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Dear SPMers: I need some anova help, We have a between groups one-way anova with one con image per subject taken from a two-condition fMRI paradigm. The hypothesis we wish to test is that that there will be a linear trend in group mean signal change in a specific region: g1<g2<g3<g4. Questions: 1. In basic models should i be using the straight ANOVA option, or ANOVA (with constant) to test this trend effect? 2. the contrast -3 -1 1 3 should tell me if there is a linear trend, but using equally spaced positive integers (1 3 5 7) in the contrast yields a better result when using the ANOVA no constant model, but is this contrast valid? Thanks Sterling