Hello,

My question has to do with 3dRSFC.

I have resting date fmri data from a single subject.

I then used the following command:
3dRSFC -prefix PREFIX 0.01 0.1 INPUT_NAME

What this does is that it acts as a bandpass filter in order to filter out too high or low signal intensities. It then outputs the alff, falff malff, rsFA. and some other parameters.

The output of this however were values that were assigned to each voxel. I was expecting to get a single value (average for all the voxels), but instead the program assigns a single value to each voxel. My question now is, how would I get statistics in order to make a comparison between different outputs? A paper I read said the following which still has me confused: "In our previous work, the ALFF of each voxel was divided by the individual global mean of ALFF within a brain-mask, which was obtained by removing the tissues outside the brain using software MRIcro "

where does one get a global mean? Is that just a brain with the skull extracted? which can be obtained by BET from FSL?
Even then... how do I do this? given I have a bunch of output files that are images of the brain and not a single value.

Lastly, the next step in this paper was:
"The individual data was transformed to Z score (i.e., minus the global mean value and then divided by the standard deviation) other than simply being divided by the global mean."
Again, how would I do this? It sounds really straight-forward, but it's so confusing to me.

ps. I'm trying to follow the flowchart presented by FATCAT here: [afni.nimh.nih.gov].
But I'm still confused as to how they obtained the statistics? how would I obtain values which I can compare in a paper? And would I have to perform a t-test on it?

Any assistance would be greatly appreciated! I've been struggling with this for quite some time.

Thanks in advance.