[FieldTrip] connectivity problem

[Gabriel Gonzalez Escamilla]

Dear Fieldtrip experts,

I finally understood how fieltrip computes the plv, so, my last e-mail has no sense now. Given say this, I have one question:

I've followed the fieltrip implementation to compute the PLV, and found that it takes the CSD, and normalizes it for the amplitude of the replicates, this is to divide the csd by the absolute of the same csd, then makes an average of the normalized csd's, to finally take the absolute of the average-normalized-csd as the PLV.  I think it can be summarized to something like, PLV = |E( csd/abs(csd) )|

I do not see the similarity with the clasical formula that appears in the papers PLV=| E{exp(i*I{X})} |, where I{X} is the imaginary of the cross-spectrum, and E|.| is the expected value; I cannot find the relationship between the implementation on fieltrip of the PLV and the formula on the papers.

Can anyone explain to me the relationship between the two approaches? or tell me the paper where it is explained?

Many thanks in advanced,
Gabriel

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