Re: [Freesurfer] [FreeSurfer] Repeated Measures ANOVA in FSFAST

Hi Doug,

Upon reviewing the repeated measures ANOVA tutorial on the Freesurfer website I was able to revise the fsgd file (below) to what I now think is more accurate.

I'm treating each observation of a condition (risk-reward pairing) and indicating that each of those observations belong to the same subject (Subject1, Subject2, etc).

GroupDescriptorFile 1 Class Subject1 Class Subject2 Variables hRisk-vs-lRisk hRisk-vs-mRisk Input Subject1-lRsk_lRwd Subject1 -1 0 Input Subject1-lRsk_mRwd Subject1 -1 0 Input Subject1-lRsk_hRwd Subject1 -1 0 Input Subject1-mRsk_lRwd Subject1 0 -1 Input Subject1-mRsk_mRwd Subject1 0 -1 Input Subject1-mRsk_hRwd Subject1 0 -1 Input Subject1-hRsk_lRwd Subject1 1 1 Input Subject1-hRsk_mRwd Subject1 1 1 Input Subject1-hRsk_hRwd Subject1 1 1

Input Subject2-lRsk_lRwd Subject1 -1 0 Input Subject2-lRsk_mRwd Subject1 -1 0 Input Subject2-lRsk_hRwd Subject1 -1 0 Input Subject2-mRsk_lRwd Subject1 0 -1 Input Subject2-mRsk_mRwd Subject1 0 -1 Input Subject2-mRsk_hRwd Subject1 0 -1 Input Subject2-hRsk_lRwd Subject1 1 1 Input Subject2-hRsk_mRwd Subject1 1 1 Input Subject2-hRsk_hRwd Subject1 1 1

Please let me know if you think this design looks more correct given the observations per subject.

Thanks 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

________________________________________ From: freesurfer-bounces@nmr.mgh.harvard.edu [freesurfer-bounces@nmr.mgh.harvard.edu] on behalf of Afzal, Afsana [AAFZAL@mgh.harvard.edu] Sent: Monday, February 22, 2016 2:34 PM To: Freesurfer support list Subject: Re: [Freesurfer] [FreeSurfer] Repeated Measures ANOVA in FSFAST

Hi,

Sorry about the lack of clarification.

Yes, it's a functional study. Each of the classes is a subject. I basically want to compute the main effect of risk at the group level (i.e. High Risk minus Low Risk) but there are multiple observations per risk level since there are three different reward levels within each risk level (low Reward, med Reward, high Reward). I was thinking of setting up all the risk-reward conditions as active (=1s) in the fsgd file and then subtracting the conditions using the contrast matrices below to get the main effect of Risk.

Please let me know if that makes a bit more sense.

Thanks 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

________________________________________ From: freesurfer-bounces@nmr.mgh.harvard.edu [freesurfer-bounces@nmr.mgh.harvard.edu] on behalf of Douglas N Greve [greve@nmr.mgh.harvard.edu] Sent: Monday, February 22, 2016 12:16 PM To: freesurfer@nmr.mgh.harvard.edu Subject: Re: [Freesurfer] [FreeSurfer] Repeated Measures ANOVA in FSFAST

I'm having a hard time deciphering what you are doing. Is this a functional study? What are the 5 classes? Why are there all 1s regardless of risk or reward level?

On 02/19/2016 10:52 AM, Afzal, Afsana wrote:

Hi,

I'm analyzing a decision making task with a 3x3 condition matrix: pairings of low, medium, high levels of risk with low, medium, high levels of reward.

I've set up the following FSGD file to do a repeated measures/within-subject ANOVA:

GroupDescriptorFile 1 Class hc001 Class hc002 Class hc003 Class hc004 Class hc005 Variables lRsk_lRwd lRsk_mRwd lRsk_hRwd mRsk_lRwd mRsk_mRwd mRsk_hRwd hRsk_lRwd hRsk_mRwd hRsk_hRwd Input hc001 hc001 1 1 1 1 1 1 1 1 1 Input hc002 hc002 1 1 1 1 1 1 1 1 1 Input hc003 hc003 1 1 1 1 1 1 1 1 1 Input hc004 hc004 1 1 1 1 1 1 1 1 1 Input hc005 hc005 1 1 1 1 1 1 1 1 1

I've also created the following contrast matrices:

Con1: Does difference between highRisk andLowRisk differ from 0? 0 0 0 0 0 -1 -1 -1 0 0 0 1 1 1

Con2: Does difference between highRisk andMedRisk differ from 0? 0 0 0 0 0 0 0 0 -1 -1 -1 1 1 1

Is this an appropriate way of setting up the ANOVA?

Thanks 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

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