Submitted by vvillalta on Wed, 09/19/2012 - 18:50
Dear all,
We have analyzed alff and falff comparing HC and OCD subjects within different bands (slow 2, 3 4 and 5). We would like to regress cardiac and respiratory information from the alff/falff maps. Could you please indicate me how to do so?
Thanks very much for your help!
Victoria
Submitted by Qing Zhao on Wed, 09/19/2012 - 21:31 Permalink
wish these can help you
if you recorded cardiac and respiratory information, I think it is only possible to regress them from the BOLD signal before calculating ALFF/fALFF. you can calculate ALFF/fALFF from regressed data.
REST can help you to do linear regress. However, if you want to use RETROICOR, I think you need to write scripts by yourselves follow Glover's algorithm.
By the way, there has been some papers concerned cardiac and respiratory noise, it seems just RETROICOR may not work well enough.
You can see:
"Separating respiratory-variation-related fluctuations from neuronal-activity-related fluctuations in fMRI" Birn et .al. Neuroimage 2006
"Influence of heart rate on the BOLD signal: The cardiac response function" Chang et.al. Neuroimage 2009.
wish these can help you