Correlations

Hi!

Given two groups coded as "patients" and "controls" and "patients_rating" and "controls_ratings" (symptoms scores), what is the difference between:

Selected only "patients_rating" in between subject contrast: 1 (effect of patients rating)
or "patients_rating" and "patients": 1 0 (simple main effect of patients_rating")?

Both -1 1 in between-condition contrast (post>pre).
The question is what is the correlation between the post-pre difference in connectivity of a seed (seed-to-voxel) and symptoms for patients.

I would appreciate your comments on that.
Best,
Lucas