Dear all,

I am new to the CONN toolbox and have a question about setting a between-condition contrast at the second level analysis. I have four conditions (A, B, C, and baseline). A, B and C are the reading task. After the ROI-ROI connectivity analysis, I would like to check if there is an overall task effect in reading versus baseline (i.e., (A, B, C) > baseline). But I am not sure how to set the contrast. Shall I give a contrast, [ 1 1 1 -3] or [1 1 1 -1] or [1 0 0 0;0 1 0 0; 0 0 1 0; 0 0 0 -1] or [1 0 0 -1; 0 1 0 -1; 0 0 1 -1]? I have tried all of these options, and the results are different so I would like to make sure which one is correct (or none of them!)? I think that I have not had clear understanding about how the conditions can be combined so I would appreciate your help and suggestions!

best,
YaNing