Dear SPM experts,
We are using a Flexible Factorial design that includes 2 groups and 2 conditions for each subject (repeated measures). In the design matrix we included the main effect for group, the main effect for condition, and the interaction group x condition (in total, 8 columns). When defining the contrasts, we are only interested in the interaction group x condition (last 4 columns of our design matrix).
After creating the contrasts, we now want to extract the beta values and standard errors for a specific voxel. We know that it is possible to do this by plotting contrast estimates, choosing the contrast and checking the values in the Matlab workspace. The problem is that we do not seem to be able to do it just for a single interaction group x condition (e.g., G1C1).
Is there a way to get the variability (standard error) only for a single interaction, without also weighting the group/condition in the main effect?
Thank you in advance for your help.
Best regards,
Cecilia
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