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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December 09, 2002 12:40PM
Hi all

I am doing a region of interest analysis: I extract the average signal from each ROI and import it (to excel). Before calculating the correlation with my reference waveform, I would like to detrend the signal the same way FIM+ (and Fbuc I guess) does and I wonder what the best way would be and how to do it exactly:
- Should I detrend the average signal from the ROIs using 3dDeconvolve? To do that, is such a command the right way to do it? :
3dDeconvolve -input1D ROI_average.1D -num_stimts 0
- Or should I detrend the BRIK before extracting the average ROI signal using 3dDeconvolve or 3dDetrend?
I tried to use 3dDetrend but got confused about which –expr to use. I have tried -expr '1' -expr 't' -expr 't*t', which is supposed to remove a quadratic trend from the data but is that what Fim+ does?
Is the command for using 3dDeconvolve something like that?
3dDeconvolve –input subject_3d+time.BRIK –num_stimts 0
Or maybe there is still another way that would be better?
Any advice will be greatly welcome. Thanks a lot!

Barbara
Subject Author Posted

detrend signal from ROI

Barbara Cerf-Ducastel December 09, 2002 12:40PM

Re: detrend signal from ROI

B. Douglas Ward December 09, 2002 04:14PM

Thanks!

Barbara Cerf-Ducastel December 09, 2002 05:06PM