Thanks, Bob.

A prepackaged solution would certainly be appreciated, but, I'm worried about the cost to validity. It sounds like the easy way out might not be worth it.

The goal is to mask out the global non-neural signal (and thus non-gray matter) and then use the mask during preprocessing to blot out the non-neural signal.

The elaborate method I had in mind was to
1. segment WM from the anatomical in something like FSL
2. import it to AFNI and 3dfractionize to EPI resolution
3. import to excel for power spectrum analysis
4. run through 3dTfitter
5. and this last step I'm unsure of more than others, but, might I so something as simple as subtract it with 3dcalc from original EPI?

Thanks again for your input.

Andrea