Dear SPM'ers
When is it reasonable to perform a subject specific subtraction analysis
(Multi-subj: cond x subj interaction & covariates) as fixed effects
analysis? Is it reasonable for example in a study of emotion (2
conditions, 4 replications/cond, 88 scans)?
We used a contrast [1 -1 ... 1 -1] (contrast vector of 22 components,
11 subjects) to test the average difference. Is this correct?
Esa Wallius
Turku PET Centre, Finland
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