Dear FSL experts,
We would like to run a 2x2 Mixed ANOVA with Factor 1: Time (Pre- vs Post- treatment; within-subjects factor) and Factor 2: Group (Medication vs Placebo; between-subjects factor). We are interested in testing whether there is a GroupxTime interaction (e.g., a differential change in the medicated group). We set up on 2x2 Mixed ANOVA model following the guide on the FSL website.
We would just like to check that we setup up our interaction model correctly. This is an excerpt from our 2x2 Mixed ANOVA design:
Group EV1 EV2 EV3 EV4 EV5 EV6 EV7 …
Run GxRun Subj1 Subj2 Subj3 Subj4 Subj5
1 -1 -1 1 0 0 0 0
1 1 1 1 0 0 0 0
1 -1 1 0 1 0 0 0
1 1 -1 0 1 0 0 0
1 -1 -1 0 0 1 0 0
1 1 1 0 0 1 0 0
1 -1 -1 0 0 0 1 0
1 1 1 0 0 0 1 0
1 -1 1 0 0 0 0 1
1 1 -1 0 0 0 0 1 …
Where EV1 Run is determined by Pre- (-1) vs Post (1) and the Interaction terms GxRun is determined by the subjects' inclusion in the Placebo (Run coding x1) or Medication ( Run coding x-1) group. Does this model setup look reasonable to test the interaction effect?
Thank you,
Caroline
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