Hi Everyone,

I am conducting my second project with the CONN toolbox. I am working with a cross-sectional group (n = 105; 1 MRI session) of older adults with MCI. For context, I am using version 20.b of CONN and data was imported after being pre-processed in fMRIPRep. 

I have reached the Denoising stage. My scrubbing parameters are (I THINK) quite high (229p). I have also reviewed the QC-FC associations via the QA plots and see that Mean GS change, Mean Motion, and valid scans % match with NH DECREASE after the current denoising stagey. My questions are as follows: 

1) How concerning is this DECREASE? As per Alfonso's handbook, > or = 95% is considered the "goal" (https://www.researchgate.net/publication...)

2) A select # of participants are quite troublesome (i.e., scrubbing over half the volumes). Is there a way to exclude/ignore a single participant at the denoising level to evaluate its impact on the overall QA plots

3) As a follow-up to #2, I recognize there is no gold-standard for denoising but was wondering if there is a "guideline" on how many volumes should be scrubbed before a participant is removed entirely. It was briefly discussed in this thread: https://www.nitrc.org/forum/forum.php?thread_id=6528&forum_id=1144

Thank you in advance.

Cheers,

Nick