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Dear SPMers, I think I have now read all the threads on conjunction analysis, but I am still unsure how to set it up properly. I tried all constellations and results vary a lot. First of all, I'd like to use the "global" null option as offered by SPM, because the "conjunction" option will be to conservative for my data (including similar options that use imcalc to compute common regions/ overlaps). The correct way for one group of subjects that underwent several conditions seems to use a 2nd level one-way ANOVA (not the within-subject one) and to do the proper adjustments for sphericity. However I am not sure on sphericity. Levels of the factor are probably dependent, so is it correct to set the independence option (stats.factorial_design.des.anova.dept = ) to NO (= 1)? I am even less sure about the variance option (stats.factorial_design.des.anova.variance =), and this even seems to be more critical. What would be the appropriate setting here? My data look nice if I use equal variance, and less expected if I use unequal variance. What is the analoguous way to set this up for two groups of subjects that underwent the same, say 4, conditions. Ideally, I'd like to obtain SPMs for both groups separately and then also the group comparison for the conjunction. I think I know how to define all the contrasts needed, but again I do not know how to properly set up the model. Use of full-factorial or flexible factorial? What independence and variance options should be applied to the group and condition factors? Any help is highly appreciated. Thank you, Jens -- Jens Kronschnabel, Ph.D. student Department of Child and Adolescent Psychiatry, University of Zurich Neumünsterallee 9, CH-8032 Zürich, Switzerland +41 43 499 2650 [log in to unmask] --