Canolty map calculation process

Dear Brainstorm Community,

I have a few questions regarding the process during which Brainstorm directly generates a Canolty map from the imported raw signal.

1.In the upper part of a Canolty map the Time-frequency plot of mean power modulation can be seen.
I do not understand how the program calculates it:
It is calculated and plotted with the same steps as the tPAC is calcualted (which is clearly described in Samiee et al. 2017)?
Or the program plots the power spectral density in this time-frequency decomposition ? There is also a color bar without unit. If a name for this unit should be given, what would it be?
Moreover, how the phases of the averaged nesting frequency are found and matched to the Time-frequency decompostion? Does the program use Hilbert transform?
2. The local field potential was recorded with 5 KHz sampling rate and the plotted Canolty map goes until 250 Hz. If I want to see what is above 250 Hz, should I increase the sampling rate? (I did not find options in the pipeline where I could set it but maybe there is one.)

Kind regards,
Berki Ádám

In the upper part of a Canolty map the Time-frequency plot of mean power modulation can be seen.
I do not understand how the program calculates it:
It is calculated and plotted with the same steps as the tPAC is calcualted (which is clearly described in Samiee et al. 2017)?

As mentioned in the tutorial "Phase-amplitude coupling: Example" (https://neuroimage.usc.edu/brainstorm/Tutorials/Resting#Canolty_maps), the method is described in this article:

Canolty RT , Edwards E, Dalal SS, Soltani M, Nagarajan SS, Kirsch HE, Berger MS, Barbaro NM, Knight RT. High gamma power is phase-locked to theta oscillations in human neocortex. Science , 2006 Sep 15;313(5793):1626-8.

For implementation details in Brainstorm, please refer directly to the code (the Matlab debugger can be a great to understand the code step by step):
https://github.com/brainstorm-tools/brainstorm3/blob/master/toolbox/process/functions/process_canoltymap.m#L371

The local field potential was recorded with 5 KHz sampling rate and the plotted Canolty map goes until 250 Hz. If I want to see what is above 250 Hz, should I increase the sampling rate?

The sampling rate is indeed hard coded to be limited to 250Hz:
https://github.com/brainstorm-tools/brainstorm3/blob/master/toolbox/process/functions/process_canoltymap.m#L378

@eflorin @Samiee @Sylvain
What is the explanation for this limitation?

If you want to increase this limit, increasing the sampling rate would have no effect, you need to modify the code of process_canoltymap.m.

Sorry for this omission, I was searching for it in the wrong tutorial section (only EEG).

Thank you for the article! Indeed, it is described very well in the supplementary material.

Thank you for the source, too!
I was able to modify the code (first "programming" experience in my life :)) )

I am greatful for your explanation, Thank you again, Francois!

Kind regards,
Ádám

@eflorin @Samiee @Sylvain
What is the explanation for this limitation?

Not sure why we have this limit, I think Esther transferred the original code to brainstorm. Probably it was hard coded in that version and did not get updated!
@Francois