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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
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The problem exist in the group analysis. I checked the iresp of several individual subjects and it is not just below average but also a negative-going response (i.e., betas going below baseline and then back up to baseline).
I used the general mean (across subjects and conditions). Would it make sense to use across-subjects means for each condition separately? My initial problem was large reacti
by
kallai
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AFNI Message Board
Thanks for this idea.
I used the mean RT of all subjects in all conditions. Do you have an idea whether it is reasonable that following this manipulation the HDR was reversed and from positive it became negative? I have a hard time understanding this.
In the modulation sub-brick [#1] the betas are usually highly positive, but in the modulated sub-brick [#0] they are negative in regions I expect
by
kallai
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AFNI Message Board
Thank you very much for your reply, Gang!
I have a followup question: if I understand the AM2 analysis correctly, then the controlling for RT is within each condition but not between conditions. This explains the fact that the controlled-for-RT sub-brick (i.e., [#0]) is so similar to the analysis without modulation.
Given that I am worried about differences BETWEEN conditions, is there a better
by
kallai
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AFNI Message Board
Hello Afni experts!
I inherited some data that has several problems. One of them is that the four experimental conditions led to very different reaction times (ranging between 1.2 and 3.7 sec, for the conditions averages). Thus, RT is a confound of the experimental conditions and might stand in the basis of any significant difference between them.
I would like to see if there are differences
by
kallai
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AFNI Message Board