# CFC - for Hilbert transform

Hi,

I would like to know if it is possible to determine the signal amplitude of a raw data (LFP) from the Hilbert transform?

And of the value of amplitude and frequency phase, develop the CFC analysis and determine my variables reliably.

Yes, that’s definitely possible. I discuss this quite a bit in the ANTS book and in my youtube videos (at least for the Hilbert transform; I don’t have videos on CFC but that’s in the book).

Thanks, but not to be boring.

I can define this data for the routine:

%%
nonmodulated amplitude = 2; % increase this to get less modulation; you’ll see that this is reflected in the MI value
% analysis minute by minute
SEG = 0;
SEG = SEG +60;
SEG2 = SEG - 60;
srate = 500;
lfp = A1 (:, SEG2 * srate + 1: SEG * srate);
srate = 500;
dt = 1 / srate;
time = dt: dt: length (lfp) / srate;

clear Comodul

Pf1 = 1 %%this data
Pf2 = 10 %%this data
Af1 = 10 %%this data
Af2 = 100 %%this data

figure (3), clf
[MI, MeanAmp] = ModIndex_v1 (lfp, srate, Pf1, Pf2, Af1, Af2)

tic
PhaseFreqVector = 1: 1: 10; %%this data
AmpFreqVector = 10: 1: 100; %%this data

PhaseFreq_BandWidth = 1;
AmpFreq_BandWidth = 1;

Comodulogram = zeros (length (PhaseFreqVector), length (AmpFreqVector));

from the visual analysis of PSD peaks (LFP), but …

How could I put together what we would generate from the Hilbert transform, apply it to the CFC and corroborate the data with the PSD?

I’m not really sure what your question is, Heitor. The Hilbert transform is used in signal processing to get an analytic signal from which you can extract estimates of instantaneous amplitude and phase. It’s basically the same thing as complex wavelet convolution or STFFT. It’s like, if you want to get from A to B, you can drive a Honda or a Toyota or a Chevy, and you’ll still get to where you’re going.

Thanks for answering. then I cannot carry out the development. i would like to extract hilbert data more reliably for cfc, but the way i have it is not feasible. because I need to visualize the evidence of lower frequency phases by modulating higher frequency amplitudes.