Yes, that all looks right to me.

On 3/14/2023 6:00 PM, mariangela asimina wrote:

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Dear experts,

I am looking into the covariance of the volume of subcortical structures with cortical vertex-wise volume, comparing between two groups, correcting for the effects of gender, age and eTIV. My approach was to extract the volume of a subcortical region from the aseg.stats file and add it as a covariate into the FSGD and Contrasts files.

My FSGD therefore is in the form Class HCm Class HCf Class SZm Class SZf variables age eTIV L-ThaVol

I have normalized all continuous variables, and have 12 different FSGD files, one for each subcortical area of interest

My Contrasts matrix, to test for differences in volume covariance between HC and SZ in either slope or intercept, is the following (16 regressors): 0.50.5   -0.5   -0.5   0   0   0   0   0   0   0   0   0   0   0   0 0   0   0   0   0   0   0   0   0   0   0   0   0.5   0.5   -0.5   -0.5

Is this the right approach, and if yes is the contrast matrix correct? Or is there a way to do test for structural covariance through FreeSurfer commands?

I would appreciate any help!

Mariangela

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