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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">Dear Heather,<br>
<br>
An electrical distance-based analysis may also be helpful in looking for salt bridges or certain other oddities in the data. I would recommend the eBridge script for EEGLAB presented in Alschuler et al., 2014 and based on the intrinsic Hjorth approach presented
in Tenke and Kayser, 2001 (see<a href="http://psychophysiology.cpmc.columbia.edu/eBridge" target="_blank"> http://psychophysiology.cpmc.columbia.edu/eBridge</a> for the script and full citations).<br>
<br>
Best,<br>
Dan Alschuler
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<div style="direction: ltr;" id="divRpF877518"><font face="Tahoma" size="2" color="#000000"><b>From:</b> eeglablist-bounces@sccn.ucsd.edu [eeglablist-bounces@sccn.ucsd.edu] on behalf of K Jeffrey Eriksen [eriksenj@ohsu.edu]<br>
<b>Sent:</b> Tuesday, November 11, 2014 3:53 PM<br>
<b>To:</b> 'Benz, Heather *'; eeglablist@sccn.ucsd.edu<br>
<b>Subject:</b> Re: [Eeglablist] Old EGI system<br>
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<p class="MsoNormal"><span style="color:#1F497D">Heather,</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D">In general I think visual inspection should be sufficient. I have two other suggestions:</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoListParagraph" style="text-indent:-.25in"><span style="color:#1F497D"><span style="">1.<span style="font:7.0pt "Times New Roman"">
</span></span></span><span style="color:#1F497D">Borrow a new (or trusted) Net from someone in another lab and run a short EEG on a single subject with each Net for comparison. Besides visual comparison you could look at impedances.</span></p>
<p class="MsoListParagraph" style="text-indent:-.25in"><span style="color:#1F497D"><span style="">2.<span style="font:7.0pt "Times New Roman"">
</span></span></span><span style="color:#1F497D">Perhaps the EGI tool for measuring salt bridges could help, or you could write your own Matlab code to perform cross-channel correlations to look for odd behavior</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D">Good luck with it,</span></p>
<p class="MsoNormal"><span style="color:#1F497D">-Jeff Eriksen</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt; font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt; font-family:"Tahoma","sans-serif""> eeglablist-bounces@sccn.ucsd.edu [mailto:eeglablist-bounces@sccn.ucsd.edu]
<b>On Behalf Of </b>Benz, Heather *<br>
<b>Sent:</b> Friday, November 07, 2014 5:39 AM<br>
<b>To:</b> eeglablist@sccn.ucsd.edu<br>
<b>Subject:</b> [Eeglablist] Old EGI system</span></p>
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<p class="MsoNormal"> </p>
<p class="MsoNormal">We just inherited a barely used EGI system, purchased circa 2009. When we chatted with an EGI rep, he said we’d probably want to send in all of the EEG nets for refurbishment, which of course comes with a price tag. Before we send them
in, I’d like to run a few trial sessions and see how they behave. I can spot really terrible channels by eye, but I’m wondering if there are small-to-medium problems that could have developed with the nets (or any EEG caps in general), which wouldn’t show
up just by watching the data scroll by, that I should be looking out for?</p>
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<p class="MsoNormal">Thanks!</p>
<p class="MsoNormal">Heather</p>
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