Hi Ged!!

Thanks a lot for your explanation!!

Im using the softaware CONN. When you reach the point of second level results, you need to select the groups you are trying to compare and then you type the contrast. For instance, if I only have 2 groups, I'll select those  2 groups and type 1 -1 or -1  1 for the contrast. My question is what to type in order to test for group effect differences (ANOVA), since I´ll be selecting the 3 groups.  

You think What you kindly explained to me may also be applied for the CONN?

Thanks a lot!!

Marisol P.