Hello,
I have tried to search the archives, but there are problems loading the
page. I apologize if this is redundant.
Anyhow, I am trying to use Voxel Based Morphometry in SPM5 with a patient
group and a control group. I have found differences in grey matter on a two
sample t test - which is great, but I have a number of factors that I want
to look at in the patient sample. i.e. hippocampus volume, treatment age,
severity, dose, time to normalise, etc. I am not sure how to enter these
into the design matrix.
I have entered them all separately as covariates. Is there a way to test
correlations between the covariates - such as treatment age and severity? or
hippocampal volume and dose??
Is it simply how you enter the contrasts? I know that 1 would denote a
positive correlation and -1 a negative correlation.
Any help would be greatly appreciated!!!
Many thanks,
Jovanka
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