Hello,

After a week of desperate troubleshooting, any advice on the following matter would be welcome. 
I preprocess my data in SPM and use conn for denoising and extracting timeseries for my ROIs (Glasser parcellation, 1 parcellation per session). All data is in subject space.  I have 20 young subjects and 8 resting-state sessions for each of them.

When plotting the timecourses of the ROIs from the left hemisphere (in red) vs the timecourses of the ROIs from the right hemisphere (green), there is always more variability (noise?) in the right hemisphere [file attached]. This is consistent across all subjects and all sessions... Does any of you have an idea where this bias comes from? And how could I correct it or what should I check for additionally?

Any hint would be greatly appreciated. Thank you in advance!

Cheers,
Julia