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</o:shapelayout></xml><![endif]--></head><body lang=KO link=blue vlink=purple><div class=WordSection1><p class=MsoNormal style='word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>Yes, I read Dong et al</span><span style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>’<span lang=EN-US>s paper published in Frontiers in Neuroscience (2017). In the paper, the REST EEG was expressed in two equations<o:p></o:p></span></span></p><p class=MsoListParagraph style='margin-left:38.0pt;mso-para-margin-left:0gd;text-indent:-18.0pt;mso-list:l0 level1 lfo1;word-break:break-hangul'><![if !supportLists]><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'><span style='mso-list:Ignore'>(1)<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>V_REST = R_AR * V_AR<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:38.0pt;mso-para-margin-left:0gd;text-indent:-18.0pt;mso-list:l0 level1 lfo1;word-break:break-hangul'><![if !supportLists]><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'><span style='mso-list:Ignore'>(2)<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>V_REST = V_AR + l*average(V_REST)<o:p></o:p></span></p><p class=MsoNormal style='word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>, where the V_REST in (2) was calculated by using (1). At first, I assumed that (1) was enough to get V_REST, but now I figured out that (2) was used to get better approximation of V_REST. I will check whether my leadfield was calculated properly. The 2<sup>nd</sup> term in (2), i.e., l*average(V_REST), was order of 10^(-20), which was why my V_AR and V_REST were almost the same. Maybe I messed up with some unit conversions. Wish me luck!<o:p></o:p></span></p><p class=MsoNormal style='word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>All the best,<o:p></o:p></span></p><p class=MsoNormal style='word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>Min-Young<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph;text-autospace:none;word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>Min-Young Kim, Ph.D.<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph;text-autospace:none;word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>Tel: +82) 42 - 868 - 5204 (Office)<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph;text-autospace:none;word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>Email: <a href="mailto:mykim@kriss.re.kr"><span style='color:#0563C1'>mykim@kriss.re.kr</span></a><o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph;text-autospace:none;word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>Quantum Technology Institute<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph;text-autospace:none;word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'>Korea Research Institute of Standards and Science<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='word-break:break-hangul'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> fieldtrip [mailto:fieldtrip-bounces@science.ru.nl] <b>On Behalf Of </b>Schoffelen, J.M. (Jan Mathijs)<br><b>Sent:</b> Wednesday, October 21, 2020 4:49 PM<br><b>To:</b> FieldTrip discussion list <fieldtrip@science.ru.nl><br><b>Subject:</b> Re: [FieldTrip] EEG rereferencing with REST method<o:p></o:p></span></p></div></div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Hi Min-Young, <o:p></o:p></span></p><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Did you check the original paper that is referenced in the code? I suggest to start there.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Also, re-referencing to the average is achieved by <b>subtraction</b> of the mean over channels, i.e. : data - mean(data)<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>The line you refer to is <b>adding</b> the mean of some variable (data_z) to data, which is not average rereferencing.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Best wishes,<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Jan-Mathijs<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><div><p class=MsoNormal><span lang=EN-US><br><br><o:p></o:p></span></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal><span lang=EN-US>On 21 Oct 2020, at 04:06, Min-Young Kim <<a href="mailto:mykim@kriss.re.kr">mykim@kriss.re.kr</a>> wrote:<o:p></o:p></span></p></div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><div><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Dear FieldTrippers,<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'> <o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>I am working with 19 Ch EEG data acquired with Biosemi system. To test re-reference options, I tried average earlobes, common average, and REST methods in the preprocessing. However, I found that the EEG for REST was almost the same as the EEG for common average. When I looked at the ft_preproc_rereference.m, the line 141 says<span class=apple-converted-space> </span><o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>>>data_z = G * pinv(Gar, 0.05) * data;<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>But then in line 144<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>>>data_z = data + repmat(mean(data_z), size(G,1), 1);<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'> <o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Isn</span><span style='font-size:10.0pt;font-family:"맑은 고딕"'>’<span lang=EN-US>t the line 141 enough to generate REST EEG signals? To me, the line 144 seems to be the common average referenced EEG data. I would appreciate if someone explains the meaning of the line 144.<o:p></o:p></span></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'> <o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Thanks,<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Min-Young<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'> <o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Min-Young Kim, Ph.D.<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Tel: +82) 42 - 868 - 5204 (Office)<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Email:<span class=apple-converted-space> </span></span><span lang=EN-US><a href="mailto:mykim@kriss.re.kr"><span style='font-size:10.0pt;font-family:"맑은 고딕";color:#954F72'>mykim@kriss.re.kr</span></a></span><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'><o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Quantum Technology Institute<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'>Korea Research Institute of Standards and Science<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-justify:inter-ideograph'><span lang=EN-US style='font-size:10.0pt;font-family:"맑은 고딕"'> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.5pt;font-family:"Helvetica",sans-serif'>_______________________________________________<br>fieldtrip mailing list<br></span><span lang=EN-US><a href="https://mailman.science.ru.nl/mailman/listinfo/fieldtrip"><span style='font-size:10.5pt;font-family:"Helvetica",sans-serif;color:#954F72'>https://mailman.science.ru.nl/mailman/listinfo/fieldtrip</span></a></span><span lang=EN-US style='font-size:10.5pt;font-family:"Helvetica",sans-serif'><br></span><span lang=EN-US><a href="https://doi.org/10.1371/journal.pcbi.1002202"><span style='font-size:10.5pt;font-family:"Helvetica",sans-serif;color:#954F72'>https://doi.org/10.1371/journal.pcbi.1002202</span></a><o:p></o:p></span></p></div></blockquote></div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></div></body></html>