? It looks like the t-statistic map survives the FDR scrutiny… this is the one that matters when it comes to assessing statistical significance of ISC in the voxels, right?

4

It looks like the t-statistic map survives the FDR scrutiny… this is the one that matters when it comes to
assessing statistical significance of ISC in the voxels, right?

Right. So, the program might have barked up the wrong tree then. I’ll have to check it up later.