<div dir="ltr"><div><div>Hi All,<br><br></div>Thank you all for your help. Please excuse the tardiness of my response. For anyone in the future who wishes to define trials via sample numbers I thought I would post this code my colleague came up with. It is surely not the most elegant way to go about defining trials, but it works so I hope it helps someone out there.<br><br>% % Segmenting based on sample numbers<br></div><div>% % currently shown to create two trials for example<br><br></div><div>data.cfg = rmfield(data.cfg,'trl'); <br>beginTrial = [2000,7000]; %beginning sample numbers <br>endTrial = [5000,10000]; %end sample numbers <br><br>for numOfTrials = 1:2 <br> data_artclean.cfg.trl{numOfTrials,1} = beginTrial(numOfTrials);<br> data_artclean.cfg.trl{numOfTrials,2} = endTrial(numOfTrials);<br> data_artclean.cfg.trl{numOfTrials,3} = 0;<br>end<br><br>cfg.trl = cell2mat(data.cfg.trl);<br>data_seg = ft_redefinetrial(cfg, data);<br><br></div><div>Thanks,<br></div><div>Peter<br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jun 29, 2015 at 10:16 AM, Pelt, S. van (Stan) <span dir="ltr"><<a href="mailto:stan.vanpelt@donders.ru.nl" target="_blank">stan.vanpelt@donders.ru.nl</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div link="blue" vlink="purple" lang="NL">
<div>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Hi Peter,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US">In addition to Steve’s perfect suggestion, you might want to take a look at this example script, which basically is a data-driven way to define
trials:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US"><a href="http://www.fieldtriptoolbox.org/example/detect_the_muscle_activity_in_an_emg_channel_and_use_that_as_trial_definition" target="_blank">http://www.fieldtriptoolbox.org/example/detect_the_muscle_activity_in_an_emg_channel_and_use_that_as_trial_definition</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US">Here, co-recorded EMG-data is used to define trials, but in your case you can use (some parameter in) your MEG data (e.g., some ‘cleaniness’ measure).<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Best,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Stan<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Consolas">--<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Consolas">Stan van Pelt, PhD<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Consolas" lang="EN-US">Donders Institute for Brain, Cognition and Behaviour<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Consolas" lang="EN-US">Radboud University<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Consolas" lang="EN-US">Montessorilaan 3, B.01.34<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Consolas" lang="EN-US">6525 HR Nijmegen, the Netherlands<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Consolas">tel: <a href="tel:%2B31%2024%203616288" value="+31243616288" target="_blank">+31 24 3616288</a>
<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d" lang="EN-US"><u></u> <u></u></span></p>
<div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0cm 0cm 0cm">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"" lang="EN-US">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"" lang="EN-US"> <a href="mailto:fieldtrip-bounces@science.ru.nl" target="_blank">fieldtrip-bounces@science.ru.nl</a> [mailto:<a href="mailto:fieldtrip-bounces@science.ru.nl" target="_blank">fieldtrip-bounces@science.ru.nl</a>]
<b>On Behalf Of </b>Stephen Politzer-Ahles<br>
<b>Sent:</b> maandag 29 juni 2015 15:32<br>
<b>To:</b> <a href="mailto:fieldtrip@science.ru.nl" target="_blank">fieldtrip@science.ru.nl</a><br>
<b>Subject:</b> Re: [FieldTrip] Help Manually Defining Trials<u></u><u></u></span></p>
</div><div><div class="h5">
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt">Hi Peter,<br>
<br>
<a href="http://www.fieldtriptoolbox.org/reference/ft_definetrial" target="_blank">http://www.fieldtriptoolbox.org/reference/ft_definetrial</a> describes the format of the trial definition matrix; you can simply create a matrix like this using the times that you would like
to choose for your epochs, and then run ft_preprocessing() with this matrix as the input for cfg.trl. (This is basically a combination of methods (1) and (2) that you suggested below.)<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">Best,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">Steve<br clear="all">
<u></u><u></u></p>
</div>
<div>
<div>
<div>
<div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><u></u> <u></u></p>
</div>
<p class="MsoNormal">Stephen Politzer-Ahles<br>
New York University, Abu Dhabi<br>
Neuroscience of Language Lab<br>
<a href="http://www.nyu.edu/projects/politzer-ahles/" target="_blank">http://www.nyu.edu/projects/politzer-ahles/</a><u></u><u></u></p>
</div>
</div>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal">On Mon, Jun 29, 2015 at 2:00 PM, <<a href="mailto:fieldtrip-request@science.ru.nl" target="_blank">fieldtrip-request@science.ru.nl</a>> wrote:<u></u><u></u></p>
<p class="MsoNormal"><br>
<br>
Message: 1<br>
Date: Sun, 28 Jun 2015 23:51:19 -0400<br>
From: Peter Lyons <<a href="mailto:plyons@udel.edu" target="_blank">plyons@udel.edu</a>><br>
To: FieldTrip discussion list <<a href="mailto:fieldtrip@science.ru.nl" target="_blank">fieldtrip@science.ru.nl</a>><br>
Subject: [FieldTrip] Help Manually Defining Trials<br>
Message-ID:<br>
<CALq-V2qi104MwTnq26qr4EwKPkZkBMEBzstS5JPRxZKVMrr=<a href="mailto:sw@mail.gmail.com" target="_blank">sw@mail.gmail.com</a>><br>
Content-Type: text/plain; charset="utf-8"<br>
<br>
Dear All,<br>
<br>
My name is Peter Lyons, and I am a researcher at the University of<br>
Delaware. Currently, I am conducting resting state EEG research with the<br>
intention of using Fieldtrip to calculate the power of different frequency<br>
bands as well as phase lag index between various sensors. My dataset is a<br>
continuous recording sampled at 1000 hz for 30 minutes. I do not have any<br>
events or triggers in my data.<br>
<br>
I would like to manually select the cleanest segments of my data following<br>
artifact rejection, and define them as trials.<br>
<br>
Theoretically, I see three ways to segment my data manually:<br>
<br>
1. Insert individual triggers throughout my data (at locations determined<br>
via ft_databrowser), and then define trials based on these triggers.<br>
<br>
2. Define trials based on a beginning and ending sample number.<br>
<br>
3. Use ft_databrowser to select segments of data as if they were<br>
artifacts, and then define these "artifacts" as trials instead of rejecting<br>
them from the dataset.<br>
<br>
Could anyone advise on how to code one of the above methods?<br>
<br>
Any help is welcome and appreciated!<br>
<br>
Thanks,<br>
Peter<br>
-------------- next part --------------<br>
An HTML attachment was scrubbed...<br>
URL: <<a href="http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20150628/d926ab81/attachment-0001.html" target="_blank">http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20150628/d926ab81/attachment-0001.html</a>><br>
<br>
------------------------------<br>
<br>
_______________________________________________<br>
fieldtrip mailing list<br>
<a href="mailto:fieldtrip@donders.ru.nl" target="_blank">fieldtrip@donders.ru.nl</a><br>
<a href="http://mailman.science.ru.nl/mailman/listinfo/fieldtrip" target="_blank">http://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br>
<br>
End of fieldtrip Digest, Vol 55, Issue 26<br>
*****************************************<u></u><u></u></p>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
</div>
</div></div></div>
</div>
<br>_______________________________________________<br>
fieldtrip mailing list<br>
<a href="mailto:fieldtrip@donders.ru.nl">fieldtrip@donders.ru.nl</a><br>
<a href="http://mailman.science.ru.nl/mailman/listinfo/fieldtrip" rel="noreferrer" target="_blank">http://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br></blockquote></div><br></div>