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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:
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
| May 07, 2015 06:37PM | |
Thanks for the quick reply Gang!
I should have specified that it is the shape of the hemodynamic response I'm trying to get, so 3dttest++ doesn't seem appropriate.
I don't mind phase being correlated with my regressors. The idea is to implement Menon's phase regression method (Ravi Menon, Mag Res Med 2002) in a slightly different way. Since phase correlates with magnitude (and therefore with the regressors of interest) in and around large veins, but not in the brain tissue, regressing phase time series from the magnitude time series should remove most of vein-borned signal. And since it is the shape of the (large vein signal-free) magnitude response I want to get, I don't mind issues of degrees of freedom.
I could always regress out phase with 3dTproject before extracting the hemodynamic response from magnitude with 3dDeconvolve, but I'm afraid that would over-correct for vein signal even more than if I do it in a single step.
I hope this makes my goal clearer.
Thanks again for the help
Sébastien Proulx
I should have specified that it is the shape of the hemodynamic response I'm trying to get, so 3dttest++ doesn't seem appropriate.
I don't mind phase being correlated with my regressors. The idea is to implement Menon's phase regression method (Ravi Menon, Mag Res Med 2002) in a slightly different way. Since phase correlates with magnitude (and therefore with the regressors of interest) in and around large veins, but not in the brain tissue, regressing phase time series from the magnitude time series should remove most of vein-borned signal. And since it is the shape of the (large vein signal-free) magnitude response I want to get, I don't mind issues of degrees of freedom.
I could always regress out phase with 3dTproject before extracting the hemodynamic response from magnitude with 3dDeconvolve, but I'm afraid that would over-correct for vein signal even more than if I do it in a single step.
I hope this makes my goal clearer.
Thanks again for the help
Sébastien Proulx
| Subject | Author | Posted |
|---|---|---|
|
Sébastien Proulx | May 07, 2015 02:46PM |
|
gang | May 07, 2015 04:07PM |
|
Sébastien Proulx | May 07, 2015 06:37PM |
|
gang | May 08, 2015 05:04PM |
|
Sébastien Proulx | May 14, 2015 07:39PM |
