AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

History of AFNI updates  

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January 28, 2008 09:32AM
I got some seemingly odd results from the new 3dFDR algorithm. After flipping back and forth between the input and output dataset, I am suspicious that it is producing incorrect results. My input dataset has very few voxels set to a probability of 1 (within the masked region, the brain) and has some prounced clusters of activation (note compelling negative VMPFC, for instance). The output contains no significant voxels at any value of q that would be useful for making a statement about false discovery rate. If I run the old algorithm (-old), the output dataset includes the clusters at useful values of q. This "old" results seems to reflect the spirit of what FDR is intended to do better than the new results.

My suspicion, therefore, is that this is tripping over some bug in the implementation. Or do I miss understand what the new algorithm is trying to do?

I assumed positive regression dependency on subsets, as is default.

I would upload the input dataset in question, but the web server seems to check out when I attach it.

Best,
Brent
Subject Author Posted

New 3dFDR too conservative? (Jan 18 08 version)

Brent Field January 28, 2008 09:32AM

Re: New 3dFDR too conservative? (Jan 18 08 version)

bob cox January 28, 2008 09:39AM

Re: New 3dFDR too conservative? (Jan 18 08 version)

bob cox January 29, 2008 02:32PM