Hello,

I am working on a project with fibromyalgia patients.  We have a BOLD resting state on 15 patients pre and post hyperbaric treatment.
And we have pain scores (pre and post) ranging from 0 to 100.

- I did all the default pre-processing.
- Then, I input the pre-post difference of the pain scores.
- I used the ROI-to-ROI analysis

In Subject effects, I selected "all patients" and then "pain scores difference".
For Between-subjects contrast I wrote [1 0]  (or simple main effect of "all subjects")

For condition:
pre
post

Between con contrast: [-1 1]


The question is:

Should I input a "percentage difference" for the pain scores or simply a difference?
Because I get difference answers whether I input one or the other.


Thank you .

Julien.