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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Gang Chen
February 27, 2009 01:30PM
> I'm curious if the coefficient from sub-brick 0 in spmg3 can be treated as a
> percentage change value as I would have done for the GAM-based coefficient.

No, the SPMG3 basis functions are not normalized, and they don't have a peak of 1. You can check them out by running the following two commands:

3dDeconvolve -nodata 300 0.1 -polort -1 -num_stimts 1 -stim_times 1 '1D: 0' SPMG3 -x1D spmg3
1dplot -one spmg3.xmat.1D &

So you may have to scale your original beta values by ~6 before you could interpret them as percent signal changes.

HTH,
Gang
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Subject Author Posted

Basis Functions Clarification

Jatin February 27, 2009 10:38AM

Re: Basis Functions Clarification

Gang Chen February 27, 2009 01:30PM