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An fMRI story--- for each subject we performed three runs- each run was essentially the same except for the order of conditions (blocks) was counterbalanced. I used Roger Woods tools to do my data pre- processing and now have everything in 'analyze formate' -- I'm intending to eventually do a random effects analysis but understand I must first generate a fixed effects model --- QUESTION: Should I concatinate runs so that I have one long session for each subject or should I treat each run as a single session in my fixed effects model? (for random effects) If I treat each run as a single session ...... I have 12 subjects - - I end up with 36 sessions - is there any way to create 'true' single subject contrast (incorporating the 3 runs) within the fixed effect model or do I creat a single contrast for each of the 36 sessions that will then be used in the random effects analysis? If I end up with 36 single 'session' contrast' do I need to then specify in my random effects model that session 1,2,3 all correspond to subject one or do I just work with the 36 contrast as independent measures? Thank YOU - Thank YOU - THANK YOU - to whomever can help me resolve these issues----