<html xmlns:v="urn:schemas-microsoft-com:vml" 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 12 (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:Verdana;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:"Bitstream Vera Sans";
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
span.apple-style-span
{mso-style-name:apple-style-span;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Verdana","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:612.0pt 792.0pt;
margin:70.85pt 70.85pt 70.85pt 70.85pt;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=NL link=blue vlink=purple style='word-wrap: break-word;-webkit-nbsp-mode: space;
-webkit-line-break: after-white-space'>
<div class=Section1>
<div>
<p class=MsoNormal><span style='color:#1F497D'>Dear Jonas,<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>here comes a question concerning
the wonderful stats function<o:p></o:p></p>
</div>
<div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><span class=apple-style-span>depsampregrT</span><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><span class=apple-style-span>I am
using it mainly for running time–frequency–electrode cluster tests. I usually
use contrasts like cfg.contrastcoefs=[-3 -1 1 3] and it has proven
pretty powerful.</span><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>With a new data set, I sadly have
only three levels of data, which is of course always a bit of a pain for linear
contrasts.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>What puzzles me is that<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>[-2 -1 3] (i.e., linear increase;
trying to keep it zero-weighted)<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>and <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>[-1 2 -1] (i.e. trying to
crudely model an inverse u-shape relationship)<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>give the very same result (not
exactly numerically, but very much in terms of clusters, down to very
similar p-values, etc).<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>Q: Any idea why this might be the
case?<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>Of course, linear and cubic
trends can be sometimes both significant, but I was slightly worried seeing
this strong concordance in this case.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal style='margin-left:35.4pt'>(Also, does any of you have a
better/best/gold standard way to model 3-level linear contrasts?
mathematically, in [-1 0 1], the middle condition is basically switched off,
isn’t it.)<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'>I’m not sure, but it may reflect a property in your data. If the
first two levels show about the same mean physiological response and only the
third level differs, then your observation is what you should expect.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'>Best,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Verdana","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
</div>
<div>
<p class=MsoNormal>Anyway, thanks very much for a quick reply!<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>Best wishes, Jonas<o:p></o:p></p>
</div>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<div>
<div>
<p class=MsoNormal><span style='font-size:13.5pt;font-family:"Bitstream Vera Sans","serif";
color:black'><br>
<a href="http://jonasobleser.com">http://jonasobleser.com</a><o:p></o:p></span></p>
</div>
<div>
<div>
<p class=MsoNormal><span style='font-size:13.5pt;font-family:"Bitstream Vera Sans","serif";
color:black'>+49 171 6993337 mobile<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:13.5pt;font-family:"Bitstream Vera Sans","serif";
color:black'>+49 341 304 7980 home<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:13.5pt;font-family:"Bitstream Vera Sans","serif";
color:black'><o:p> </o:p></span></p>
</div>
</div>
<p class=MsoNormal><span style='font-size:13.5pt;font-family:"Bitstream Vera Sans","serif";
color:black'><o:p> </o:p></span></p>
</div>
<p class=MsoNormal><span style='font-size:13.5pt;font-family:"Bitstream Vera Sans","serif";
color:black'><br>
<br>
</span><o:p></o:p></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p>----------------------------------<o:p></o:p></p>
<p>The aim of this list is to facilitate the discussion between users of the
FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and
EEG analysis.<o:p></o:p></p>
<p>http://listserv.surfnet.nl/archives/fieldtrip.html<o:p></o:p></p>
<p>http://www.ru.nl/fcdonders/fieldtrip/<o:p></o:p></p>
</div>
</body>
</html>
<p>----------------------------------</p>
<p>The aim of this list is to facilitate the discussion between users of the FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis.</p>
<p> http://listserv.surfnet.nl/archives/fieldtrip.html</p>
<p> http://www.ru.nl/fcdonders/fieldtrip/</p>