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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September 05, 2022 12:27PM
Ciao, Paulo!

We must now switch to English, or the conversation would end because I shamefully do not speak Italian. I have to ask you one day where you learned Italian.

Exactly. When I do seed-based functional correlations for one region:
1) I take a region and calculate its mean time series
2) I plop that out to a separate file for later use
3) Only then do I perform spatial smoothing as the final "preprocessing" step
4) Then I take my outputted file and use it to do the correlations

That is my conundrum. I must not do spatial smoothing before calculating the mean time series. And I must do it afterwards and immediately prior to using the calculated mean time series in the correlations. However, the sublime convenience of 3dNetCorr creates a paradox because it performs everything in a single step. Maybe that is just the reality: the convenience of 3dNetCorr may preclude spatial smoothing because everything is done in a single step.

This is gnawing at me a lot lately. Because, the spatial smoothing not only gives us some critical statistical niceness. It obviates the problem of residual geometric distortion present in all fMRI studies if you did not collect a phase image, which I did not collect for later use with epi_b0_correct.py, if the spatial smoothing that you plan to do anyway is larger than the distortion.

Sincerely,

Dante
Subject Author Posted

Blurring and 3dNetCorr

dante.picchioni September 04, 2022 02:13PM

Re: Blurring and 3dNetCorr

ptaylor September 04, 2022 03:34PM

Re: Blurring and 3dNetCorr

dante.picchioni September 05, 2022 12:27PM

Re: Blurring and 3dNetCorr

ptaylor September 05, 2022 06:43PM

Re: Blurring and 3dNetCorr

dante.picchioni September 06, 2022 09:33AM