Phase Slope Index Code

EEG
#1

Hi Mike,

I found two different implementations of the code you adapted from Nolte et al. to calculate PSI and was wondering which one was correct. If I am not mistaken, the only difference between the two versions is in this line of code:

Version 1 : cs(:,:,freqi) = cs(:,:,freqi) + tempfftdat’*tempfftdat;
Version 2 : cs(:,:,freqi) = cs(:,:,freqi) + tempfftdat’*conj(tempfftdat);

I noticed that with the first version of the code, the connectivity value i to j is equal to - ( j to i ), whereas this does not occur with the second version of the code.

Thank you!
Luca

#2

Hi Luca. Thanks for your careful read. I see Version 2 in the function data2psiX.m, which is code from Nolte that I modified. Can you tell me where you see Version 1?

#3

Hi Mike, thank you for the quick reply. I actually googled the name of the function (data2psiX.m) and I found the first version of the code in GitHub (https://github.com/vncntprvst/tools/blob/master/AnalyzingNeuralTimeSeriesData/code/data2psiX.m).

#4

Ah, I see. That’s not my github, though. Probably best to get the code from my repository.