help > repost - retroicor files & missing values -
Dec 7, 2017  05:12 AM | Alfonso Nieto-Castanon - Boston University
repost - retroicor files & missing values -
Dear Catherine,

Yes, simply entering either a completely empty .txt file or one containing all zeros for the cases (subjects/sessions) where you have no data should work perfectly fine. Please let me know if you run into any issues. 

Then there is the question of whether these few subjects having undergone slightly different preprocessing than the rest (no Retroicor correction) may impact/bias your results. For this I would probably suggest to make post-hoc second-level analyses, where  you include an additional second-level covariate encoding these few subjects as a group, and you simply check your main results after correcting for potential group differences between the "full-retroicor-data" vs. "no-retroicor-data" groups, just to be safe.

Hope this helps

Originally posted by Catherine Hubbard:
I'm reposting this thread hoping to get some advice, apologies for the redundancy. Thanks!

Dear Conn Users,
I'm performing a seed-based connectivity analysis using conn, I have retroicor .1D files that i want to use to correct for physio noise (to be added as regressors) in addition to acompcor. I've uploaded these retroicor files in 'setup' under the covariate 1st level tab, the problem is that I'm missing some files from a few subjects due to the physio (hr and resp) being too noisy to annotat. When I go to run this conn complains saying I cannot have missing values. Any ideas how I can resolve this? Would it be fair in these instances to upload .txt files that contain a non-zero number representing each acquired volume? Any recommendations?

Thanks in advance for the help!
Kindest regards,

Threaded View

Catherine Hubbard Dec 6, 2017
repost - retroicor files & missing values -
Alfonso Nieto-Castanon Dec 7, 2017
Catherine Hubbard Dec 8, 2017