[FieldTrip] questions itc/plf calculation via hilbert transformations

Russell G Port russgport at gmail.com
Thu Dec 5 23:36:56 CET 2013

Hi fellow fieldtippers,

I have a question that brought around by an answer I previously received.
  For data analyzed with ft_freqanalysis and using the 'wavelet' option I
can computer ITC/PLF via,

tmpdat = freq.fourierspctrm;
tmpdat = tmpdat./abs(tmpdat); ; % this will normalize each trial for its
itc = abs(mean(tmpdat)); % this will give the itc

thank you again Jan-Mathijs for this insight

I am now trying to calculate ITC via hilbert transformation, putting my VE
data through

ft_preproc_hilbert. Can I just use the cfg.option = 'imag', to get the
imaginary component of

the analytic signal, since this is what i use with wavelets (i.e. what the

tmpda =tmpdat./abs(tmpdat) achieves). Then I would just repeat the last
line itc =

abs(mean(tmpdat)). I only hesitate because on several of the mailing list
emails people have

suggested doing cfg.option = 'angle' (which computes the imaginary
component (tmpdat./abs(tmpdat)  then uses the angle function (angle()).
Have I been calculating ITC wrong for my wavelets? Or should i just the the
cfg.option = 'imag' and mimik my wavelet based ITC.


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