Hi Douglas,

Thanks for your reply. I am not sure how to do this with design matrix. I am trying to get higher order fit. Basically I want to see that whether the cortical thickness varies in a quadratic fashion with the behaviour score.

Are you are suggesting that I should put square root values of the behavioural scores in the design matrix? I am not sure if that is the right approach.

Looking forward to hearing back from you.

Abhinav

On Wed, 20 Feb 2019, 04:12 Greve, Douglas N.,Ph.D., <DGREVE@mgh.harvard.edu> wrote:

It sounds like you will just need to create your own design matrix and
then feed it into mri_glmfit with --X (and not include --fsgd)

On 2/12/19 12:03 AM, Abhinav Yadav wrote:
>
> External Email - Use Caution
>
> Hello,
>
> I am trying to do GLM analysis for cortical thickness with a
> behavioral score. I wanted to explore square fit in the GLM. Basically
> wanted to see weather the behaviour is related in a quadratic function
> instead of linear one.
>
> Couldn't find any option for this is GLM fit.
>
> I was thinking of feeding a squareroot values of the behavioural
> parameter in the GLM as an alternative. But not sure weather that will
> work. Please any one can help me with this.
>
> Thanks,
> Abhinav
>
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