<div dir="ltr"><div class="gmail_default" style="color:#333399">Hello, some quick thoughts below. Thanks for letting the list know of your eventual resolution so that other users can benefit from your experiences.</div><div class="gmail_default" style="color:#333399"><br></div><div class="gmail_default" style="color:#333399">*********************************</div><div class="gmail_default" style="color:#333399">*For issues with importing channels, check that you are using the correct importer function by testing importing with the various importing functions in eeglab, and examining the data/channels after import to see if any of them work correctly.</div><div class="gmail_default" style="color:#333399"><br></div><div class="gmail_default" style="color:#333399">*to be 100% sure that you have your channel locations correct (which is critical for further processing and ICA), just try to make sure all the channels are imported from the original file, and then Edit>Channel Locations, and import the correct/full channel file list from your cap vendor (build one if you need to from scratch, and/or append one with your extra channels). You need to be 100% sure (by checking the channel locations and visualizing them in 2D and 3D) that the locations are correct for all your channels relative to the actual recording cap you used.</div><div class="gmail_default" style="color:#333399"><br></div><div class="gmail_default" style="color:#333399">*google eeglablist + your topic for past questions/responses regarding biosemi channels, about importing/building your channel locations, and about adding/modifying channels/labels.</div><div class="gmail_default" style="color:#333399"><br></div><div class="gmail_default" style="color:#333399">*test out for yourself how selecting a different reference "initial channel" changes the data. I think eeglab is just asking so that it knows which channel to label as ref, but it should be impacting processing after that. as far as I remember, you should be able to reset the reference "after" the basic import has been done, regardless of what you tell eeglab upon import. Also, look through the documentation on the importer function that you are using, there may be extra flags/settings you can use. </div><div class="gmail_default" style="color:#333399"><br></div><div class="gmail_default" style="color:#333399">*double check with Biosemi that the following is really true, as it sounds that you are using saying that Biosemi records without a reference: "<span style="font-family:Calibri,sans-serif;font-size:14.6667px;color:rgb(34,34,34)">BioSemi does not require a reference choice for recording data".</span></div><div class="gmail_default" style="color:#333399"><br></div><div class="gmail_default" style="color:#333399">*remember that many researchers don't included EOG for their ICA, so make sure you are following guidelines from high-quality published articles on your topic (did those researchers keep EOG channels in their ICA analysis). After all, blink-related ICs should show up without the inclusion of EOG channels in your ICA.</div><div class="gmail_default" style="color:#333399">***************************************</div><div class="gmail_default" style="color:#333399"><br></div><div class="gmail_default" style="color:#333399"><br></div></div><br><div class="gmail_quote"><div dir="ltr">On Thu, Nov 29, 2018 at 2:41 AM Bert Vandenberghe <<a href="mailto:b.vandenberghe@kuleuven.be">b.vandenberghe@kuleuven.be</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="EN-US" link="#0563C1" vlink="#954F72">
<div class="m_-2977013195818807843WordSection1">
<p class="MsoNormal">Hello <u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I use BioSemi ActiTwo System 64 electrodes + 6 additional channels (EOG1 -> EOG6), i.e., 2 horizontal eye channels, 2 vertical eye channels and 2 mastoid channels in order to record EEG data in the domain of ERP research about language
learning, focusing mainly on N400 and P600 components.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">After having ran a pilot study, I have some questions.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="m_-2977013195818807843MsoListParagraph"><u></u><span>-<span style="font:7.0pt "Times New Roman"">
</span></span><u></u>When adding channel locations, EEGLAB does not seem to be able to add channel locations to the six EOG channels. However, they are labeled/recognized correctly in the channel plots etc. Is this a detrimental issue for subsequent preprocessing
of EEG, e.g., for ICA analysis? So far, I added the four eye channels in the ICA, ignored the warning message, but now, I doubt whether that was correct practice ?<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="m_-2977013195818807843MsoListParagraph"><u></u><span>-<span style="font:7.0pt "Times New Roman"">
</span></span><u></u>BioSemi does not require a reference choice for recording data. However, EEGLAB requires to choose a reference channel when importing data. Is the choice of this channel completely “free”. In other words, does it make a difference whether
I choose Cz, Pz ,the left mastoid or any other channel for importing data ?Or is it better not to choose a reference channel for importing data that is a site of interest, e.g., Cz in the case language-related experiments. In both cases, I will anyhow re-reference
to the average of scalp channels in order to follow research practice in my domain.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Thanks for your advice on both issues,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Bert<u></u><u></u></p>
</div>
</div>
_______________________________________________<br>
Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" rel="noreferrer" target="_blank">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>
To unsubscribe, send an empty email to <a href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu" target="_blank">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>
For digest mode, send an email with the subject "set digest mime" to <a href="mailto:eeglablist-request@sccn.ucsd.edu" target="_blank">eeglablist-request@sccn.ucsd.edu</a></blockquote></div>