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

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Michael
November 18, 2009 04:51PM
Hi Gang,
I ran a one-sample t-test vs 0 with the beta from the GLT of A-B and also ran a separate paired t-test with the betas from A and B as set2 and set1 respectively. The output is not the same. When I look at the data in AFNI, I see that the ranges for OLay and Thr are different

For the one-sample t-test on the GLT, the ranges are
OLay -9.136437 : 3.910597
Thr -5.680815 : 4.477454

For the paired t-test on the individual betas, the ranges are:
OLay -9.136297 : 3.909143
Thr -5.673052 : 4.51635

The overlay images are actually very similar, but at higher thresholds, see differences between the two maps (usually on the order of stray voxels). Nonetheless, I was expecting the maps to be identical.

Any thoughts?
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Subject Author Posted

GLT versus t-tests

michael November 17, 2009 09:57PM

Re: GLT versus t-tests

Gang Chen November 18, 2009 12:23PM

Re: GLT versus t-tests

Michael November 18, 2009 02:11PM

Re: GLT versus t-tests

Michael November 18, 2009 04:51PM

Re: GLT versus t-tests

rick reynolds November 18, 2009 06:09PM