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<p>Dear all,<br>
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<p>I have a EEG dataset, collected with a Biosemi system with 64 channels. I don't have the individual anatomical data for each participant, but I want to perform source reconstruction to have at least a rough localization of the activation I find.<br>
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<p>Therefore, I intend to use the templates provided by fieldtrip. If I understand correctly, independently of the source modelling technique that I will choose to use, I need the following information:<br>
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<p style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px;">1) the <strong>head model</strong> : this would be the template '<em>standard_bem'</em><br>
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<p style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px;">2) the <strong>source model</strong> : the template '<em>cortex_5124.surf.gii</em>'<br>
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<p style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px;">3) the <strong>elec information</strong> : this file should describe the spatial configuration of the electrodes, but I can't retrieve it. I don't think any of the templates available
fits my data (they all have more than 64 channels and different configurations). </p>
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<p style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px;">I tried to use the function ft_read_sens on my data but I get the following error<br>
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<p><span style="font-size: 12pt;">elec = ft_read_sens([</span><span style="font-size: 12pt;">data_filt5.mat'],'senstype','eeg');</span></p>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);">Undefined function or variable 'lab'.</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);">Error in channelposition (line 316)</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);">n = size(lab,2);</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);">Error in ft_datatype_sens (line 349)</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);"> [chanpos, chanori, lab] = channelposition(sens);</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);">Error in ft_datatype_sens (line 158)</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);"> sens = ft_datatype_sens(sens, 'version', '2011v2');</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);">Error in ft_read_sens (line 380)</span></div>
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<div><span style="color: rgb(255, 0, 0); text-decoration: none solid rgb(255, 0, 0);">sens = ft_datatype_sens(sens);</span><br>
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<p>I found the cartesian coordinates of the electrodes on the Biosemi website, with the x y z coordinates for each electrodes (as the little example I'm giving below, but that's not enough. <br>
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<span style="font-size: 12pt;">Channel x</span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;">y</span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;"> </span><span style="font-size: 12pt;">
z</span><br>
<span style="font-size: 12pt;">Fp1 -27.0333934563814</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">83.2002299946862</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">-3.05493522574547</span><br>
<span style="font-size: 12pt;">AF7 -51.4205700085246</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">70.7743429000555</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">-3.05493522574547</span><br>
<span style="font-size: 12pt;">AF3 -35.5608995849164</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">76.2605952593987</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">24.1279774030766</span><br>
<span style="font-size: 12pt;">F1 -25.1195714566887</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">62.1731210759014</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">56.2665567427342</span><br>
<span style="font-size: 12pt;">F5 -47.7073482911603</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">58.9136687505812</span><span style="font-size: 12pt; white-space: pre;">
</span><span style="font-size: 12pt;">43.7676114900325</span><br>
<p>... ... ... ...</p>
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<p><strong>Do you have any suggestions on how to create a correct elec file fitting my data?</strong><br>
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<p>Any help would be highly appreciated!<br>
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<p>Silvia<br>
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