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<font size="2" face="Dialog">Dear Sybille,</font> </p>
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<font size="2" face="Dialog">the plv option is now within ft_connectivityanalysis. I was successful with the code given below (ft_freqanalysis changed a bit in newer versions of fieldtrip so there might be some small corrections necessary). As much as I know, a plv analysis on source activity is not implemented as one of fieldtrip's high-level functions, but could be done by hand. One possibility is to use source analysis to identify regions of interest, which can then be used as "virtual electrodes" for ft_freqanalysis and ft_connectivityanalysis, just as the real electrodes in sensor space data. In order for that to work, you need to reconstruct single trial source activity at your ROIs. How this is done depends on the method you use for source analysis. There are some recent postings where a method is described for an LCMV beamformer.</font> </p>
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<font size="2" face="Dialog">Hope this helps,</font> </p>
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<font size="2" face="Dialog">Gregor</font> </p>
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<font size="2" face="Dialog">cfg_tfr = [];</font> </p>
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<font size="2" face="Dialog">cfg_tfr.output = 'fourier';</font> </p>
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<font size="2" face="Dialog">cfg_tfr.channel = 'all';</font> </p>
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<font size="2" face="Dialog">cfg_tfr.method = 'mtmconvol'</font> </p>
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<font size="2" face="Dialog">cfg_tfr.taper = 'hanning'</font> </p>
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<font size="2" face="Dialog">cfg_tfr.toi = -0.6:0.02:1</font> </p>
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<font size="2" face="Dialog">cfg_tfr.foi = [8 9 10 11 12];</font> </p>
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<font size="2" face="Dialog">cfg_tfr.t_ftimwin = 7./cfg_tfr.foi;</font> </p>
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<font size="2" face="Dialog">cfg_tfr.channelcmb = {'EEG', 'EEG'}</font> </p>
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<font size="2" face="Dialog">freq_output = ft_freqanalysis(cfg_tfr,data);</font> </p>
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<font size="2" face="Dialog">cfg_con = [];</font> </p>
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<font size="2" face="Dialog">cfg_con.method = 'plv';</font> </p>
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<font size="2" face="Dialog">plv = ft_connectivityanalysis(cfg_con, freq_output);</font> </p>
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<font face="Dialog" STYLE="font-size: 10pt"><br>--
<BR>Dr. rer. nat. Gregor Volberg <gregor.volberg@psychologie.uni-regensburg.de> ( mailto:gregor.volberg@psychologie.uni-regensburg.de )
<BR>University of Regensburg
<BR>Institute for Experimental Psychology
<BR>93040 Regensburg, Germany
<BR>Tel: +49 941 943 3862
<BR>Fax: +49 941 943 3233
<BR><a href="http://www.psychologie.uni-regensburg.de/Greenlee/team/volberg/volberg.html
">http://www.psychologie.uni-regensburg.de/Greenlee/team/volberg/volberg.html
</a><BR><br><br></font>>>> sibylle <s.mohr@psy.gla.ac.uk> 4/7/2011 12:55 PM >>><br>Dear Fieldtrippers,<br><br>I have a couple of question and I hope someone can help me:<br>How is it possible to compute plv (for freq data)?<br>As far as I can remember there used to be an option within <br>ft_sourcedescriptives, which seems to have disappeared.<br>How can one use plv to determine connectivity in source space?<br><br>Thanks a lot & best wishes,<br><br>Sibylle<br><br><br>_______________________________________________<br>fieldtrip mailing list<br>fieldtrip@donders.ru.nl<br><a href="http://mailman.science.ru.nl/mailman/listinfo/fieldtrip">http://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br>
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