<div class="gmail_quote"><div>Hello Lin,</div><div> </div><div>In your code you need to specify an event type. To find out what the event type is, you can run ft_definetrial() with cfg.trialdef.eventtype='?', and it will tell you what event types are present in the file (see my sample below):</div>
<div> </div><div>addpath 'C:\Program Files\MATLAB\R2010a\toolbox\fieldtrip-20120512';</div><div>cd 'C:\Users\SJPA\Documents\MATLAB';</div><div>cfg = [];<br>cfg.dataset = 'myneuroscanfile.cnt';</div>
<div>cfg.trialdef.eventtype = '?'</div><div>cfg = ft_definetrial(cfg);</div><div> </div><div> </div><div> </div><div>After that, you can use that event type, along with cfg.dataset and cfg.trialdef.eventvalue, to define trials and import the data; see my example below (this code will take a continuous file but it will epoch it while importing, so you will end up with epoched data; also note, as far as I know, you don't need to specify cfg.headerfile)</div>
<div> </div><div> </div><div> </div><div>addpath 'C:\Program Files\MATLAB\R2010a\toolbox\fieldtrip-20120512';</div><div>cd 'C:\Users\SJPA\Documents\MATLAB';</div><div> </div><div>cfg = [];<br>
cfg.dataset = 'myneuroscanfile.cnt';</div><div>cfg.trialdef.eventtype = 'trial';</div><div>cfg.trialdef.eventvalue = [4 5 6 7];</div><div>cfg = ft_definetrial(cfg);</div><div> </div>
<div>cfg.channel = [];</div><div>cfg.continuous = 'yes';</div><div>data = ft_preprocessing(cfg);</div><div> </div><div> </div><div> </div><div>I noticed your e-mail signature says you are at Peking University; I am actually also at the psychology department in PKU and will be here until July 17th, if you need assistance feel free to contact me!</div>
<div> </div><div>Best,</div><div>Steve Politzer-Ahles</div><div> </div><div> </div><div> </div><div> </div><blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid" class="gmail_quote">
<br>
Message: 2<br>
Date: Sun, 8 Jul 2012 15:50:20 +0800 (CST)<br>
From: ?? <<a href="mailto:bertram0611@pku.edu.cn">bertram0611@pku.edu.cn</a>><br>
To: <a href="mailto:fieldtrip@science.ru.nl">fieldtrip@science.ru.nl</a><br>
Subject: [FieldTrip] How to import *.cnt datafile from NeuroScan?<br>
Message-ID:<br>
<<a href="mailto:283648358.226.1341733820039.JavaMail.root@bj-mail07.pku.edu.cn">283648358.226.1341733820039.JavaMail.root@bj-mail07.pku.edu.cn</a>><br>
Content-Type: text/plain; charset=utf-8<br>
<br>
Dear FieldTrip list members,<br>
<br>
I wanna analyse the *.cnt datafile from NeuroScan. But I don't know how to do that. Because there are not detailed scripts. In my exp, the trigger code is 14. I don't what is eventvalue that equals trigger code? My EEG was recorded from 62 Ag/AgCl electrodes mounted in an elastic cap (Quick-Cap, NeuroScan Inc.,Herndon, Virginia, USA). Recordings were referenced to the left mastoid, but rereferenced to linked mastoids offline. The horizontal and vertical electrooculogram was also monitored. Electrode impedances were kept below 5 kO. The EEG and electrooculogram were amplified with a band-pass from DC to 70Hz and the sample rate was 500 Hz.The epoch interval was 1200ms, ranging from 200ms before the onset of the critical word to 1000 ms after it.I used a 100-ms poststimulus baseline for the critical words.<br>
can you give an example that analysing *.cnt data.<br>
my script and problems as follows:<br>
cfg = []<br>
cfg.datafile = 's01.cnt'<br>
cfg.headerfile = 's01.cnt'<br>
cfg.channel = 'all'<br>
cfg.eventvalue = '14'<br>
raw = ft_definetrial(cfg);<br>
Warning: no trialfun was specified, using trialfun_general<br>
> In ft_definetrial at 123<br>
evaluating trialfunction 'trialfun_general'<br>
??? Reference to non-existent field 'trialdef'.<br>
<br>
Error in ==> trialfun_general at 29<br>
if isfield(cfg.trialdef, 'eventvalue') && isempty(cfg.trialdef.eventvalue ),<br>
cfg.trialdef = rmfield(cfg.trialdef, 'eventvalue' ); end<br>
<br>
Error in ==> ft_definetrial at 175<br>
[trl, event] = feval(cfg.trialfun, cfg);<br>
best regards<br>
<br>
--<br>
Lin Cai<br>
Department of Psychology, Peking University, Beijing 100871, P.R.China<br>
<br>
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End of fieldtrip Digest, Vol 20, Issue 12<br>
*****************************************<br>
</blockquote></div><br><br clear="all"><br>-- <br>Stephen Politzer-Ahles<br>University of Kansas<br>Linguistics Department<br><a href="http://www.linguistics.ku.edu/">http://www.linguistics.ku.edu/</a><br>