For any difference between controls and patients, use the F-contrast [1
-0.5 -0.5]. For controls > patients, use the t-contrast [1 -0.5 -0.5],
and for patients > controls, use the t-contrast [-1 0.5 0.5].
On 06/04/17 15:57, Hector Espinos wrote:
> Dear SPM Users,
> We have done the second level analysis between a control group and a two
> group of cirrhotic patients, one with encephalophaty and other without.
> We would like to know if there is more activation in the control group
> or in the patient groups.
> We understand that to be able to tell if a zone has been activated or
> deactivated we would have to compare the size of the betas in the second
> On the other hand, as experts would ask you how we can do that and what
> would be the best strategy to do it?
> What is the sense of the change of the sign in the betas?
> Thanks in advance!
Guillaume Flandin, PhD
Wellcome Trust Centre for Neuroimaging
University College London
12 Queen Square
London WC1N 3BG