Dear all, Suppose I'm doing a 2x2 test: [A,B] x [+,-] and I want to test for difference in activations between A+ and B+ in group level to see which is stronger. Which statistical test should I choose at the first level and at the second level? I suppose full factorial is most flexible. Suppose I got some activations after running both levels with full factorial, can I just pick some of the contrasts and run second level again with a different model? Thanks a lot in advance. Best, Andy