re Henrike
> to compare patients and control we used a paired t-test.
you have to use a two-sample t-test - paired is for the same subjects
tested twice (in time or conditions)
> Each pair consisted of a patient and his/her matched control. In the
> contrast "patients > controls" we found activation differences in the
> amygdala. To find out why these differences exist (Both groups show
> activation, but the patients show more activation? The patients show
> activation, but the controls deactivation? Both show deactivation, but
> the controls more deactivation?) I would normally define an additional
> F-contrast "Effect of interest" ([1 0; 0 1]) and look at the parameter
> estimates. SPM does not allow me to do that? Why is it not possible in
> paired t-tests?
>
well I guess I don't need to answer this since this is the wrong model ...
C
--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.
|