Thanks for the slides. The help files are useful, too. However, let me
ask a specific implementation question.
Suppose I have one Task (T), one Regressor of interest (R1), 6 motion
regressors (M1 to 6)and two sessions.
Now, I want to test whether R contributes to the model.
What string to I enter in the contrast manager?
This appears to be an F-contrast (or T-contrast) and the Full model
Session 1 Session 2
T R M1 M2 M3 M4 M5 M6 T R M1 M2 M3 M4
1 0 0 0 0 0 0 0 1 0
0 0 0 0 0 0
So in the above string I am controlling for the Regressor and the
But I now want to know if, given the Task T, my custom regressor
contributes to the Model
How do I set that up in the contrast manager?
On May 19, 2009, at 1:59 PM, Guillaume Flandin wrote:
> Dear Michael,
> Yes, an F-test allows you to compare nested models and you can
> easily do
> that in SPM. See slide 20:
> and Section 5.1, page 12:
> for a bit of theory and the SPM manual p.233 for a practical example:
> Note that SPM also allows to compare non-nested models with Bayesian
> inference by comparing model evidence maps, see:
> This is available in SPM8 under:
> SPM > Stats > Bayesian Model Selection > BMS: Maps
> Best regards,
> Michael Froelich wrote:
>> does anyone have an idea how I would go about comparing the model
>> of a
>> block-design fMRI dataset with a regressor to the same without
>> regressor. In
>> simple statistics one could do this with an F-test.
>> Can SPM produce a contrast image comparing these two models?
> Guillaume Flandin, PhD
> Wellcome Trust Centre for Neuroimaging
> University College London
> 12 Queen Square
> London WC1N 3BG