<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"Apple Color Emoji";
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
font-size:10.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body lang="DA" link="#0563C1" vlink="#954F72" style="word-wrap:break-word">
<div class="WordSection1">
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US">Hi Alice<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US">This often happen if you have a sparse EEG layout so the neighbouring electrodes a too far away when you define which electrodes are “neighbours”. The solution is to
make sure the frontal electrodes are connected to neighbouring electrodes in the output from ft_prepare_neighbours. You can easily inspect this with ft_neighbourplot (sse example here:
<a href="https://github.com/mcvinding/cluster-stat-workshop/blob/main/tutorial.md#non-parametric-cluster-based-permutation-tests-on-all-channel-data">
https://github.com/mcvinding/cluster-stat-workshop/blob/main/tutorial.md#non-parametric-cluster-based-permutation-tests-on-all-channel-data</a>).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US">To change the neighbour definition, see the options in documentation for ft_prepare_neighbours.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US">Best regards<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US">Mikkel<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm">
<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span lang="EN-GB" style="font-size:12.0pt;color:black">Fra:
</span></b><span lang="EN-GB" style="font-size:12.0pt;color:black">fieldtrip <fieldtrip-bounces@science.ru.nl> på vegne af Milne, Alice via fieldtrip <fieldtrip@science.ru.nl><br>
<b>Dato: </b>torsdag, 6. oktober 2022 kl. 17.00<br>
<b>Til: </b>fieldtrip@science.ru.nl <fieldtrip@science.ru.nl><br>
<b>Cc: </b>Milne, Alice <a.milne@ucl.ac.uk><br>
<b>Emne: </b>[FieldTrip] Cluster Analysis - electrodes not clustering<o:p></o:p></span></p>
</div>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">Hello!</span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US"> </span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">I am running cluster analysis on a really clear effect in fronto-central electrodes when you plot data.
</span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">The cluster analysis identifies these electrodes but is identifying each one as a separate cluster. No two electrodes, even when neighbours are part of the same cluster.
</span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US"> </span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">This is a within subjects effect – 22 subjects and two conditions. I am not sure how this issue could to the cluster analysis settings as they seem quite standard (
and have been used previously in the lab). </span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US"> </span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">I can also plot the topographies etc and the neighbours are all where they should be.
</span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US"> </span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">Has anyone come across this issue before?
</span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US"> </span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">Many thanks for your time
</span><span lang="EN-US" style="font-size:11.0pt;font-family:"Apple Color Emoji";mso-fareast-language:EN-US">😊</span><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">
</span><span lang="EN-GB" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p></o:p></span></p>
</div>
</body>
</html>