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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Paul Hamilton
January 21, 2009 10:30PM
Greetings All,

We're interested in estimating condition-specific IRF duration in an event-related paradigm. We've been running 3dTstat with the -duration option on IRFs rendered from 3dDeconvolve with the -iresp option. We're wondering if we might estimate something similar with the new duration modulation feature in 3dDeconvolve. Perhaps something like...

3dDeconvolve -input 3dplustime+orig -num_stimts 2 \
-stim_times_AM 1 cond1.1D 'dmBLOCK' -stim_label 1 'cond1' \
-stim_times_AM 2 cond2.1D 'dmBLOCK' -stim_label 2 'cond2' \
-gltsym 'SYM: +cond1 -cond2' -glt_label 1 'cond1 - cond2' \

cond1.1D = 4:12 18:12 30:12 ...
cond2.1D = 12:12 40:12 56:12 ...

I've used a constant duration value of 12 here (approx the duration of the HRF). Seems that the resulting duration betas would be some linear deformation of this "basis value" that would approximate IRF duration. Close at all? Your compassionately authoritative guidance will not go unheeded.

Best,

Paul
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Subject Author Posted

3dDeconvolve - duration modulation

Bob Cox December 08, 2008 12:14PM

Re: 3dDeconvolve - duration modulation

rick reynolds December 08, 2008 12:33PM

Re: 3dDeconvolve - duration modulation

Bob Cox December 08, 2008 02:41PM

Re: 3dDeconvolve - duration modulation

Paul Hamilton January 21, 2009 10:30PM