<div dir="ltr"><div><div><div>Hello, Steve,<br><br></div>Thank you very much for your replying.<br><br></div><div>I used ICA implemented in EEGLAB to remove the artefact. I removed the bad channels before ICA and interpolated them after artefact rejection. As you said, I must interpolate bad channels before average referencing. I think the only time to re-reference is after artefact rejection by ICA and interpolation of bad channels, which is almost the last step of my preprocessing. Does it sound OK?<br></div>By the way, during the recording, we put the reference electrode on left mastoids.<br><br></div><div>Best<br></div>Bin<br></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="ltr"><div>
<div><span style="color:rgb(11,83,148)"><font face="arial,helvetica,sans-serif" size="1">++++++++++++++++++++++++++++++<br></font></span></div><span style="color:rgb(11,83,148)"><font>Bin Wang<br>Cognitive Neuroscience<br>Institute of Neuroscience and Medicine (INM-3)<br>Forschungszentrum Juelich, <br>Leo-Brandt-Str. 5<br></font></span></div><div><span style="color:rgb(11,83,148)"><font>52425 Juelich<span style="color:rgb(11,83,148)"><font><font face="Arial"><br></font></font></span>Email: <a href="mailto:binwang87828@gmail.com" target="_blank">b.wang@fz-juelich.de</a><br></font></span><span style="color:rgb(11,83,148)"><font><span style="color:rgb(11,83,148)"><font><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="DE"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="DE"> & </span></span></font></span><a href="mailto:binwang87828@gmail.com" target="_blank">binwang87828@gmail.com</a></font></span><span style="color:rgb(11,83,148)"><font><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="DE"><br></span></font></span><span style="color:rgb(11,83,148)"><font><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="DE"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="DE"></span></span>Telefon: 02461-61-9542
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<br><div class="gmail_quote">On Tue, Dec 2, 2014 at 2:51 AM, Stephen Politzer-Ahles <span dir="ltr"><<a href="mailto:spa268@nyu.edu" target="_blank">spa268@nyu.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">Hello Bin,<div><br></div><div>If you have bad channels that need to be interpolated, this must be done before average referencing (see previous messages on the list about this issue).</div><div>I also suspect that referencing may need to be done before artifact rejection, depending on how you do artifact rejection, because some of the methods will be affected by your choice of reference. For example, if you reject based on extreme values (and apply this to all channels), you can imagine a situation where a given channel might not exceed the value if the reference is e.g. Cz but might change to exceed the value once the reference is changed to e.g. mastoids. Ultimately, whether or not this is an issue will depend on how you plan on doing artifact rejections, and properties of your system (e.g., whether you have bipolar EOGs that use their own reference separate from the rest of the electrodes).</div><div><br></div><div>There may also be other issues that I haven't thought of here, others on the list may be able to clarify more.</div><div><br></div><div>Best,</div><div>Steve</div></div><div class="gmail_extra"><br clear="all"><div><div><div dir="ltr"><div><br><br></div>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><br></div></div></div>
<br><div class="gmail_quote"><div><div class="h5">On Sun, Nov 30, 2014 at 6:48 PM, Bin Wang <span dir="ltr"><<a href="mailto:binwang87828@gmail.com" target="_blank">binwang87828@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div style="word-wrap:break-word"><div>Dear all,</div><div><br></div><div>One simple question: I would like to try several different reference selections (i.e. average or mastoid), hopefully, I can find a relatively better one. My question is if the re-reference step must be done before epoch the data and artefact removal. Because I want to do all of preprocessing steps and artefact removal, and then apply several different re-reference selections, by this way I don’t need to do all of preprocessing steps again. Does it sound fine? Is there any other artefacts or problems that will be induced by the re-reference of last step.</div><div><br></div><div>I am looking forward your any advices<br><br></div><div>Thank you in advance,<br><br></div><div>Bin</div><div><br></div><div>
<div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><font color="#0B5394" face="arial,helvetica,sans-serif" size="1">++++++++++++++++++++++++++++++</font><font color="#0B5394" face="arial,helvetica,sans-serif" size="1"><br></font><span style="font-family:Tahoma;font-size:13px"></span><div style="font-family:Tahoma;font-size:13px"><font color="#0B5394">Bin Wang</font><font color="#0B5394"><br>Cognitive Neuroscience</font><font color="#0B5394"><br>Institute of Neuroscience and Medicine (INM-3)</font><font color="#0B5394"><br>Forschungszentrum Juelich, </font><font color="#0B5394"><br>Leo-Brandt-Str. 5 </font><font color="#0B5394"><br>52425 Juelich</font><font color="#0B5394" face="arial"><br></font><font color="#0B5394">Email: </font><a href="https://webmail.fz-juelich.de/owa/redir.aspx?C=hswxAlx8wU6cP189jFS_1w0PFSKb8dAIIkV6dqtR-VUUMNMIisKisV7RZADeuZK3wPR2w27Q5yU.&URL=mailto%3abinwang87828%40gmail.com" target="_blank"><font>b.wang@fz-juelich.de</font></a><font color="#0B5394"><br> </font><font color="#1F497D" face="Calibri,sans-serif"><span style="font-size:11pt" lang="de">&</span></font><font color="#0B5394"> </font><a href="https://webmail.fz-juelich.de/owa/redir.aspx?C=hswxAlx8wU6cP189jFS_1w0PFSKb8dAIIkV6dqtR-VUUMNMIisKisV7RZADeuZK3wPR2w27Q5yU.&URL=mailto%3abinwang87828%40gmail.com" target="_blank"><font>binwang87828@gmail.com</font></a><a href="https://webmail.fz-juelich.de/owa/redir.aspx?C=hswxAlx8wU6cP189jFS_1w0PFSKb8dAIIkV6dqtR-VUUMNMIisKisV7RZADeuZK3wPR2w27Q5yU.&URL=mailto%3abinwang87828%40gmail.com" target="_blank"><font><font color="#1F497D" face="Calibri,sans-serif"><span style="font-size:11pt" lang="de"> </span></font></font></a><font color="#0B5394"><br></font><font color="#0B5394">Telefon: 02461-61-9542</font><div><font color="#0B5394" face="arial,helvetica,sans-serif" size="1">++++++++++++++++++++++++++++++</font></div></div></div><br></div><br><br>
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