Hi,<br><br>Although this might be a late reply, I would like to contribute my two cents and also would be glad to hear any comment.<br><br>To calculate PLV<br>1. get and real and imaginary part of of Fourier coefficents for each trial for each sensor<br>
<br>
cfg.method = 'wavelet'; % 'mtmfft' works as well
although I do not really look into the differences between the two<br>cfg.keeptrials = 'yes';<br>cfg.output = 'fourier';<br> fourier_coefficent = ft_freqanalysis(cfg, data);<br>
<br>2. calculate the phase <br>
<br>
phase = arctangent of the imaginary Fourier coefficient divided by the real one.<br>
<br>
3. calculate the phase difference between two sensors, i and j (Melloni et al. Journal of neuroscience 2007, 27:2858)<br>
<br>
phaseij = the phase of the sensor i multiplied by the complex conjugate of the second sensor j<br>
<br>
4. calculate the PLV<br>
<br>
PLVij = the absolute value of the mean of the phaseij across all the trials<br><br><div class="gmail_quote">On Thu, Jun 14, 2012 at 11:16 PM, Simon-Shlomo Poil <span dir="ltr"><<a href="mailto:poil.simonshlomo@gmail.com" target="_blank">poil.simonshlomo@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Qi,<br>
<br>
I also don't know how to calculate the phase locking value in<br>
Fieldtrip. But you can do it in the Neurophysiological Biomarker<br>
Toolbox <a href="http://www.nbtwiki.net/doku.php?id=tutorial:phase_locking_value" target="_blank">http://www.nbtwiki.net/doku.php?id=tutorial:phase_locking_value</a><br>
<br>
It's a toolbox for EEGLAB, but it should be possible to either use the<br>
functions directly on you fieldtrip signal, or simply convert the<br>
signal to eeglab format..<br>
<br>
Good luck! :)<br>
Simon-Shlomo Poil<br>
<br>
2012/6/13 qi li <<a href="mailto:lihqih@gmail.com">lihqih@gmail.com</a>>:<br>
<div class="HOEnZb"><div class="h5">> Hi there,<br>
><br>
> I am wondering whether fieldtrip has a function to compute the<br>
> instantaneous phase and phase locking value. Thanks!<br>
><br>
> Qi<br>
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