<div dir="ltr"><div><div>Dear Makoto, <br><br></div>thanks for your response. Yes I agree with you one should avoid to include facial channels from average signal in order to have a clean eeg. Actually my concern was about having a clean EMG signal. They say that recording monopolar EMG instead of bipolar EMG could add some noise to the EMG signal, this is probably due to the distance between the the electrodes? Is there any offline procedure I can use to correct it?<br>
<br></div>Thank you very much,<br><br>Serena<br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On 21 January 2014 23:05, Makoto Miyakoshi <span dir="ltr"><<a href="mailto:mmiyakoshi@ucsd.edu" target="_blank">mmiyakoshi@ucsd.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Dear Maria,<div class="im"><div><br></div><div>> I read this could add some noise to the signal but it is not completely clear to me why this would happen and which offline procedure I could use to improve the SNR.<br>
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<div class="gmail_extra"><br></div></div><div class="gmail_extra">I wonder why, too.</div><div class="gmail_extra">I can think of only one possible case: when you run average referencing. If you don't exclude the facial channels, you may introduce EMG into scalp channels. You may want to exclude facial channels from those with which average reference is computed.</div>
<div class="gmail_extra"><br></div><div class="gmail_extra">I'd like to know whether there are other factors we need to consider...</div><div class="gmail_extra"><br></div><div class="gmail_extra">Makoto<br><br><div class="gmail_quote">
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2014/1/20 Maria Serena Panasiti <span dir="ltr"><<a href="mailto:m.serenapanasiti@gmail.com" target="_blank">m.serenapanasiti@gmail.com</a>></span><br></div></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
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<div dir="ltr"><div><div>Dear List,<br><br></div>we are setting up an experiment in which we would like to simultaneously record EEG and facial EMG. Unfortunately at the moment we just have monopolar amplifiers so we were wondering if it was actually possible to measure a clean EMG activity by using monopolar electrodes (with cephalic ground and reference) and by then offline subtracting the two channels. I read this could add some noise to the signal but it is not completely clear to me why this would happen and which offline procedure I could use to improve the SNR.<br>
<br></div><div>Any help would be very much appreciated!<br><br></div><div>Best wishes,<br><br></div><div>Serena<span><font color="#888888"><br clear="all"></font></span></div><span><font color="#888888"><div>
<div><div><div><div><br>-- <br>Maria Serena Panasiti, Ph.D<br><font color="#222222" face="'times new roman', serif"><span style="font-size:15px;line-height:14px"><br>
</span></font><div><font face="arial, helvetica, sans-serif">Cognitive Social and Affective Neuroscience Lab<br>Department of Psychology.<br>University of Rome "La Sapienza".<br>Via dei Marsi 78 - 00185 - Roma.<br>
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-- <br><div dir="ltr">Makoto Miyakoshi<br>Swartz Center for Computational Neuroscience<br>Institute for Neural Computation, University of California San Diego<br></div>
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</blockquote></div><br><br clear="all"><br>-- <br>Maria Serena Panasiti, Ph.D<br><font color="#222222" face="'times new roman', serif"><span style="font-size:15px;line-height:14px"><br></span></font><div><font face="arial, helvetica, sans-serif">Cognitive Social and Affective Neuroscience Lab<br>
Department of Psychology.<br>University of Rome "La Sapienza".<br>Via dei Marsi 78 - 00185 - Roma.<br>Phone: (+39) 06-49917635. Fax: (+39) 06-49917635</font></div><div><font face="arial, helvetica, sans-serif"><br>
</font></div><div><font face="arial, helvetica, sans-serif"><span>School of Psychology & Clinical Language Sciences</span><br><span>University of Reading <br>Reading, United Kingdom</span> </font>
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