Dear Marko and Guillaume,
Thank you for your emails. We used the same preprocessed dataset as an
input for the statistics step (flexible factorial) in all cases
(MATLAB R2013a, MATLAB R2015a and MATLAB R2016b). I have attached the
screenshots of the results in the following email (I have some
problems with the message size)..
The significant voxels are located in a small volume within the brain
because the image dataset doesn´t belong to human beings.
Looking at the results, you can see for example:
1) Matlab R2013a: p(set-level) = 0.782 and the voxels of the
cluster-level are 1052 in total.
2) Matlab R2015a: p(set-level) = 0.789 and the voxels of the
cluster-level are 1137 in total. So the difference compared to Matlab
R2013a is 0.9% in p(set-level) and 8.1% in number of voxels.
3) Matlab R2016b: p(set-level) = 0.903 and the voxels of the
cluster-level are 888 in total. So the difference compared to Matlab
R2013a is 15.5% in p(set-level) and 15.6% in number of voxels.
Guillaume, tell me if it is really necessary to send you the copy of
the folders containing the SPM.mat because I am not be sure if I am
allowed to do that.
Just in case it is important, Matlab was installed using its default
settings. I didn´t remove any Matlab toolbox from the default Matlab
installation list.
Best regards!
Verónica
On 5 October 2016 at 11:24, Guillaume Flandin <[log in to unmask]> wrote:
> Hi Veronica,
>
> as Marko mentioned, it would be great if you could show us the
> differences you observe in the results you obtain when the only change
> is the MATLAB version (screenshot of the Result page and, possibly, copy
> of the folders containing the SPM.mat). I would not expect significant
> differences so it would be interesting to get to the bottom of this.
>
> Best regards,
> Guillaume.
>
> On 05/10/16 07:11, Marko Wilke wrote:
>> Veronica,
>>
>> while I do not have an answer, I believe it would be most helpful if you
>> could quantify the differences (are they on the order of .01%, 1%, or
>> 10%?), and report on how exactly you have made sure that the error is
>> only in the statistics steps (are these datasets identical, or
>> preprocessed identically in the different versions, or...). This may
>> also help to narrow it down to a real glitch or rounding differences or
>> whatever else.
>>
>> Cheers
>> Marko
>>
>> Verónica García wrote:
>>> Dear SPM experts,
>>>
>>> Which is the most appropriate version of MATLAB when using SPM12
>>> v6685? I am asking that question because we are comparing a set of PET
>>> images using a Flexible Factorial design (basic models) and the
>>> results are not the same if we use MATLAB R2013a, MATLAB R2015a or
>>> MATLAB R2016b.
>>>
>>> Thank you for any help you can provide.
>>>
>>> Best regards
>>>
>>> Verónica García Vázquez
>>>
>>
>
> --
> Guillaume Flandin, PhD
> Wellcome Trust Centre for Neuroimaging
> University College London
> 12 Queen Square
> London WC1N 3BG
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