I am analysing EEG data looking for theta-gamma tPAC. I already got my results for standard tPAC (coupling of phase and amplitude within the same electrode) and now I want to broad my project by looking for inter-regional tPAC. However, I got no results when using the same parameters I used for the initial tPAC analysis.
These are the parameters:
This is what I got for standard tPAC with those parameters for one single trial:
And this is what I am getting for inter-regional tPAC with those exact parameters from the screenshot: (black for every electrode, even for the electrode I am using as a seed for fp (FT7), where I already know from the previous screenshot that there's some coupling between phase of FT7 and amplitude of FT7)
However, if I increase the lenght of the sliding time window to 0.7s or if I change the theta frequency range from 3-6 to 3-8, I got results. These are by applying both changes simultaneously:
Given that I have different results for the coupling between phase and amplitude in one particular electrode by using the two methods, I wonder whether they're calculating tPAC differently or if there's another reason why this is happening. Because I am broadening my initial analysis I'd like to maintain the same parameters so I don't know if I can obtain some results by maintaining them.
Thank you so much in advance!