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  

Previous Message Next Message
Message List New Topic Print View
|
nic
January 05, 2014 01:53PM
Hi everyone,

I am using 3ddelay to estimate the BOLD delay for blocks of breath holding (compared to rest).

The preprocessing pipeline follows these steps in order: time-shifting, volume registration, tlrc'ing, mean scaling, and detrending of the data (no spatial smoothing).

I did analyses with three different wave forms (square wave, a gamma variate, and waver; cmds below) as some investigators for instance use a gamma variate and others use a square wave. My analyses produce somewhat different results and I'm wondering which wave form is most appropriately used in 3ddelay?

Thank you very much!

Nic


1) 0s & 1s for the square wave
2) 3dDeconvolve -nodata 115 2.5 -polort -1 -num_stimts 1 -stim_times 1 '1D: 3 51 99 147 195 243' 'GAM(8.6,.547,15)' -stim_label 1 gam.dur -x1D gam.1D
3) 3dDeconvolve -nodata 115 2.5 -polort -1 -num_stimts 1 -stim_times 1 '1D: 3 51 99 147 195 243' 'WAV(15,0,4,6,0,0)' -stim_label 1 wav_ideal -x1D wav.1D
Reply Quote
RSS
Subject Author Posted

reference time series for 3ddelay

nic January 05, 2014 01:53PM

Re: reference time series for 3ddelay

ziad January 06, 2014 10:07AM