Hi, Gwenaelle:
I only want to say thank you very very ... very much !!!.
Best
Jiansong Xu, M.D., Ph.D.
Associate Research Scientist
Dept. of Psychiatry
Yale School of Medicine
Connecticut Mental Health Center, Room S-100
34 Park St.
New Haven, CT 06519
On Feb 11, 2008, at 6:54 PM, Gwenaëlle DOUAUD wrote:
> Hi,
>
> --- Jiansong Xu <[log in to unmask]> a écrit :
>
>> Dear Friends:
>>
>> After a little bit struggle and with lot of help
>> from the list,
>> finally I can look at stats results.
> Well done (the second assumption was the good one:
> swap MNI152_T1_1mm for the FMRIB58_FA_1mm).
>
>> I have one group 16 subjects. I assessed the
>> correlations between age
>> and FA with following procedures.
>>
>> 1. Glu_gui, one EV, type in demeaned age,
>> 2. set up two contrast [1] and [-1].
>> 3. randomise
>>
>> I have following questions
>>
>> 1. -c 2, this option allow me to assess p at
>> cluster level. What
>> does 2 mean here? Is it t threshold of each voxel?
> Yes
>
>> If so, am I right
>> by saying that voxles form a cluster if all of them
>> has t > 2 and also
>> contiguous with each other.
> Yes
>
>> The p in maxc_tstat is
>> dependent on both
>> the t value and number of voxels (extent) in the
>> cluster, so this p is
>> the p value of each cluster.
> Yes
>
>> 2. vox_tstat contains the p of each voxel. the p in
>> this file is not
>> very useful for reporting result, because not
>> corrected for multiple
>> comparison
> That's right
>
>
>> 2. what the mean of p in max_tstat?
> Voxel-based corrected with the family-wise error
> (FWE). Very conservative. Please have a look at:
> http://www.fmrib.ox.ac.uk/fsl/randomise/index.html
> You might also want to give a try to the TFCE...
>
> Cheers,
> Gwenaëlle
>
>>
>> Best
>>
>> Jiansong Xu, M.D., Ph.D.
>> Associate Research Scientist
>> Dept. of Psychiatry
>> Yale School of Medicine
>>
>> Connecticut Mental Health Center, Room S-100
>> 34 Park St.
>> New Haven, CT 06519
>>
>
>
>
>
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