[Freesurfer] Group level analysis: Specifying contrasts

Hi,

I want to perform a linear regression for a task with 3 different risk conditions (low, medium, high) with the following linear trend: low = 1, medium = 2, high = 3.

Right now I'm specifying the above weighted under each risk condition in my contrast matrix. Is this the correct approach? I want to make sure I am calculating a regression and not a weighted average.

Thank you for your help,

Afsana

______________________________ Afsana Afzal Clinical Research Coordinator Massachusetts General Hospital Division of Neurotherapeutics Department of Psychiatry: Neurosciences 149 13th St, Room 2612 Charlestown, MA 02129 Phone: 617-643-5129 Fax: 617-726-4078