Hi,
Google "interaction continuous variables" and post-back if it isn't clear.
Make sure you demean MMSE, age, and HR response.

cheers,
-MH

-- 
Michael Harms, Ph.D.
-----------------------------------------------------------
Conte Center for the Neuroscience of Mental Disorders
Washington University School of Medicine
Department of Psychiatry, Box 8134
660 South Euclid Ave. Tel: 314-747-6173
St. Louis, MO  63110 Email: [log in to unmask]

From: Paul Beach <[log in to unmask]>
Reply-To: FSL - FMRIB's Software Library <[log in to unmask]>
Date: Tuesday, September 16, 2014 10:35 AM
To: FSL - FMRIB's Software Library <[log in to unmask]>
Subject: Re: [FSL] within-subjects GLM

Michael,

Thanks for your response. This is what I was suspecting, but I didn't want to separate my AD corhort into a specific set of groups. How could I create an interaction term without doing that?

On Tue, Sep 16, 2014 at 11:31 AM, Harms, Michael <[log in to unmask]> wrote:

No, you would need a model with an interaction term to get at that question.

cheers,
-MH

-- 
Michael Harms, Ph.D.
-----------------------------------------------------------
Conte Center for the Neuroscience of Mental Disorders
Washington University School of Medicine
Department of Psychiatry, Box 8134
660 South Euclid Ave. Tel: 314-747-6173
St. Louis, MO  63110 Email: [log in to unmask]

From: Paul Beach <[log in to unmask]>
Reply-To: FSL - FMRIB's Software Library <[log in to unmask]>
Date: Tuesday, September 16, 2014 9:32 AM
To: FSL - FMRIB's Software Library <[log in to unmask]>
Subject: [FSL] within-subjects GLM

FSL folks,

I'm interested in performing a within-subjects analysis in an AD cohort looking at the relationship between cognitive status and a behavioral score on resting connectivity while adjusting for age and gender.

The general question I'm asking is: as Alzheimer's disease worsens (i.e. MMSE scores decrease) what are the resting neural correlates of changes in autonomic response to a pain stimulus?

I have a GLM setup and wanted to confirm the appropriate contrasts.

EVs are as follows: 
1 - MMSE
2 - Age
3 - Gender
4 - Heart rate response

My current contrast setup:
C1   PosMMSE_effect              1.0 0 00
C2   NegMMSE_effect            -1.0 0 00
C3   PosMMSE_effect_hr        1.0 0 01.0
C4   NegMMSE_effect_hr      -1.0 001.0

Will the latter two contrasts get at the question I'm asking?


Thanks
--
Paul Beach
DO/PhD candidate - Year VI
Michigan State University
- College of Osteopathic Medicine
- Neuroscience Program
 - MSU Cognitive and Geriatric Neurology Team (CoGeNT)

 

The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail.




--
Paul Beach
DO/PhD candidate - Year VI
Michigan State University
- College of Osteopathic Medicine
- Neuroscience Program
 - MSU Cognitive and Geriatric Neurology Team (CoGeNT)

 

The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail.