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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:
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
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
| February 05, 2014 11:44AM | |
This is basically a continuation of this thread:
[afni.nimh.nih.gov]
But my questions are more general. As far as I understand the only reasonable way to perform a group analysis of 3dNLfim statistical outputs is to do a multivariate test with 3dMVM. It wouldn't make sense to put all the parameters of a nonlinear equation (a^b-c or something) in an ANOVA model where they would be incorrectly modeled (as y=ax1+bx2+cx3), right?
Here is a picture of the same group dataset analyzed with 3dMVM:
the left is done with cspline (7 parameters), the middle one with SPMG3 (3 parmeters) the right one with 4-half cosine model (7parameters).
I am not sure if these maps (all unthresholded F-values with maximum of colorbar set to F>40) are really comparable.
Aren't the F-values dependent on the number of model parameters as well as the number of subjects?
Is there some way to normalize F-maps so that they are independent of these degrees of freedom?
[afni.nimh.nih.gov]
But my questions are more general. As far as I understand the only reasonable way to perform a group analysis of 3dNLfim statistical outputs is to do a multivariate test with 3dMVM. It wouldn't make sense to put all the parameters of a nonlinear equation (a^b-c or something) in an ANOVA model where they would be incorrectly modeled (as y=ax1+bx2+cx3), right?
Here is a picture of the same group dataset analyzed with 3dMVM:
the left is done with cspline (7 parameters), the middle one with SPMG3 (3 parmeters) the right one with 4-half cosine model (7parameters).
I am not sure if these maps (all unthresholded F-values with maximum of colorbar set to F>40) are really comparable.
Aren't the F-values dependent on the number of model parameters as well as the number of subjects?
Is there some way to normalize F-maps so that they are independent of these degrees of freedom?
| Subject | Author | Posted |
|---|---|---|
|
paranoidandroid | February 05, 2014 11:44AM |
|
gang | February 05, 2014 01:26PM |
