interpolated source activity values = NaN

[Ingrid Nieuwenhuis]

Dear Frederic,

 

Could it be that you wrote down the indices of the voxels before
interpolating? Since the voxels before interpolating do not match anymore
after interpolating onto the template_mri.

 

Best,

Ingrid

 

 

  _____  

From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
Of Frederic Roux
Sent: Friday, December 04, 2009 2:51 PM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: Re: [FIELDTRIP] interpolated source activity values = NaN

 

Hi Ingrid,

thanks for the quick reply. I will try your suggestion but I am pretty much
sure that the values I want to look at are inside the brain.

My approach is the following:

I want to indentify the voxels that show significant activation.
So first I visualized my data with sourceplot and cfg.interactive = 'yes'
and then I write down the indices of the voxels onto which I click.

When I feed these indices into SourceInterpolatedStats.stat([x y z]) this
returns me NaNs, even tough the voxel was clearly located inside the brain.

Do you have any idea of why this happens?

Frederic

  _____  

Date: Fri, 4 Dec 2009 13:21:17 +0100
From: ingrid.nieuwenhuis at FCDONDERS.RU.NL
Subject: Re: [FIELDTRIP] interpolated source activity values = NaN
To: FIELDTRIP at NIC.SURFNET.NL

Hi Frederic,

 

Probably the NaN’s are the voxels outside the brain. The source estimate is
only performed for voxels inside the brain, the voxels outside are put to
NaN. In the field “inside” it is coded which voxels lay inside the brain.
Try:

SourceInterpolatedStats.stat(SourceInterpolatedStats.inside)

This should give you the non-NaN values.

 

Hope this helps,

Ingrid

 

 

  _____  

From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
Of Frederic Roux
Sent: Friday, December 04, 2009 12:51 PM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: [FIELDTRIP] interpolated source activity values = NaN

 

Hi everyone,

I would like to use the values that correspond to the interpolated
statistics at source level. 
The problem is that most of these values are NaNs, even tough I can
visualize them with sourceplot.

Here are the steps I am doing to compute these values:

[signal1] = sourcegrandaverage(cfg,data);
[signal2] = sourcegrandaverage(cfg,data);

[Stats] = sourcestatistics(cfg,signal1,signal2);%the statistics used here is
depsamplesT using fdr and clusterstatistics = maxsum
[SourceInterpolatedSats] = sourceinterpolate(cfg,Stats,template_mri);

This yields:

SourceInterpolatedSats =

       inside: [91x109x91 logical]
         stat: [91x109x91 double]
          dim: [91 109 91]
    transform: [4x4 double]
      anatomy: [91x109x91 double]
          cfg: [1x1 struct]

But when I try :

SourceInterpolatedStats.stat([20 45 68]) = NaN.
And this holds true for almost any index.

Does anyone know if it's possible to access these values?

Frederic

  _____  

Alle E-Mail-Adressen online auf einen Blick Ich will Hotmail!
<http://redirect.gimas.net/?n=M0912IWHM> 

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The aim of this list is to facilitate the discussion between users of the
FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and
EEG analysis.
http://listserv.surfnet.nl/archives/fieldtrip.html
http://www.ru.nl/fcdonders/fieldtrip/
----------------------------------
The aim of this list is to facilitate the discussion between users of the
FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and
EEG analysis.
http://listserv.surfnet.nl/archives/fieldtrip.html
http://www.ru.nl/fcdonders/fieldtrip/

  _____  

Nie mehr um Weihnachtsgrüße verlegen: mit tollen
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----------------------------------

The aim of this list is to facilitate the discussion between users of the
FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and
EEG analysis.

http://listserv.surfnet.nl/archives/fieldtrip.html

http://www.ru.nl/fcdonders/fieldtrip/


----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/neuroimaging/fieldtrip.
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