<div dir="ltr">Dear Tahani,<div><br></div><div style>Check out SIFT by Tim Mullen</div><div style><a href="http://sccn.ucsd.edu/wiki/SIFT">http://sccn.ucsd.edu/wiki/SIFT</a><br></div><div style><br></div><div style>When you compute coherence measures, it generates EEG.Conn.... you can simply average them across all channels. FYI, averaging across column gives you information outflow, and across raw gives you information inflow.</div>
<div style><br></div><div style>Makoto</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">2013/5/29 T. Almabruk <span dir="ltr"><<a href="mailto:t.almabruk@yahoo.com" target="_blank">t.almabruk@yahoo.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div style="font-size:12pt;font-family:arial,helvetica,sans-serif"><div><span>Hi List</span></div><div><span>I have a question about combining coherence measurement for multi electrodes. I mean If I calculate the coherence between each pair in a dataset of 40 electrodes. Is there any way to combine theses measurements in one measure I need a way better that averaging. or any idea that help me to have just one measurement instead of<var></var> this big number of measurements</span></div>
<div><span></span> </div><div><span>Cheers,</span></div><div><span>Tahani</span></div><div><br></div> <div style="font-family:arial,helvetica,sans-serif;font-size:12pt"> <div style="font-family:times new roman,new york,times,serif;font-size:12pt">
<div dir="ltr"> <div style="margin:5px 0px;padding:0px;border:1px solid rgb(204,204,204);min-height:0px;line-height:0;font-size:0px" readonly></div> <font face="Arial"> <b><span style="font-weight:bold">From:</span></b> Makoto Miyakoshi <<a href="mailto:mmiyakoshi@ucsd.edu" target="_blank">mmiyakoshi@ucsd.edu</a>><br>
<b><span style="font-weight:bold">To:</span></b> T. Almabruk <<a href="mailto:t.almabruk@yahoo.com" target="_blank">t.almabruk@yahoo.com</a>> <br> <b><span style="font-weight:bold">Sent:</span></b> Thursday, April 25, 2013 3:40 AM<br>
<b><span style="font-weight:bold">Subject:</span></b> Re: [Eeglablist] EEG Coherence<br> </font> </div> <div><br><div><div dir="ltr">Dear Tahani,<div><br></div><div>Ok I see. Most likely, the difference between the two results are due to the difference of parameters you used. Unfortunately I'm not familiar nor interested in pop_newcrossf() especially at the scalp channel level-because we have SIFT- I won't compare the details in these two methods.</div>
<div><br></div><div>So I have no answer to your question technically, but starategically I can recommend that you use SIFT instead. It addresses many theoretical problems you run into when performing coherency analysis. Google SIFT Tim Mullen. He is one of our genius guys.</div>
<div><br></div><div>Makoto</div></div><div><br><br><div>2013/4/19 T. Almabruk <span dir="ltr"><<a href="mailto:t.almabruk@yahoo.com" rel="nofollow" target="_blank">t.almabruk@yahoo.com</a>></span><br>
<blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid"><div><div style="font-family:arial,helvetica,sans-serif;font-size:14pt"><div>
<span>Dear Makoto</span></div>
<div><span></span> </div>
<div><span>Thanks alot for your reply. I will try to explain my problem so that may give you an idea about what i am trying to do. Simply i try to make a comparsion between calculating cross-coherence between two channals using first pop-newcrossf() and second by Mscoher.</span></div>
<div><span>I followed the next steps:</span></div>
<div><span>1- I filtered the signals </span></div>
<div style="font-family:arial,helvetica,sans-serif;font-size:19px;font-style:normal;background-color:transparent"><span>2- extract the epoches</span></div>
<div><span>3-run ICA</span></div>
<div><span>4- i used pop_newcrossf() to calculate the cross-coherence between channel CP1(17) and CP2(18) in the first case as can be seen in the attached figures.</span></div>
<div><span></span> </div>
<div><span><a href="http://www.flickr.com/photos/94417587@N05/" rel="nofollow" target="_blank">http://www.flickr.com/photos/94417587@N05/</a> </span></div>
<div><span></span> </div>
<div><span> and then repeated the same steps with channel T7(11) and channel T8 (15).</span></div>
<div><span></span> </div>
<div><span>on the othere hand,</span></div>
<div style="font-family:arial,helvetica,sans-serif;font-size:19px;font-style:normal;background-color:transparent"><span> i calculated the cross-coherence between the same channals by using MSCOHER matlab function, i used the data after extracting epoches but without runing ICA. </span></div>
<div style="font-family:arial,helvetica,sans-serif;font-size:19px;font-style:normal;background-color:transparent"><span></span> </div><span><font face="Courier New"><font face="Courier New">
<div>fs=128; </div></font></font><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New">% sampling frequency</font></font></font></span></div><font face="Courier New"><font face="Courier New">
<div>nfft=256; </div></font></font><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New">% width of subseries (# of samples)</font></font></font></div>
<font face="Courier New"><font face="Courier New">
<div>ww=256; </div></font></font><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New"><font color="#228b22" face="Courier New">% width of hanning window applied to each subseries</font></font></font><font face="Courier New"><font face="Courier New">
<div>over=0;</div>
<div>s_1=EEG.data(11,:);</div>
<div>s_2=EEG.data(15,:);</div></font></font><font face="Courier New"><font face="Courier New">
<div></div>
<div>q=mscohere(s_1,s_2,hanning(ww),over,nfft,fs);</div>
<div></div></font></font><font face="Courier New"><font face="Courier New">
<div>figure</div>
<div></div>
<div></div>
<div>plot(q(1:50),</div></font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'b'</font></font></font><font face="Courier New"><font face="Courier New">);</font></font><font face="Courier New"><font face="Courier New">
<div>ylabel(</div></font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'Coherence'</font></font></font><font face="Courier New"><font face="Courier New">);
<div>xlabel(</div></font></font><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New"><font color="#a020f0" face="Courier New">'Frequences'</font></font></font><font face="Courier New"><font face="Courier New">);</font></font>
<div><font face="Courier New"><font face="Courier New"></font></font> </div>
<div><font face="arial, helvetica, sans-serif" size="3"><b>I can see a difference between the results in both cases i mean the coherence between the channals by using newcross() and that by using Mscoher!!!!</b></font></div>
<div><font face="arial, helvetica, sans-serif" size="3"><b></b></font> </div>
<div><font><font face="arial, helvetica, sans-serif" size="3"><b>I am sure that i still missunderstand something</b></font></font></div>
<div style="font-family:Courier New;font-size:2px;font-style:normal;background-color:transparent"><font><font face="arial, helvetica, sans-serif" size="3"><b>and i'm willing to get help from you</b></font></font></div>
<div style="font-family:Courier New;font-size:2px;font-style:normal;background-color:transparent"><font><font face="arial, helvetica, sans-serif" size="3"><b></b></font></font> </div>
<div style="font-family:Courier New;font-size:2px;font-style:normal;background-color:transparent"><font><font face="arial, helvetica, sans-serif" size="3"><b>Cheers,<var></var></b></font></font></div>
<div style="font-family:Courier New;font-size:2px;font-style:normal;background-color:transparent"><font><font><font face="arial, helvetica, sans-serif" size="3"><b>Tahani</b></font></font></font></div>
<div style="font-family:arial,helvetica,sans-serif;font-size:19px;font-style:normal;background-color:transparent"></div>
<div><br></div>
<div style="font-family:arial,helvetica,sans-serif;font-size:14pt">
<div style="font-family:times new roman,new york,times,serif;font-size:12pt">
<div dir="ltr">
<div style="margin:5px 0px;padding:0px;border:1px solid rgb(204,204,204);line-height:0;font-size:0px;min-height:0px">
</div><font face="Arial"><b><span style="font-weight:bold">From:</span></b> Makoto Miyakoshi <<a href="mailto:mmiyakoshi@ucsd.edu" rel="nofollow" target="_blank">mmiyakoshi@ucsd.edu</a>><br><b><span style="font-weight:bold">To:</span></b> T. Almabruk <<a href="mailto:t.almabruk@yahoo.com" rel="nofollow" target="_blank">t.almabruk@yahoo.com</a>> <br>
<b><span style="font-weight:bold">Cc:</span></b> "<a href="mailto:eeglablist@sccn.ucsd.edu" rel="nofollow" target="_blank">eeglablist@sccn.ucsd.edu</a>" <<a href="mailto:eeglablist@sccn.ucsd.edu" rel="nofollow" target="_blank">eeglablist@sccn.ucsd.edu</a>> <br>
<b><span style="font-weight:bold">Sent:</span></b> Tuesday, April 2, 2013 8:36 AM<br><b><span style="font-weight:bold">Subject:</span></b> Re: [Eeglablist] EEG Coherence<br></font></div><div><div>
<div><br>
<div>
<div dir="ltr">Dear Tahani,
<div><br></div>
<div>Looks like your channel 1 and 2 are very much alike. Did you choose two ICs? Did you choose subspace of alpha or mu that are similar to each other?</div>
<div><br></div>
<div>If there were coherence of near 1 between two ICs that do not belong to the same subspace (and I guess that's the case here), something should be wrong because they are far from independent. Why don't you check the setup and tell us more detail about the comparison?</div>
<div><br></div>
<div>Makoto</div>
<div><br></div>
<div><br></div></div>
<div><br><br>
<div>2013/3/27 T. Almabruk <span dir="ltr"><<a href="mailto:t.almabruk@yahoo.com" rel="nofollow" target="_blank">t.almabruk@yahoo.com</a>></span><br>
<blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">
<div>
<div style="font-family:arial,helvetica,sans-serif;font-size:14pt">
<div><span><br></span></div>
<div><br></div>
<div style="font-family:arial,helvetica,sans-serif;font-size:14pt">
<div style="font-family:times new roman,new york,times,serif;font-size:12pt">
<div>
<div>
<div style="font-family:arial,helvetica,sans-serif;font-size:14pt">
<div>Hi List</div>
<div> </div>
<div>I asked a question before about measuring EEG coherence by EEGLAB. I got benifits from the answer i got but still have something wrong. I applied the function to the same dataset provided with EEGLAB tutorial. i filtered the data first and then extract the epoches (153). After that i run ICA and ploted component cross-coherence between channel 4 and channel 9.</div>
<div>As you can see fig(1) was the result and i tried to zoom it in (fig 2).</div>
<div>I wanted to compare the result with that can be done by matlab function (Mcoher)<var></var> and fig(3) represents<var></var> the results i got.</div>
<div>My question is that, there is a big difference in the coherence's amplitude between the two functions where using EEGLAB the amplitude is less that 0.1 where with Mcohere as you can see is close to 1.</div>
<div> </div>
<div>I'm sure i miss undeerstand something because i'm new with this area and hope i can find some help from you .</div>
<div> </div>
<div>Cheers,</div>
<div>Tahani</div></div></div></div><br><br><a href="http://www.flickr.com/photos/94417587@N05/" rel="nofollow" target="_blank">http://www.flickr.com/photos/94417587@N05/</a></div>
<div style="font-family:times new roman,new york,times,serif;font-size:12pt"> </div>
<div style="font-family:times new roman,new york,times,serif;font-size:12pt"> </div></div></div></div><br>_______________________________________________<br>Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" rel="nofollow" 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" rel="nofollow" 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" rel="nofollow" target="_blank">eeglablist-request@sccn.ucsd.edu</a><br>
</blockquote></div><br><br clear="all"><span class="HOEnZb"><font color="#888888">
<div><br></div>-- <br>
<div dir="ltr">Makoto Miyakoshi<br>Swartz Center for Computational Neuroscience<br>Institute for Neural Computation, University of California San Diego<br></div></font></span></div></div><span class="HOEnZb"><font color="#888888"><br>
<br></font></span></div></div></div></div></div></blockquote><span class="HOEnZb"><font color="#888888">
</font></span></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Makoto Miyakoshi<br>Swartz Center for Computational Neuroscience<br>Institute for Neural Computation, University of California San Diego<br>
</div>
</font></span></div></div><br><br></div> </div> </div> </div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Makoto Miyakoshi<br>Swartz Center for Computational Neuroscience<br>Institute for Neural Computation, University of California San Diego<br>
</div>
</div>