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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">1. The relation between an event and EEG may be very complex. Breathing must be very complex. First there will be factors influencing (starting/doing) the activity
of breathing. It may sometimes have a clear cortical relation, but usually more subcortical/spinal. Then of course the breathing produces muscle and movement artefacts. Then the slight changes in pO2 will change the EEG. So you have coherent activity before,
at the same time and after the breathing. Any of these may have a variable response in the EEG both in time and between patients.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">2. Differential amplifiers have both GND and REF. REF is directly part of your EEG-signal and is the one to care about. In a REF-montage a channel shows the
voltage difference between the active electrode and REF. The average is as the name says the average of all (most) channels: avg=sum(chani-ref)/(number of channels). This may be written: sum(chani)/(number of channels)-ref. So rereference to avg would be:
(chan-ref)- (avg-ref) -> chan -avg. The ref is not in the montage any more. <o:p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Pål<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Arial","sans-serif";color:navy">Denne meldingen inneholder ikke sensitiv informasjon som bryter med Rikshospitalets krav til informasjonssikkerhet.</span><span style="color:#1F497D">
<br>
</span><span style="font-size:7.5pt;font-family:"Arial","sans-serif";color:navy">(In compliance with the Security Policy of Rikshospitalet , the content of this message (including any attachments) is of a non-sensitive nature)</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">Fra:</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>På vegne av</b> ida miokovic<br>
<b>Sendt:</b> 17. juni 2013 13:50<br>
<b>Til:</b> EEGLAB List<br>
<b>Emne:</b> [Eeglablist] relation between EEG data and other signal, average ref question<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Dear list,</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">I have 2 questions which I will try to present as clear as I can and to thank you in advance for any help:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">1. I am trying to find relation (causal connection) between EEG dataset and certain breathing signal (let's say it is B signal) recorded at the same time as EEG.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""> I performed EEG data preprocessing (filtering, ICA and removal of components recognized as artifacts).<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""> So on one side I have continuous signal of EEG channels and on the other side continuous signal B (of the same size as EEG channels recording). What are the best ways to perform
this in EEGLAB? I suppose everyone is always trying to find certain relation between something and EEG signals so I suppose it is not unusual request. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">2. This question is about re-referencing to the average reference - EEG dataset I am working with has been recorded with AFz as GND and FCz as REF (128 chennels Acti Cap is
used). Nothing from these channels isn't present in data I have (I did not participate in recording procedure) and I would like to re-reference data to the average reference. Is it usual that activity from REF and GND channels are not given/measured? In tutorial
of EEGLAB, I found suggestion to include reference channels in the average reference if they are on the scalp. Mine are on the scalp, but I don't have any recordings of them. Also, everyone is mentioning REF electrode, and I have GND too...<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Kind regards and thank you for your time and help<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Ida<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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