<div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:x-small">Dear Eric, you asked for literature recommendation explaining the utility of average referencing. I suggest the book 'Electric Fields of the Brain'.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Oct 4, 2014 at 2:50 AM, Simon Finnigan <span dir="ltr"><<a href="mailto:finnigan.simon@gmail.com" target="_blank">finnigan.simon@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto"><div>Hi All</div><div><br></div><div>Firstly I must say that as a scientist, I find the rationale from Jason via Makoto to be un-scientific and unsatisfactory.</div><div><br></div><div><span>Second - </span><span style="background-color:rgba(255,255,255,0)">This will only partly answer your question I think, but here goes: it all depends on how you're analysing your data [what you're looking at/for] and particularly, whether or not scalp topographies are of interest to you - but in general and in brief, the consensus seems to be that common-average referencing is preferable over mastoid referencing, at least - and probably other references sites too [e.g. vertex; nasion]. [Also are your data referenced to one or both mastoids? and if both - were they linked, or averaged together after recording?]</span><div><span style="background-color:rgba(255,255,255,0)"><br></span></div><div><span style="background-color:rgba(255,255,255,0)">My 2002 paper in 'Neuropsychologia' addressed this issue scientifically, at least in part - e.g. see final figure [albeit we weren't doing ICA back then either!].</span></div><div><span style="background-color:rgba(255,255,255,0)"><br></span></div><div><span style="background-color:rgba(255,255,255,0)">Regards, Simon</span></div></div><div><span style="background-color:rgba(255,255,255,0)"><br></span></div><div><br>On 04/10/2014, at 8:21, Makoto Miyakoshi <<a href="mailto:mmiyakoshi@ucsd.edu" target="_blank">mmiyakoshi@ucsd.edu</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr">Here is update.<div>I asked the question to Jason. He told me that t<span style="color:rgb(0,0,0);font-family:Calibri,sans-serif;font-size:14.8571424484253px">he main reason avg reference is useful is that it returns brain maps that look like nice localized sources inside the head with red blob and slight negative (aqua/green) background. This makes sense.</span></div><div><br></div><div><span style="color:rgb(0,0,0);font-family:Calibri,sans-serif;font-size:14.8571424484253px">Makoto</span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Oct 2, 2014 at 10:00 AM, Makoto Miyakoshi <span dir="ltr"><<a href="mailto:mmiyakoshi@ucsd.edu" target="_blank">mmiyakoshi@ucsd.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">Dear Eric,<div><br></div><div>I have the same question for long time. In my case, because I run ICA and remain in IC analysis and almost never come back to channels, I really wonder if I need re-referencing at all.</div><div><br></div><div>I've heard Jason Palmer, who wrote AMICA for EEGLAB, say average reference before ICA is necessary, but he did not give me a clear explanation for that. Scott wanted to know it too, but we were interrupted at that time. Next time I'll ask it to him (when I ever see him in the lab...)</div><div><br></div><div>Makoto </div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div>On Tue, Sep 30, 2014 at 2:44 PM, Eric HG <span dir="ltr"><<a href="mailto:erichg2013@gmail.com" target="_blank">erichg2013@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><div dir="ltr">Dear list,<div><br></div><div>I have read the tutorial on the site and it says: "<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px">Converting data, before analysis, from fixed or common reference (for example, from a common earlobe or other channel reference) to 'average reference' is advocated by some researchers, particularly when the electrode montage covers nearly the whole head (as for some high-density recording systems)." </span></div><div><span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px"><br></span></div><div><font color="#000000" face="sans-serif"><span style="line-height:19px">I have data collected with a mastoid reference and I was wondering in which cases it would be considered best to rereference to the average? Are there any specific papers about rereferencing that anyone would recommend?</span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19px"><br></span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19px">Regards,</span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19px"><br></span></font></div><div><font color="#000000" face="sans-serif"><span style="line-height:19px">Eric </span></font></div></div>
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