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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Cesar Caballero Gaudes
September 06, 2020 03:30AM
Hola Ana,

The error indicates that the number of nuisance regressors is larger than the number of time points after censoring. In other words, the remaining data would have -1 degrees of freedom!!

This is probably due to the combination of censoring and bandpass filtering. What is the TR of the acquisition? If the TR is too fast, bandpass filtering needs to include many, many regressors to remove all the frequencies from 0.1 to the 1/(2*TR) (i.e. the nyquist frequency).
Alternatively, you might also try to increase the censoring threshold to 0.3 and see if this helps.

Best wishes,
Cesar
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censoring

Ana Navarro Cebrian September 04, 2020 08:20AM

Re: censoring

Cesar Caballero Gaudes September 06, 2020 03:30AM

Re: censoring

Ana Navarro Cebrian September 08, 2020 11:14AM