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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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Results 61 - 67 of 67
Dear Gang,
I think we are on the same page now. Thanks for sticking with me.
I understand what you are saying about the difficulty cause by the coding -1, 0, and 1. You are saying that my "linear regression" is really just a t-test between conditions 1 and 3. Is that right?
I should mention that I turned 3dRegAna into a within-subjects regression by adding 15 vectors, one for
by
Christine Smith
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AFNI Message Board
Hi Gang,
It occurred to me, after writing my previous post, that you might think I am trying to run 3dRegAna on an individual subject. I normally calculate the "area under the curve" measures for each of the three conditions from each subject. Next, I enter those data from all 15 participants into 3dRegAna and look for a linear trend in the 'area under the curve' measures a
by
Christine Smith
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AFNI Message Board
Dear Gang,
Thanks for taking the time to answers my questions. It looks like this question is not a simple one to answer.
I am still using the 'old' approach and am not taking advantage of the new TENT type functions as of yet. These data are several years old, and I don't want to redo all the analyses. Apologies.
You wrote: "3dRegAna would not work properly in this
by
Christine Smith
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AFNI Message Board
Hi Gang,
I code the vectors as a time series of 1s and 0s and then let 3dDeconvolve figure out the IRESP via min and maxlag. I do not preconvolve the vectors.
I like the idea of 3dMEMA, but I don't see an example where I could test for a linear trend in my 3 conditions. I would normally use 3dRegAna coding the three conditions with 1, 2, and 3. I don't see an equivalent way to do
by
Christine Smith
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AFNI Message Board
Hello,
I normally use 3dDeconvolve to extract the beta weights of my variables of interest. For example, I code three different vectors with 1s where conditions 1, 2 or 3 occurred. Then I extract the beta weights for conditions 1, 2, and 3 and submit them to a group-level parametric analysis.
The problem is that a couple of my subjects do not have enough trials in one of the conditions to
by
Christine Smith
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AFNI Message Board
Super! Thanks for getting back to me Peter. I will give that a shot.
Best,
Christine
by
Christine Smith
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AFNI Message Board
Hello,
I am wondering how to obtain an amplitude measure for each trial of an experiment. I normally use 3dDeconvolve to average together the HRFs from many trials of the same type. In that case, I use 20-30 trials to get an estimate of the brain activity amplitude for a particular trial type.
Now, I would like to get a measure of brain activity amplitude for each trial. My end goal is to
by
Christine Smith
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AFNI Message Board
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Pages: 123