<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=Windows-1252">
<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;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 2.0cm 2.0cm 2.0cm;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body lang="IT" link="blue" vlink="#954F72" style="word-wrap:break-word">
<div class="WordSection1">
<p class="MsoNormal"><span lang="EN-GB">Dear Fieldtrip community,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">I am using Fieldtrip to run a source localization of TMS evoked potentials (TEPs) on EEG data. I decided to use the MNE method following the online tutorial (<a href="https://www.fieldtriptoolbox.org/tutorial/minimumnormestimate/">https://www.fieldtriptoolbox.org/tutorial/minimumnormestimate/</a>).
I was able to reproduce the analysis using my data and create the source localization figure. However, I noticed that the plot is representing the power of the data (avg.pow), which is not exactly what I was aiming for. Is there a way to create and plot the
amplitude rather than the power of the signal - which I suppose is stored in the ‘moment‘ (.mom) field?
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">From what I saw, it does not seem possible to compute such operation using the Fieldtrip functions showed in the tutorial. The problem seems to be that the structure of .mom is not equal to the pow’s one. Specifically,
avg.pow is a 20484x3000 matrix of N source points x N time points. The .mom field contains instead a 20484x1 cell array and each cell is a 3x3000 matrix with the three rows supposed to be the three coordinates x,y and z of the source vector and the columns
representing the time points. I was able to obtain a data structure similar to pow (20484x3) by using custom-made scripts to compute the
<b>average</b> of the three axes (x, y, z) for each time point (3000) and source (20484). Is this method correct? Is there a better way to extrapolate the amplitude for each time x source point and to plot it?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">Thanks in advance!</span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph;line-height:150%">
*******************************************************<o:p></o:p></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph;line-height:150%">
<i><span lang="EN-GB" style="font-family:"Times New Roman",serif">Chiara Spaccasassi<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph;line-height:150%">
<i><span lang="EN-GB" style="font-family:"Times New Roman",serif">Post-doctoral Researcher<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph;line-height:150%">
<i><span lang="EN-GB" style="font-family:"Times New Roman",serif">Centre for studies and research in Cognitive Neuroscience (CsrNC)<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph;line-height:150%">
<i><span lang="EN-GB" style="font-family:"Times New Roman",serif">Department of Psychology, University of Bologna<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph;line-height:150%">
<i><span style="font-family:"Times New Roman",serif">Via Rasi e Spinelli, 176, 47521, Cesena, Italy<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph;line-height:150%">
<span style="font-family:"Times New Roman",serif"><o:p> </o:p></span></p>
<p class="MsoNormal">Inviato da <a href="https://go.microsoft.com/fwlink/?LinkId=550986">
Posta</a> per Windows 10<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>