Dear Donald McLaren,
> You want [1 0 0] which is the positive effect, assuming a T-test, of
> your IV on volume.
>
> [1 1 1] is the average effect of your IV, age, and gender. This would
> be very hard to interpret.
Ok.
In case, I would try a two-sample t-test to compare the gray matter
volume between two groups, again controlling for the effect of age and
gender,
would the contrast be defined analogously, i.e. e.g. "1 -1 0 0"? Or
would I do this also in a multiple regression model with an additional
regressor 'group'? And would the
contrast be "1 1 0 0" then (for "group", "IV", "age", "gender")?
Thank you very much for your help!
All the best,
-Lucas
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