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Lin, Peter (NIH/NINDS) [F] wrote:
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<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">Hi I am working with
movement data (finger abduction and
sequence) with EEG and studying phase lag and coherence. Is there any
way to
use EEGlab to Hilbert transform the data? <br>
</span></font></p>
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EEGLAB does not support Hilbert transforms, but the signal processing
toolbox has a built-in "hilbert" function. The advantage of the Hilbert
function is that it returns more accurate phase information that
standard time-frequency transforms. The drawback is that you are
usually not allowed to visualize results of hilbert transform at
different frequencies (although you may bandpass the signal at the
frequency of interest and then apply an hilbert transform). If anyone
has functions to compute hilbert transform of the EEGLAB structures, we
would for sure be interested in helping make them avaiable as a plugin.
<br>
<br>
The following paper basically shows that Hilbert and standard wavelet
methods are roughly equivalent:<br>
<br>
Comparison of Hilbert transform and wavelet methods for the analysis of
neuronal synchrony<br>
J Neurosci Methods. 2001 Oct 30;111(2):83-98.<br>
Michel Le Van Quyen, Jack Foucher, Jean-Philippe Lachaux, Eugenio
Rodriguez, Antoine Lutz, Jacques Martinerie and Francisco J. Varela<br>
<br>
Best,<br>
<br>
Arno<br>
<br>
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