Dear Debnath,<div><br></div><div>I'm not a EMG guy so let me talk about general thing.</div><div>Your approach seems fairly general and ok.</div><div>If you find similar EMG activities in multiple channels ICA would work give you representative ones. It may not gives you better onset detection, but your data will be better addressed anyways.</div>
<div><br></div><div>Makoto<br><br><div class="gmail_quote">2013/3/8 Ranjan Debnath <span dir="ltr"><<a href="mailto:ranjan@psy.otago.ac.nz" target="_blank">ranjan@psy.otago.ac.nz</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Courier New"">Dear EEG Experts<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Courier New"">I was reading old EEGLab archive and found a<span style="color:#1f497d">
</span>post related to my problem. (<a href="http://sccn.ucsd.edu/pipermail/eeglablist/2008/002456.html" target="_blank">http://sccn.ucsd.edu/pipermail/eeglablist/2008/002456.html</a>). I want to make event marker or trigger out of EMG onset time. I want to plot my data EMG
lock. I was visually adding event marker in EEGLab. However, I have read some articles, which reported creating event marker out of EMG onset by algorithm. In reply of the above mentioned post, Brad Voytek also suggested using an algorithmic method for extracting
EMG onsets, “as it's much faster, and less likely to be biased.” Is there any specific program, software or Plugin for extracting EMG onset time?
<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">I have some questions about EMG data processing:<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">I have collected EMG data simultaneously with EEG data. While I visually mark the EMG onset, I process them with rest of 32 channels.
For example, I change the sampling rate, highpass filter and then scroll the data in eegplot() to mark EMG onset. Then I subtract the two EMG channels to further process rest of the channels. Is this appropriate procedure?? Or alternatively, <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">Do I need to
</span><span style="font-size:12.0pt;font-family:"Courier New"">subtract two EMG channels first and then process them separately to find EMG onset time? Then I import the EMG onset file as event marker or trigger in EEGLab GUI.<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">Which of the above process should I follow?? Or should I discard both of them?<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Courier New"">I highly appreciate your suggestions.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">Thanking You
<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New""><u></u> <u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">With Regards<u></u><u></u></span></p>
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<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">Ranjan Debnath<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">Action, Brain and Cognition Lab<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">Department of Psychology<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:justify"><span style="font-size:12.0pt;font-family:"Courier New"">University of Otago<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Courier New"">Dunedin, New Zealand</span><u></u><u></u></p>
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-- <br>Makoto Miyakoshi<br>JSPS Postdoctral Fellow for Research Abroad<br>Swartz Center for Computational Neuroscience<br>Institute for Neural Computation, University of California San Diego<br>
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