Hello,

During the denoising step, the CONN toolbox shows a histogram of the voxel-to-voxel correlation. It seems that we would prefer a normal distribution centered around zero after denoising. Is it because when we are doing resting-state functional connectivity, we do not expect that the overall connectivity across the brain to be either positive or negative, and thus should be normally distributed around zero?

If so, during a task-based functional connectivity, if we have a reason to expect more positive connectivity than negative connectivity to happen, would we expect that the histogram be negatively skewed?

I am primarily interested in how we should use the histogram under task-free as well as task-based fMRI. Any help is greatly appreciated!

Many thanks,
Daniel Yang