> Date: Fri, 23 Nov 2012 14:44:06 +0000
> From: [log in to unmask]
> Subject: [SPM] Between-group difference in structural connectivity (VBM)
> To: [log in to unmask]
>
> Dear SPM/VBM users,
>
> I have performed a VBM T-test identifying an area of grey matter volume difference between two groups. Then I made an analysis of 'structural connectivity' by taking the voxel value at the peak voxel coordinate for each subject and using it as a regressor in a linear regression model for each group. Here I found another area that was positively correlated to the first one. The finding was present in both groups but the cluster differed in size and p-value.
>
> How can i compute the difference in correlation of the two areas between the two groups? Subtraction of betas or thresholded T-maps ? A completely different model?
>
> I am grateful for any suggestions!
>
> / Carl Johan Ekman
> MD, PhD-student
> Karolinska Institutet
> Stockholm, Sweden