Dear experts.
I am using the SwE toolbox to analyze data of 2 groups (30 Subjects each) of volunteers acquired in 3 time points.
I read the manual and the example analysis and tried to set the parameters:
Scans: 180 files (Group1Time1(30), G1T2(30), G1T3(30), G2T1(30), G2T2(30), G2T3 (30))
Groups: kron(1:2,ones(1,90))
visits: kron(ones(1,60),1:3)
Small sample adjustments: type 3
Degrees of freedom type: approx III
Subject: kron(1:60,ones(1,3))
Design Matrix:
"To check general differences between groups throughout the time points"
Covariate 1
vector: ones(1,90)
name: G1
Covariate 2
vector: [zeros(1,90); ones(1,90)]
name: G2
Is this correct?? The contrast vector would be simplest in this case [1 -1]...right?
"To check differences between groups time points"
Covariate 1
vector: ones(1,30)
name: G1T1
Covariate 2
vector: [zeros(1,30); ones(1,30)]
name: G1T2
Covariate 3
vector: [zeros(1,60); ones(1,30)]
name: G1T3
Covariate 4
vector: [zeros(1,90); ones(1,30)]
name: G2T1
Covariate 5
vector: [zeros(1,120); ones(1,30)]
name: G2T2
Covariate 6
vector: [zeros(1,150); ones(1,90)]
name: G2T3
Is this correct??
I found a reply email form Prof. John Ashburner on SPM Archives and he mentioned a contrast image encoding rate of change between time points. Is this a GLM (like one sample ttest, including the 3 images and a covariate vector like [1 2 3] or [3 2 1], checking the correlation ([0 1]) to creates a con_?
Thank you very much for any help!
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