<div dir="ltr">Dear Luisa,<div><br></div><div>Update EEGLAB to the latest version. I remember we had a temporary issue of head plot a few years ago, and this may be it...</div><div><br></div><div>I'm worried about the blank ERP image. It should be unrelated to the scalp map issue.</div>
<div><br></div><div>As a general advice, you should record as many channels as possible (up to 128). Even if your interest is in the motor cortex only, you should have whole scalp coverage for good ICA results. Remember, cortical patch activity always create an equivalent dipole that has 8-shape projection pattern. ICA not only catches the projection of the short pathway (which you assume 'the source is right <i>under</i> the channel') but also catches the polarity-inversed long pathway on the otherside of the head, which is why IC scalp maps have positives and negatives. In other word, if you have nice focal positivity near motor cortex, that should be accompanied by the huge surrounding negativity because of dipolar (i.e. 8-shaped) projection, and both are equally important.</div>
<div><br></div><div>Makoto</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">2014-05-14 22:27 GMT-07:00 Luisa Roeder <span dir="ltr"><<a href="mailto:l.roeder@qut.edu.au" target="_blank">l.roeder@qut.edu.au</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:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Thanks, Steve, for your reply.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Yes, that is what I thought re the ICA amplitude per trial plot…<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Re the head maps, I thought there may be another analysis approach; e.g. instead of rejecting components based on maps doing it somehow differently…<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Cheers<u></u><u></u></span></p><div class="">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Luisa<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black">Luisa Roeder</span></b><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black"> <b>| PhD researcher | Movement Neuroscience Program</b></span><span style="font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black">Institute of Health and Biomedical Innovation & School of Exercise and Nutrition Science</span><span style="font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black">Queensland University of Technology | 60 Musk Ave, Kelvin Grove, Brisbane, QLD 4059, Australia.</span><span style="font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
</div><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black">t:</span></b><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black"> 07 3138 6428 |<b> m:</b> 0427 469 478 |
<b>e: <a href="mailto:l.roeder@qut.edu.au" target="_blank">l.roeder@qut.edu.au</a> </b></span><span style="font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p><div class="">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black">w:</span></b><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:black">
<b><a href="http://www.ihbi.qut.edu.au/about/researchover/injury/movementNeuroscience.jsp" target="_blank"><span style="color:black">www.ihbi.qut.edu.au/about/researchover/injury/movementNeuroscience.jsp</span></a>
</b></span><span style="font-family:"Calibri","sans-serif";color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:black">CRICOS No. 00213J</span><span style="font-family:"Calibri","sans-serif";color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
</div><p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:politzerahless@gmail.com" target="_blank">politzerahless@gmail.com</a> [mailto:<a href="mailto:politzerahless@gmail.com" target="_blank">politzerahless@gmail.com</a>]
<b>On Behalf Of </b>Stephen Politzer-Ahles<br>
<b>Sent:</b> Thursday, 15 May 2014 1:17 PM<br>
<b>To:</b> Luisa Roeder<br>
<b>Cc:</b> <a href="mailto:eeglablist@sccn.ucsd.edu" target="_blank">eeglablist@sccn.ucsd.edu</a><br>
<b>Subject:</b> Re: [Eeglablist] removing ICA components<u></u><u></u></span></p><div><div class="h5">
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal">Hello Luisa,<u></u><u></u></p>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
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<div>
<p class="MsoNormal">As for the top right panel of that plot, what that plots is the ICA's amplitude per trial, and the ERP. So I imagine you can't get those when you're not using epoched data (although I haven't tried myself). <u></u><u></u></p>
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<div>
<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">I'm not sure about the issue with the head maps; my hunch is that it might not be possible to get good topoplots without more channels, but hopefully someone else more familiar with that issue can give you some more input.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Best,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">Steve<u></u><u></u></p>
</div>
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<p class="MsoNormal"><br clear="all">
<u></u><u></u></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><u></u> <u></u></p>
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<p class="MsoNormal">Stephen Politzer-Ahles<br>
New York University, Abu Dhabi<br>
Neuroscience of Language Lab<br>
<a href="http://www.nyu.edu/projects/politzer-ahles/" target="_blank">http://www.nyu.edu/projects/politzer-ahles/</a><u></u><u></u></p>
</div>
</div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><u></u> <u></u></p>
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<p class="MsoNormal">On Thu, May 15, 2014 at 3:37 AM, Luisa Roeder <<a href="mailto:l.roeder@qut.edu.au" target="_blank">l.roeder@qut.edu.au</a>> wrote:<u></u><u></u></p>
<div>
<div>
<p class="MsoNormal">Hi all,<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">I have been following the EEGLAB discussion list for a few weeks now and have been working through most of the tutorials and wiki pages but I am still a newbie to MATLAB, EEGLAB
and analysing EEG signals in general. Hence, I have basic, newbie questions which I hope you can help me with.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal" style="margin-left:36.0pt;text-autospace:none">
I am trying to follow the analysis steps that are outlined in this paper: <span style="font-size:9.0pt;font-family:"Segoe UI","sans-serif"">
Petersen, T.H., M. Willerslev-Olsen, B.A. Conway, and J.B. Nielsen, <i>The motor cortex drives the muscles during walking in human subjects.</i> The Journal of physiology, 2012.
<b>590</b>(Pt 10): p. 2443-52.</span><u></u><u></u></p>
<p class="MsoNormal"><a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=1.%09Petersen%2C+T.H.%2C+M.+Willerslev-Olsen%2C+B.A.+Conway%2C+and+J.B.+Nielsen%2C+The+motor+cortex+drives+the+muscles+during+walking+in+human+subjects.+The+Journal+of+physiology%2C+2012.+590%28Pt+10%29%3A+p.+2443-52" target="_blank">http://www.ncbi.nlm.nih.gov/pubmed/?term=1.%09Petersen%2C+T.H.%2C+M.+Willerslev-Olsen%2C+B.A.+Conway%2C+and+J.B.+Nielsen%2C+The+motor+cortex+drives+the+muscles+during+walking+in+human+subjects.+The+Journal+of+physiology%2C+2012.+590%28Pt+10%29%3A+p.+2443-52</a>.
<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">At the moment I am looking at a continuous dataset that contains 6 EEG and 6 EMG channels and that was recorded during a sustained muscle contraction of the leg. Eventually I also
want to look at gait data but I am not there yet. <u></u><u></u></p>
<p class="MsoNormal">As outlined in the paper, I am trying to perform ICA (runica) on the EEG channels. After I ran the ICA, I want to remove unwanted components (in the gui) via Tools->reject data
using ICA-> reject components by map. However, since I only recorded 6 channels (C3, Cz, C4, F3, Fz, F4) the head maps I receive only cover the region between the 6 electrodes but not the whole head. Also, when clicking on one component the top right panel
that is supposed to show the activity of the component is empty<span style="color:#1f497d">.
</span><u></u><u></u></p>
<p class="MsoNormal">Here is a link to 2 images:
<span style="color:#1f497d"><a href="https://www.dropbox.com/sh/t5b8kmb9b9ce93e/AAC5VyeSEQbob0PTSiSZ61Ita" target="_blank">https://www.dropbox.com/sh/t5b8kmb9b9ce93e/AAC5VyeSEQbob0PTSiSZ61Ita</a>
</span><u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">This does not provide sufficient information to be able to judge whether to keep or to discard a component.
<u></u><u></u></p>
<p class="MsoNormal">What can I do to fix the problem? Is there another/better/more appropriate way to remove artefacts from my data than this approach? Or is the only way recording more channels (32+?)
so that I can plot sufficient head maps?<u></u><u></u></p>
<p class="MsoNormal">Currently I use MATLAB R2012a and EEGLAB v10.2.5.8b.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Thanks so much in advance for your help!!<u></u><u></u></p>
<p class="MsoNormal">Kind regards<u></u><u></u></p>
<p class="MsoNormal">Luisa<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;color:black">Luisa Roeder</span></b><span style="font-size:10.0pt;color:black"> <b>| PhD researcher | Movement Neuroscience Program</b></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:black">Institute of Health and Biomedical Innovation & School of Exercise and Nutrition Science</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;color:black">Queensland University of Technology | 60 Musk Ave, Kelvin Grove, Brisbane, QLD 4059, Australia.</span><u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;color:black">t:</span></b><span style="font-size:10.0pt;color:black">
<a href="tel:%2B61%207%C2%A03138%206428" target="_blank">+61 7 3138 6428</a> |<b> e:
<a href="mailto:l.roeder@qut.edu.au" target="_blank">l.roeder@qut.edu.au</a> </b>
</span><u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;color:black">w:</span></b><span style="font-size:10.0pt;color:black">
<b><a href="http://www.ihbi.qut.edu.au/about/researchover/injury/movementNeuroscience.jsp" target="_blank"><span style="color:black">www.ihbi.qut.edu.au/about/researchover/injury/movementNeuroscience.jsp</span></a>
</b></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:9.0pt;color:black">CRICOS No. 00213J</span><u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
</div>
</div>
<p class="MsoNormal"><br>
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<p class="MsoNormal"><u></u> <u></u></p>
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</div>
<br>_______________________________________________<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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