Hi, sorry I must have missed your response last week. Yes, I'm doing an identical analysis: comparing 2 groups of kids (controls and ADHD) in cortical thickness, controlling for age and demeaned ICV (nuisance). So all the parameters are the same. I'm attaching 3 screen shots: group differences using 5.0 before using Monte Carlo correction (lots of clusters), group differences before correction using 5.3 (few small clusters), and group differences using 5.0 after correction (frontal cluster). there was nothing sig. remaining after correcting for multi. comparisons using 5.3. I'm puzzled about why the differences are so large. I selected DODS in 5.0, so everything should be the same? 

Thanks!

Maria

******

Message: 10
Date: Tue, 18 Jun 2013 23:34:10 -0700
From: Douglas Greve <greve@nmr.mgh.harvard.edu>
Subject: Re: [Freesurfer] qdec differences in FS 5.0 vs 5.3
To: freesurfer@nmr.mgh.harvard.edu
Message-ID: <51C150E2.1080604@nmr.mgh.harvard.edu>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed


Hi Maria, can you elaborate on exactly what you have done? Is the data
the same and you are only changing the version of QDEC? What is the
nature of the difference? Can you send pics or stats?
doug


On 6/18/13 6:06 AM, Maria Kharitonova wrote:
> Hi,
>
> I'm learning how to use QDEC and was comparing results that it produces under FresSurfer 5.0 vs 5.3. I know the 5.0 has an option for either DODS or DOSS method of producing a design matrix, while the 5.3 only has DODS. This suggests that results should be identical (or at least similar) across versions if I select DODS. However, I'm getting very different results based on the version I select: complete lack of differences across groups in 5.3 and a predicted pattern of differences in 5.0 using DODS. I'd like to understand where the differences are stemming from -- any ideas?
>
> Thanks in advance!
> Maria
>
> *******************************
>
> Maria Kharitonova, Ph.D.
> Postdoctoral Research Fellow
> Laboratories of Cognitive Neuroscience
> Boston Children's Hospital
>
>
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