To the SPM experts,
I am organising the analysis for my data-set and I'd like to start with a 2 sample t-test.
I have basically 2 groups of cat scanned images. 1 group of lesioned cats (6 cats) and 1 group of controls (5 cats).
The setting for the definition of contrasts was:
-name of contrast: "Lesioned-Control";
-type t-contrast;
contrast: 1 -1.
The SPM contrast manager gives me the OK in green (ie: "1 -1 <-- (OK)") but pressing the OK button, I get an error in command windows of MATLAB telling me that "Vectors must be the same length".
Is this error come out since I have two groups with different number of subjects (lesioned group=6 and control group=5)?
Many thanks in advance for your help,
Marco
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