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Dear all, I have a fairly simple question but have got a bit confused with the different options people have suggested on the mailing list. I want to do a conjunction analysis and find regions which are common in three experiments. In my results, I want a heat map that represents the level of overlap between the three experiments. However, reading through some of the approaches that people have suggested on the mailing list, I have come up with more than one ways to do this. I would like to know which approach is better and would give me correct results: 1. Inclusive masking: I select Results from one experiment, then use inclusive masking using a thresholded t-map and see the regions common in the two experiments. Then use this t-map to mask my result from third experiment. (In this case however, I have found that the regions depend slightly on which experiments' results you use first and the heat map is not an indication of extent of overlap) 2. Use Imcalc to mask two t-maps and get the results. (In this case as well, heat map is not an indication of extent of overlap). 3. Using single contrasts: I take only the single condition contrasts (use a contrast vector 1 0 0 etc.) for all participants, take it to group level for all conditions and experiments, then run a random effects analysis on them (an approach I am not familiar with). I would highly appreciate any help in this regard. Atesh Koul Graduate student, National Brain Research Centre, India